Repair library
Search by error code, model, brand or symptom. Results rank exact code matches first.
Diagnostic guides
Guide · Air Conditioner
PTAC not cooling (fan runs, air not cold)
Most PTAC no-cool calls are airflow (filter, coils), a wrong control setting or a failed compressor start component. Rule those out before suspecting the sealed system.
Guide · Air Conditioner
PTAC not heating (electric heat or heat pump)
PTACs heat with electric strip heat, a heat pump, or both. Heat pump models switch to strip heat in cold weather. Check settings, then the heater element and its limits, then the reversing valve.
Guide · Air Conditioner
PTAC error codes: how to read and clear them
Most PTAC brands store fault codes that can be shown with a button combination on the control (for example GE Zoneline uses a MODE + another key sequence on some models). Read the active code, fix the cause, then clear it.
Guide · Air Conditioner
Mini-split indoor unit dripping water
Indoor head leaks are almost always drain related: clogged pan or line, poor line slope, a failed condensate pump, or the head not level. Ice on the coil from low airflow or low charge is the next suspect.
Guide · Air Conditioner
Mini-split louvers (vanes) not moving
Vanes are driven by small stepper (swing) motors. Check the swing setting first, then the linkage for a broken clip, then the motor and its connector.
Guide · Air Conditioner
Mini-split smells (musty, dirty-sock, burning)
Musty or dirty-sock smell is biological growth on the coil, blower wheel and drain pan. Burning or electrical smell is a different job: stop the unit and inspect electrical parts.
Guide · Air Conditioner
AC/heat pump outdoor fan not spinning
On conventional units the usual causes are a failed fan capacitor, a seized motor or a contactor problem. On inverter mini-splits the fan is driven by the board and usually posts a fan error code.
Guide · Air Conditioner
Window AC smells musty or moldy
Standing water in the base pan, slime on the coil and a dirty blower wheel cause most odors. Units tilted wrong or stored wet are frequent offenders.
Guide · Air Conditioner
Air conditioner tripping the breaker
Find out when it trips: instantly (short to ground), at compressor start (hard start, bad capacitor, weak breaker) or after running (overload, loose connection heating up). Never upsize a breaker beyond the nameplate maximum.
Guide · Air Conditioner
Portable AC: exhaust hose, poor cooling and hot hose
Portable ACs depend on the exhaust hose. Long, kinked or extended hoses and leaky window kits pull hot air back in. Single-hose units also create negative pressure that draws in outside air.
Guide · Air Conditioner
Mini-split remote modes and settings explained
Many no-cool calls are remote settings: wrong mode, dry mode, auto with a wide band, sleep, eco or timers. Learn the mode icons and reset the remote before tearing into the system.
Guide · Dehumidifier
Dehumidifier error codes: general approach (sensor, bucket, pump)
Most portable dehumidifiers share the same code groups: sensor faults (E1/E2/EH), bucket (P1/FL), pump (E5/P2) and refrigeration protection (E3/EC). Power-cycle and basic checks fix many; sensor faults need a part.
Guide · Dehumidifier
Dehumidifier won't turn on (no display)
Check outlet, cord and any reset button first. Then internal fuse, transformer (on some whole-house units) and the control board.
Guide · Dehumidifier
Dehumidifier humidity reading wrong or runs nonstop
Compare against a known-good hygrometer. A dusty or failed humidity sensor, a set point too low for the space, or an undersized unit makes it run nonstop.
Guide · Dehumidifier
Dehumidifier blows warm air or smells
A working dehumidifier always discharges slightly warmer air than it takes in; that is normal. Musty smell comes from a dirty bucket, filter or coil.
Guide · Water Heater
Heat-pump (hybrid) water heater: slow recovery, noise, errors
Hybrids need enough room air and a clean air filter, a working condensate drain and the right mode. Many complaints are mode settings or a dirty filter. Refrigerant faults are sealed-system work.
Guide · Water Heater
Tankless water heater descaling (flush)
Scale insulates the heat exchanger, causing overheat codes and fluctuating temperature. Flush with a pump and descaling solution through the isolation valves.
Guide · Water Heater
Hot water recirculation pump problems
Check timer/settings, check valves, air in the loop and the pump itself. On tankless units with built-in pumps, a recirculation code may point to air or a leak in the loop.
Guide · Water Heater
Thermal expansion tank: check and replace
On closed systems (check valve or PRV), heated water has nowhere to expand. An expansion tank absorbs it. Its air charge should match the static water pressure.
Guide · Water Heater
Anode rod: inspect and replace
The sacrificial anode protects the tank from corrosion. When it is mostly consumed (core wire exposed), replace it. Powered anodes are an option where odor is a problem.
Guide · Water Heater
Tank water heater sediment flush
Sediment settles at the bottom, insulating gas burners and burying electric lower elements. Flush through the drain valve; heavily scaled tanks may need repeated flushes.
Guide · Air Conditioner
Air conditioner running but not cooling enough
Most no-cool calls on room units are airflow, installation or sizing problems, not hardware. Measure the temperature drop across the unit first, then work through filter, coils, air leaks and heat load before suspecting the sealed system.
Guide · Air Conditioner
Air conditioner blowing warm or room-temperature air
Warm air with a running fan means the compressor is not running or not pumping. Confirm the mode and setpoint, then check whether the compressor is actually starting before looking at capacitor, overload and contactor.
Guide · Air Conditioner
Air conditioner freezing up (ice on the coil)
Ice forms when the coil gets too cold, nearly always from low airflow or running in cool weather. Thaw first, then fix airflow. Repeated icing with good airflow suggests low charge, which is sealed-system work.
Guide · Air Conditioner
Air conditioner dripping or leaking water indoors
Condensate is supposed to drain outdoors. Indoor leaks come from wrong tilt, blocked drain openings or lines, a frozen coil melting off, or a cracked pan / failed pump.
Guide · Air Conditioner
Air conditioner short cycling (turns on and off too often)
Short cycling has many causes: oversized equipment, a badly placed thermostat or sensor, restricted airflow leading to icing, failing electrical parts, or refrigerant issues. Start with the cheap checks.
Guide · Air Conditioner
Air conditioner won't turn on (no display, no fan)
Confirm power from the outlet or breaker before blaming the unit. Room units often have a reset button on an LCDI/ALCI plug; mini-splits need power at the disconnect and a working remote.
Guide · Air Conditioner
Outdoor fan or indoor fan runs but compressor doesn't (capacitor & contactor)
On central AC and many room units, a weak run/start capacitor or burned contactor is the usual cause. Test the capacitor µF against its label and the contactor coil and contacts. A compressor that still won't run with good parts is sealed-system territory.
Guide · Air Conditioner
Air conditioner loud noise or vibration
Most noise is mechanical and easy: loose panels, fan blade striking ice or the shroud, worn motor bearings, or a poorly supported window unit. Electrical buzzing at the condenser often points to a contactor or capacitor.
Guide · Air Conditioner
Remote or thermostat not responding
Start with batteries and line of sight, then test the unit with its own controls. On central systems, confirm the thermostat is powered (24 V) and actually calling.
Guide · Air Conditioner
Mini-split indoor unit blinking light (reading the code)
A blinking pattern is a fault code. Count the blinks before you reset power, because a breaker reset erases the code. Then look it up for the brand and fix the cause.
Component test · Dryer
How to test a dryer thermal fuse
A thermal fuse is a one-time safety link that opens permanently when the exhaust gets too hot. It is a simple continuity test, but a blown fuse is a symptom: the real cause is almost always a restricted vent or a failed cycling thermostat.
Component test · Dryer
How to test a high-limit thermostat (dryer and similar heaters)
A high-limit is a normally-closed bimetal switch that opens if the heater area overheats and closes again when it cools. A room-temperature continuity test catches the common "stuck open" failure, but it cannot prove the opening temperature is right.
Component test · Dryer
How to test a dryer cycling (operating) thermostat
The cycling thermostat switches the heat on and off to hold the exhaust temperature. It should be closed when cold and open when hot. A stuck-closed unit overheats the dryer; a stuck-open unit gives no heat.
Component test · Refrigerator
How to test a refrigerator bi-metal defrost thermostat
The bi-metal (defrost termination thermostat) is wired in series with the defrost heater. It is closed only when the evaporator is cold and opens once the coil warms during defrost. Testing it at room temperature gives a false "bad" result: it must be cold.
Component test · Fundamentals
How to test an NTC thermistor (temperature sensor) and read a resistance chart
NTC thermistors are used in refrigerators, dryers, washers, dishwashers, AC units and water heaters. Resistance falls as temperature rises. You test them by measuring resistance at a known temperature and comparing it with the chart for that exact sensor family.
Component test · Range / Oven
How to test an oven RTD temperature sensor
Most electronic ovens use a platinum RTD probe, which works the opposite way to an NTC: resistance rises with heat. Many common sensors read about 1,080 Ω at room temperature and climb roughly 2 Ω per °F.
Component test · Dryer
How to test a dryer heating element
An electric dryer element is a resistance coil on 240 V. Test it across the terminals and to ground. Most read in the low teens of ohms; use R = V²/W from the element rating to check yours.
Component test · Range / Oven
How to test an oven bake or broil element
Bake and broil elements are 240 V resistance heaters. A good one reads somewhere in the teens to about 40 Ω depending on wattage, and never shows continuity to its metal sheath.
Component test · Dishwasher
How to test a dishwasher heating element
Many US dishwashers have a hidden or visible loop element under the tub. A good one reads in the tens of ohms. A leak to the tub trips the GFCI even when the resistance looks fine, so always check to ground.
Component test · Refrigerator
How to test a refrigerator defrost heater
The defrost heater (glass tube, metal sheath or foil type) melts frost off the evaporator a few times a day. A good heater reads in the low tens of ohms; use the wattage math to check the exact value.
Component test · Fundamentals
How to test a water inlet valve (single, dual and triple coil)
Inlet valves are solenoid valves. Each coil opens one water path. Test each coil for resistance; a coil can be fine yet the valve still fail mechanically (clogged screen or stuck plunger), so check flow and the screen too.
Component test · Washer
How to test a drain pump (washer and dishwasher)
Most drain pumps are small synchronous motors. Clear the filter and impeller first, then test the winding and the voltage. Published resistance values vary a lot by brand, so use the tech sheet for the number.
Component test · Dishwasher
How to test a dishwasher circulation (wash) pump motor
The wash motor pushes water to the spray arms. Older units use an AC induction motor; many newer ones use a brushless DC motor driven by the board. Rule out a jam and a filter clog before testing, and use the tech sheet for winding values.
Component test · Fundamentals
How to test a PSC motor (common, start and run windings)
Permanent split capacitor (PSC) motors are used in AC condenser and blower fans, some washer and dishwasher motors. Test the capacitor first, then the three windings. The two individual readings must add up to the start-to-run reading, and nothing may read to ground.
Component test · Fundamentals
How to test a shaded-pole fan motor
Shaded-pole motors are the simple, low-power AC motors with copper shading rings on the pole pieces. They have one winding, no capacitor and a weak starting torque, so they usually fail from dry bearings rather than burned windings.
Component test · Refrigerator
How to check an ECM / brushless DC fan motor (what you can test safely)
Many modern refrigerator fans are brushless DC motors with their electronics inside the motor. An ohmmeter cannot judge them reliably. The safe test is to confirm the supply voltage and control/feedback signals at the connector, then swap the motor if the signals are right.
Component test · Washer
How to test a universal (brushed) motor and its carbon brushes
Universal motors run on AC or DC through carbon brushes that rub on a commutator. Brushes wear out and are the most common failure. Check brush length and the commutator, then test the field and armature with a meter.
Component test · Fundamentals
How to test a door switch (refrigerator, dryer, dishwasher)
Door switches tell the control or the circuit that the door is shut. Some are normally open, some normally closed, and many have more than one set of contacts (light + fan, or start circuit). Test each pair in both door positions.
Component test · Washer
How to test a top-load washer lid switch / lid lock
Older top-loaders use a simple lid switch; most newer ones use a lid lock with a switch and a locking solenoid or motor. Test the switch contacts with the lid open and closed, and check the lock coil if there is one.
Component test · Fundamentals
How to test a micro switch / door interlock (COM, NO, NC)
Micro switches are small snap-action switches used as interlocks in microwaves, dishwashers, dryers and ice dispensers. Most have three terminals: common, normally open and normally closed. Test both contact pairs in both positions.
Component test · Washer
How to test a washer water-level pressure switch
The level switch reads air pressure trapped in a hose from the bottom of the tub. As water rises, pressure flips its contacts. Most failures are a clogged or leaking air hose, not the switch.
Component test · Furnace
How to test a gas furnace draft pressure switch (electrical and draft checks only)
The pressure switch proves the inducer is pulling enough draft before ignition is allowed. Test it with a meter (24 V across it) and a manometer against the set point printed on the switch. Gas valve, gas pressure and burner work are not covered: refer those to a licensed gas technician.
Component test · Dishwasher
How to test a float switch (dishwasher overfill and similar)
A float rides up with water and opens or closes a small switch under the tub. It stops overfill or flags a leak. Make sure the float moves freely before blaming the switch.
Component test · Dryer
How to test a dryer drive motor and its centrifugal switch
Dryer motors have a centrifugal switch that drops out the start winding once the motor is up to speed and, on most models, also closes the heater circuit. Test the windings at the motor and the switch contacts in both positions.
Component test · Fundamentals
How to test a mechanical timer (washer, dryer) contacts and motor
Mechanical timers are a small motor driving a cam stack that opens and closes many contacts. You need the timer chart (on the wiring diagram) to know which contacts should be closed at each dial position.
Component test · Range / Oven
How to test an infinite switch (electric surface element)
An infinite switch cycles a surface element on and off to set the heat level. Test the two line-to-element contact pairs on high and off. Also test the element itself before replacing the switch.
Component test · Fundamentals
How to test a selector or rotary switch (temperature, cycle, fan speed)
Selector switches route power to different circuits in each position. Like a timer, you need the switch chart from the wiring diagram to know which terminals should connect in each position.
Component test · Fundamentals
How to test a solenoid (dispenser, ice door, lock, diverter)
A solenoid is a coil that pulls a plunger when energized. Test the coil resistance, the voltage it receives, and that the plunger moves freely.
Component test · Refrigerator
How to test a refrigerator air damper (damper motor or damper control)
The damper opens and closes the cold-air path from the freezer to the fresh-food section. Older ones are mechanical (bellows), newer ones use a small motor driven by the board. Ice in the duct is a frequent cause.
Component test · Refrigerator
How to test an ice dispenser auger motor
The auger motor turns the auger in the ice bucket to push ice to the chute. A clump of frozen ice is the most common cause; test the motor only after the bucket is clear.
Component test · Dishwasher
How to test a wax motor (dispenser, lid lock, diverter actuators)
A wax motor is a slow thermal actuator: a small heater melts wax that pushes a plunger out over a minute or so. Test the heater resistance and watch it extend when powered.
Component test · Refrigerator
How to test a refrigerator mechanical defrost timer
Older refrigerators use a motor-driven timer that switches between cooling and defrost. Turning the advance screw lets you force defrost and test the contacts; terminal numbering varies, so use the diagram on the timer or tech sheet.
Component test · Refrigerator
How to test a refrigerator compressor start relay (PTC) and overload (electrical only)
The start device (PTC or current relay) and the overload plug onto the compressor terminals. Test them off the compressor. Electrical tests only: any compressor replacement, refrigerant work or brazing is a sealed-system job for an EPA 608-certified technician.
Component test · Dryer
How to test gas dryer valve coils (electrical test only)
The gas valve has solenoid coils that open when the igniter is hot. You may test the coils with a meter at their terminals with power off. Gas line, valve body and burner work is blocked: refer to a licensed gas technician.
Component test · Fundamentals
Main control board: power-in checks, outputs, and board vs load
Most boards that get replaced are fine; the real fault is usually missing input power, a bad load, or a harness. Prove the board has power in, is commanding an output, and that the output actually leaves the board before condemning it.
Component test · Fundamentals
User interface board, keypad and membrane switch testing
The UI is a display/keypad board fed with low-voltage DC from the main board. Separate three faults: no DC feed (main board or harness), a failed membrane (keypad tail), or a failed display/UI board.
Component test · Fundamentals
Relay on a control board: clicks but no output
A click only proves the coil moved. Burnt or pitted contacts can still fail to pass current. Measure across the contacts under load and at the output pin.
Component test · Fundamentals
Fuses on control boards and in-line fuses
Board fuses protect the board supply or a high-current output. A blown fuse almost always means something shorted downstream; replacing it without finding the cause usually ends in another blown fuse or a destroyed board.
Component test · Fundamentals
Low-voltage DC supply checks (5 V and 12 V rails)
Boards make low-voltage DC (often 5 V for logic and sensors, 12 V for relays, and other values on some products). A sagging rail causes many strange symptoms. Measure it at a known test point or connector, then remove loads one by one to find what drags it down.
Component test · Fundamentals
Run capacitor: microfarad test and tolerance
Run capacitors stay in the circuit while the motor runs. Test capacitance with a meter that has a µF range and compare to the label. Replace if outside the tolerance printed on the can, if open, or if bulged or leaking.
Component test · Fundamentals
Start capacitor test (and its relay or PTC)
Start capacitors are higher-µF electrolytic parts that are only in the circuit for a moment at start, removed by a relay, PTC or centrifugal switch. They fail open, shorted or bulged, often because the switching device kept them in circuit too long.
Component test · Air Conditioner
Dual run capacitor (HVAC condenser): testing both sections
A dual capacitor has C (common), HERM (compressor) and FAN terminals with two µF ratings in one can. Test C-HERM and C-FAN separately against the label; one section can fail while the other is fine.
Component test · Air Conditioner
Contactor (HVAC): coil, contacts and voltage drop
The contactor closes line voltage to the compressor and fan when it gets 24 V on its coil. Check coil voltage, coil resistance, contact condition and voltage drop across closed contacts.
Component test · Air Conditioner
24 V control transformer (HVAC)
The control transformer steps line voltage down to about 24 V AC for the thermostat, board and contactor coil. Measure primary and secondary under power; a blown low-voltage fuse means a short in the 24 V wiring, not a bad transformer.
Component test · Refrigerator
Refrigerator inverter compressor board: what is safe to check
Inverter boards make variable-frequency 3-phase power for the compressor. Electrical checks of the board and compressor terminals are allowed; anything that opens the sealed refrigerant system is EPA 608 work and blocked. Boards fail more often than compressors.
Component test · Air Conditioner
Mini-split outdoor inverter board: what is safe to check
Mini-split outdoor boards rectify line voltage to a high DC bus and drive the compressor and fan. Field checks are input power, communication, error codes and compressor winding balance. Board DC bus voltage is dangerous after shutdown.
Component test · Washer
Washer motor control unit / inverter board
Direct-drive and inverter washers use a motor control unit (MCU) that powers a 3-phase motor and reads a hall sensor or tach. Separate MCU, motor windings, hall sensor and harness before buying a board.
Component test · Washer
Hall sensor and tach generator (motor speed feedback)
Hall sensors are 3-wire devices (supply, ground, signal) that switch as magnets pass; tach generators are 2-wire coils that make a small AC voltage as the motor turns. Test the right way for the type.
Component test · Washer
Rotor position sensor (direct-drive motors)
On direct-drive motors the rotor position sensor sits on the stator and tells the inverter where the rotor magnets are. A bad sensor, cracked connector or water ingress gives motor errors even with good windings.
Component test · Washer
Washer door / lid lock assembly
A lock assembly has a lock actuator (solenoid, motor, or wax/PTC heater) and one or more switches that tell the board it is locked. Check the command from the board, the actuator, the switch and the strike.
Component test · Fundamentals
PTC / wax motor actuators (locks, dispensers)
Wax or PTC actuators heat a small element that expands wax and pushes a pin. They are slow by design and release only after cooling. Test resistance cold and confirm the board supplies voltage.
Component test · Dishwasher
Dishwasher door latch and door switch
The latch carries one or two switches that close when the door latches. The board will not start a cycle without them. Test continuity with the latch engaged and released.
Component test · Range / Oven
Oven door lock motor and lock switches (self-clean)
Self-clean ovens use a small motor or solenoid with cam switches that tell the control the lock position. A lock stuck after self-clean is often a cooled-down timing issue; check the motor, the switches and the control output.
Component test · Range / Oven
Glow-bar (hot surface) oven igniter: amp draw test
In gas ovens the glow-bar igniter is wired in series with the oven safety valve. The valve opens only when enough current flows, so a weak igniter can glow and still not open the valve. Measure amps, not just glow.
Component test · Range / Oven
Spark module and electrodes (gas cooktop)
The spark module makes a high-voltage pulse when an igniter switch on a valve stem closes. Constant clicking is usually moisture or a stuck switch; no spark is a cracked electrode, bad wire, or module.
Component test · Fundamentals
Flame sensor (flame rectification) microamp test
The flame sensor rod lets a tiny DC current flow through the flame. The board shuts the gas off if it does not see enough microamps. Clean first, then measure in series with a meter that reads DC µA.
Component test · Fundamentals
Furnace hot surface igniter (HSI)
Furnace HSIs are silicon carbide or silicon nitride elements. Measure cold resistance against the type; replace if open or far out of range. Handle only by the base.
Component test · Microwave
Magnetron: filament and filament-to-case tests (microwave)
The magnetron turns high voltage into microwave energy. An ohmmeter can catch an open filament or a filament shorted to the case, but it cannot prove the tube makes full power. Rule out the HV diode, capacitor and transformer before ordering a magnetron.
Component test · Microwave
Microwave high-voltage diode test
The HV diode works with the HV capacitor to double the transformer voltage for the magnetron. It is made of many junctions in series, so an ordinary meter only shows it is not shorted. A shorted diode is a classic cause of no heat with a loud hum.
Component test · Microwave
Microwave HV capacitor and bleeder resistor
The HV capacitor has a built-in bleeder resistor meant to drain its charge, but bleeders fail, so always discharge by hand. A shorted capacitor blows the HV fuse immediately. Resistance tests catch shorts; a capacitance reading is better.
Component test · Microwave
Microwave high-voltage transformer windings
The HV transformer has a primary, a high-voltage secondary and a low-voltage filament winding. Resistance checks find opens and shorts to the core; turn-to-turn shorts may still need a known-good comparison.
Component test · Fundamentals
Thermal cutouts and thermal fuses (TCO)
Thermal cutouts open when a part gets too hot. Some reset themselves when they cool; one-shot thermal fuses must be replaced. A blown cutout is a symptom: always find the overheating cause (blocked vent, failed fan, stuck relay) before closing up.
Component test · Range / Oven
Induction coil and IGBT power board (trained techs)
Induction boards rectify line voltage to a high DC bus and switch it at high frequency through IGBT transistors into a copper coil. Field work is limited to pan check, codes, input power, coil resistance and visual inspection; board-level repair is not a field job.
Component test · TV
TV LED backlight strips and LED driver
LED strips are wired in series strings and run from a constant-current driver at high DC voltage (often around 80-200 V total). One dead LED opens the string and the driver shuts down. Test LEDs with a backlight tester, not a meter diode range, and replace all strips as a set.
Component test · TV
T-con (timing control) board: board or panel?
The T-con converts video from the main board into the signals that drive the panel rows and columns. Loose ribbons, a blown T-con fuse or a failed T-con cause image faults; lines that stay fixed in the same place usually mean the panel itself.
Component test · TV
TV power supply board
The power supply board makes a standby voltage that is always on, then switches on the main rails when the main board sends a power-on signal. Check standby, then the power-on signal, then main rails. The primary side holds a high-voltage charge.
Component test · Fundamentals
Wi-Fi and smart modules
Most "bad Wi-Fi module" calls are network problems: wrong band, weak signal or router settings. Prove the network first, then power-cycle, then check the module supply and connector before replacing the module or board.
Component test · Fundamentals
Wiring harness and connectors: voltage drop, heat and corrosion
Harness and connector faults mimic failed parts. A loose or corroded terminal can pass a continuity test with no load and still drop voltage when current flows. Test voltage drop under load and replace both halves of a heat-damaged connection.
Component test · Fundamentals
GFCI and AFCI trips caused by appliances
Class A GFCIs must trip between about 4 and 6 mA of leakage to ground, so a slightly leaky heater or motor can trip them. AFCIs react to arcing signatures and also contain a ground-fault element with a higher threshold. Find out whether the appliance leaks before blaming the device.
Guide · Dehumidifier
Dehumidifier runs but collects little or no water
Rule out the easy causes first: setpoint already reached, room too cool, dirty filter, blocked airflow, or water going down a hose. Then confirm the compressor actually runs and the coil gets cold. A compressor that runs with a warm coil is a sealed-system failure: refer, do not repair.
Guide · Dehumidifier
Dehumidifier coils frosting or icing up
Light frost that comes and goes is normal: the defrost logic stops the compressor and runs the fan until it clears. Persistent ice means the room is too cold, airflow is restricted, the coil sensor has failed, or the refrigerant charge is low (sealed system, blocked).
Guide · Dehumidifier
Bucket full light (or P1/P2/Eb) stays on with an empty bucket
The bucket switch logic depends on a float and a small switch or magnet. A misseated or warped bucket, a float stuck with slime, or a failed float switch causes a false full signal. On units drained by hose, a loose hose connection can leak water into the bucket.
Guide · Dehumidifier
Dehumidifier fan not running
Confirm it is a real fault: many units run the fan on after the compressor stops, and some stop the fan at setpoint. Then check for a jammed blade, a loose motor plug, the fan capacitor (on PSC motors) and the board output.
Guide · Dehumidifier
Continuous drain or built-in pump not draining
Gravity drains fail from uphill or sagging hoses, a hose end sitting in water, missing washers or loose fittings. Pump drains fail from an unseated pump hose, kinks, a clogged pump filter screen or a dead pump. Most fixes are hose routing and cleaning.
Guide · Dehumidifier
Dehumidifier noisy or vibrating
Fan and compressor sound is normal. Abnormal noise usually comes from an unlevel unit, a loose panel or bucket, debris or ice hitting the fan, or a failing fan motor. Grinding on a brand-new unit suggests shipping damage.
Guide · Dehumidifier
Dehumidifier shuts off or will not stay running
Many stops are by design: setpoint reached, bucket full or removed, defrost, compressor restart delay or a scheduled rest. Real faults are overload trips from heat or poor airflow, power problems (extension cords, tripped breakers) and failing controls.
Guide · Dishwasher
Dishwasher top rack not cleaning (bottom rack OK)
When only the upper rack is dirty, the water is not getting up there. Check the upper spray arm, its feed tube and seal, the filter, and on units that switch between arms, the diverter.
Guide · Dishwasher
Dishwasher smells like burning
A burning smell is often plastic that fell onto the heater, but it can also be an overheating wire, connector or motor. Stop the unit and find the source before running it again.
Guide · Dishwasher
Dishwasher detergent dispenser door won't close or latch
Most cases are caked detergent on the latch or hinge. If the latch spring or the dispenser itself is broken, the dispenser assembly is replaced from inside the door.
Guide · Dishwasher
Dishwasher keeps beeping
A few beeps at the end of the cycle is normal on many models and can often be turned off in the settings. A repeating beep pattern, or beeps with flashing lights, is usually an error code.
Guide · Dishwasher
Dishwasher overflowing with suds
Almost always the wrong soap: hand dish soap, laundry detergent or too much detergent. Remove the suds, then run clean cycles.
Guide · Dishwasher
Dishwasher controls won't respond (control lock / child lock on)
The control lock blocks the keys. It is turned off with a key combination that differs by model.
Guide · Dishwasher
Rinse aid not dispensing
Check the setting and the cap first. Some models also have a rinse aid sensor that can report a fault.
Guide · Dishwasher
Dishwasher door falls open or slams down
Door springs or cables are broken or out of place.
Guide · Dishwasher
Dishwasher rack rusting
The vinyl coating has chipped and the steel is rusting. Repair kits or rack replacement.
Guide · Dishwasher
Dishwasher stops mid-cycle
The control usually stops for a code: door, water, drain or sensor faults. Read the code first.
Guide · Range / Oven
Oven light not working
Usually the bulb. If not, check the socket, switch or control.
Guide · Range / Oven
Oven door won't close fully
Usually hinges or a misseated door.
Guide · Range / Oven
Oven broil not working (bake works)
On electric ovens this is usually the broil element. Gas broil burners need a licensed technician for the gas side.
Guide · Range / Oven
Oven smoking
Usually spills or new-oven burn-off.
Guide · Range / Oven
Electric coil cooktop sparking
A damaged coil or burnt receptacle. Replace both if the terminals are burnt.
Guide · Range / Oven
Warming drawer not heating
Element, thermostat or control.
Guide · Range / Oven
Convection oven baking unevenly
Fan or element.
Guide · Range / Oven
Oven clock blank after power outage
Breaker, fuse or board.
Guide · Range / Oven
Oven air fry mode not crisping
Air fry needs the convection fan and the right tray.
Guide · Range / Oven
Range tips forward / anti-tip bracket missing
Install the anti-tip bracket.
Guide · Dishwasher
Dishwasher not draining / standing water
Work from cheapest to costliest: filter and sump, drain hose and disposer/air gap, then pump impeller, then pump power. Water that returns 30-60 minutes after a good drain points to the check valve.
Guide · Dishwasher
Dishwasher not cleaning well
Poor cleaning is usually low water temperature, a clogged filter, blocked spray-arm holes, or loading that blocks the arms. Check those before parts like the wash motor or heater.
Guide · Dishwasher
Dishwasher not filling
Confirm supply and hose first, then inlet screen and valve, then float/flow sensing and door latch.
Guide · Dishwasher
Dishwasher leaking
Rule out suds and loading, then inspect door gasket, inlet valve/fitting, pump seals and hoses. Leak codes mean water is already in the base pan.
Guide · Dishwasher
Dishes not drying
Many dishwashers (including most Bosch) dry by condensation, so rinse aid is essential and damp plastics are normal. On heated-dry models, check the element, vent and fan.
Guide · Dishwasher
Dishwasher won't start
Check power (breaker, under-sink switch/plug), lock and delay settings, then door latch switches and the control's thermal fuse where fitted.
Guide · Dishwasher
Bosch E15: leak tray flooded
E15 means water is in the base pan and the float is up. Dry the pan, reset the float, then find the leak - otherwise it comes back.
Guide · Dishwasher
Detergent not dissolving
Usually cool water, low spray pressure (filter/arms), or a dispenser door blocked by dishes.
Guide · Dishwasher
Dishwasher noisy (grinding, humming, thumping)
Grinding is usually debris at the pump or chopper; loud humming is a stalled or starved pump; thumping is spray arms hitting items.
Guide · Dishwasher
Door latch problems
The latch holds the door and signals the control. Debris, rack overload, gasket misalignment or a failed switch are usual causes; switches are usually sold with the latch.
Guide · Dryer
Electric dryer runs but no heat
Most electric no-heat calls come down to supply voltage (one breaker leg), a blown thermal fuse from a restricted vent, a tripped high-limit, or an open element. Always fix the airflow cause, or the new fuse will blow again.
Guide · Dryer
Gas dryer runs but no heat (electrical checks only)
On a gas dryer the electrical side of the burner can be diagnosed safely with gas and power off: thermal fuse, high-limit, cycling thermostat, igniter, flame (radiant) sensor and gas valve coils. Gas supply, gas lines, the valve body and gas pressure are off-limits: refer to a licensed gas technician.
Guide · Dryer
Dryer takes too long / vent restriction
Slow drying with heat present is almost always airflow. Check the whole exhaust path and its length before suspecting parts, then look at the moisture sensor and heat cycling.
Guide · Dryer
Dryer won't start
Separate 'dead' (no display) from 'display OK but no start'. Common causes are supply, door switch, thermal fuse (on designs where it is in the motor/control circuit), start switch, belt switch and the drive motor.
Guide · Dryer
Drum not turning (motor runs or hums)
Hand-turn the drum first: free-spinning means a broken belt; heavy or locked means rollers, idler, bearing or a jammed blower. Replace the idler with the belt when it is worn.
Guide · Dryer
Dryer squealing, thumping or grinding
Noise is mechanical wear in the drive and drum support: idler pulley, drum rollers, glides/felt seals, blower debris, or a belt with a flat spot. Identify by sound and hand-spin.
Guide · Dryer
Dryer stops early / clothes still damp
An auto cycle that ends early is usually the moisture sensor reading dry (residue, unlevel, small load). A dryer that stops mid-cycle and restarts later suggests motor overheating or a heat-related shutoff.
Guide · Dryer
Dryer overheating / cabinet too hot
Overheating is a fire risk. Restriction is the usual cause; after that, a cycling thermostat stuck closed, an element grounded to the housing, or a heater relay stuck on can keep heat on.
Guide · Dryer
Moisture sensor problems (auto dry wrong)
Moisture sensing uses two metal bars that wet clothes bridge. Residue, unlevel installs, small loads and loose wiring cause most complaints.
Guide · Freezer
Freezer not freezing (food soft, compressor running or not)
Rule out setting, load and door seal first, then airflow and condenser, then start components. On frost-free uprights, a choked evaporator from a defrost failure is a top cause. If the compressor runs steadily, the condenser is clean and the evaporator is not frosted but the cabinet still won't pull down, it is a sealed-system issue to refer out.
Guide · Freezer
Freezer frost build-up (gasket, manual defrost chest, frost-free failure)
Most chest and many small upright freezers are manual defrost, so some frost is normal and must be removed when it reaches about 1/4 inch. Fast or patchy frost near the door points to a leaking gasket or heavy door use. On frost-free uprights, frost on the coil behind the panel means the defrost system has failed.
Guide · Freezer
Freezer runs all the time
Freezers normally run 40-80% of the time at room temperature and more in a warm room. Check load, setting, room temperature, door seal and condenser before suspecting a part.
Guide · Freezer
Freezer not running (no compressor, or clicking)
Work from power to control to start components. A click-hum-click pattern every few minutes usually means the compressor is not starting: check the start relay/overload. If the relay is good and the compressor still won't start, compressor diagnosis and replacement is sealed-system work to refer out.
Guide · Freezer
Freezer alarm beeping
Identify which alarm (door, high temperature, power failure), silence it with the reset key, then fix the cause. Disabling alarms is not recommended because they protect food.
Guide · Freezer
Water under or around a freezer
Usual sources: melt water after a defrost or outage, a loose chest drain plug, sweating in humid rooms, or (on models with an ice maker) the water supply line. Frost-free uprights send defrost water to a drain pan where it evaporates.
Guide · Freezer
Freezer in a garage: hot or cold ambient problems
Standard freezers are rated for a limited room range (often about 50-55°F up to 110°F). Garage-ready models are rated wider; Danby lists 0°F to 110°F. Outside the rating, expect high-temp alarms, long run times or poor operation.
Fundamentals · Fundamentals
How to use a clamp meter on an appliance
A clamp meter shows whether a load is really working without breaking the circuit. The rule that trips most techs: clamp only one conductor. Clamping a whole cord reads near zero because the fields cancel.
Fundamentals · Fundamentals
Voltage-drop testing: finding a bad connection under load
A connection can pass an ohms or continuity test and still fail under load. Measuring voltage across a switch, connector or wire while current flows shows where power is being lost. A good closed contact drops almost nothing; a bad one drops a noticeable part of the supply.
Fundamentals · Fundamentals
Testing an outlet and an appliance power cord
Rule out the supply before opening the appliance. A plug-in tester screens wiring faults, a meter confirms voltage, and a continuity check confirms the cord. Damaged receptacles or panel problems are electrician work.
Fundamentals · Fundamentals
Ohm's law and power quick reference for appliance techs
Volts = amps × ohms, and watts = volts × amps. With the nameplate wattage and the supply voltage you can estimate what a heater should read in ohms and what it should draw in amps, then compare with your meter.
Fundamentals · Fundamentals
Reading a thermistor chart (NTC temperature sensors)
Most appliance temperature sensors are NTC thermistors: resistance falls as temperature rises, and the curve is not linear. Measure the sensor's real temperature, measure its resistance, and compare with the model's own chart. A 10 kΩ NTC reads about 10,000 Ω at 77 °F (25 °C), but curves differ by maker.
Fundamentals · Fundamentals
How to discharge and test a capacitor safely
Capacitors can hold a dangerous charge after power is removed. Kill power, verify 0 V, discharge through a resistor (not a screwdriver), confirm 0 V, then test capacitance against the label. Microwave high-voltage capacitors carry extra risk and need their own procedure.
Fundamentals · Fundamentals
ESD-safe handling of appliance control boards
Static from your body can damage board components at voltages you can't feel. Ground yourself, keep the new board in its bag until the moment of install, handle it by the edges and put the old board in the same bag for return.
Fundamentals · Fundamentals
Using a test cord or jumper safely for diagnosis (never as a fix)
Powering a load directly with a fused test cord, or briefly jumping a switch, can prove whether the load or the control is at fault. It is a short diagnostic step only. Never leave a jumper in place and never jump a safety device (thermal fuse, high-limit, door lock) to keep an appliance running.
Fundamentals · Fundamentals
How to find the model and serial number on any appliance
Every appliance has a rating plate with the model and serial number, but the location changes by type and brand. The full model number (including suffix) decides which tech sheet and parts apply. Manufacturers publish finder pages showing the label location.
Fundamentals · Fundamentals
Diagnosing intermittent faults
Intermittent problems are usually heat, vibration, moisture or a loose connection. Gather the history, read stored fault codes, reproduce the conditions and stress-test connections while monitoring. Don't replace a board on a guess.
Fundamentals · Fundamentals
How to use appliance service and diagnostic modes (general approach)
Most modern appliances have a service mode that shows stored codes, runs each load one at a time and displays sensor values. Entry sequences differ by model and are printed on the tech sheet. Use them to confirm a diagnosis before ordering parts.
Fundamentals · Fundamentals
Water pressure and flow test with a gauge and a bucket
Many fill complaints are supply problems. Check static pressure with a gauge, then check flow by timing a bucket fill. Typical washer instructions call for 20-120 psi at the inlet; below that, fill time stretches out. Compare flow with the spec on the model's installation instructions.
Fundamentals · Fundamentals
Measuring dryer vent restriction: airflow and back-pressure basics
A restricted vent is the most common cause of slow drying and blown thermal fuses, and failure to clean is the leading factor in residential dryer fires (USFA). Check the run against code and the manufacturer's limits, compare airflow at the termination, and measure back-pressure only against the manufacturer's spec.
Fundamentals · Fundamentals
Finding water leaks with paper towels and food dye
Water travels along frames and wires before it drips, so the puddle is rarely under the leak. Dry everything, lay paper towels at suspect points, and use a few drops of food coloring in the tub or tank to tell appliance water from supply or drain water.
Fundamentals · Fundamentals
Basic tool list for an appliance tech's truck
A starter kit that covers most residential appliance calls: test equipment first, then drivers and sockets, then specialty and safety gear. Rated test equipment and PPE are not where to save money.
Fundamentals · Fundamentals
How to document a service call (photos, readings, notes)
Good records make callbacks easier, support warranty and parts claims and protect you in disputes. Photograph the unit, labels and wiring before you touch anything, record actual readings with units, and note what you told the customer.
Fundamentals · Fundamentals
How to measure refrigerator and freezer temperatures properly
Air temperature swings every time the door opens, so measure a glass of water in the middle of the fresh-food section and between packages in the freezer, and give it hours to stabilize. Food-safety targets: fresh food at or below 40 °F (4 °C), freezer at 0 °F (-18 °C).
Fundamentals · Fundamentals
Hard water and scale: effects on appliances
Hard water carries dissolved calcium and magnesium that leave scale on heaters, valves, screens and spray arms. USGS classifies water as soft up to 60 mg/L (as calcium carbonate), moderately hard 61-120, hard 121-180 and very hard above 180. Knowing the local hardness helps explain repeat failures.
Fundamentals · Fundamentals
Appliance lifespan expectations (sourced estimates)
Published estimates are averages that assume normal use and maintenance. InterNACHI's chart lists dishwashers around 9 years, refrigerators 9-13 years and clothes dryers around 13 years; Consumer Reports-based figures cited by NerdWallet run higher for some types (e.g. dishwasher 12, top-freezer fridge 14, front-load washer about 9). Use ranges, not promises.
Fundamentals · Fundamentals
When to repair vs replace an appliance
A long-standing rule of thumb (older Consumer Reports advice) is to replace when the repair costs more than half the price of a new comparable unit. Consumer Reports now uses a calculator based on purchase price, age, repair cost and depreciation. Give the customer the numbers and let them decide.
Fundamentals · Fundamentals
Testing components with ohms and continuity: the basics
Most electrical parts can be checked power-off with ohms. Disconnect the part so other circuits don't skew the reading, compare with the tech sheet value, and always check from each terminal to the metal frame for a ground fault.
Fundamentals · Fundamentals
Verifying zero voltage before you touch: the live-dead-live check
Prove your tester works on a known live source, test the circuit you'll touch, then prove the tester again. OSHA requires de-energization to be verified with test equipment; the before-and-after check catches a dead meter or blown fuse that would otherwise read a false 0 V.
Fundamentals · Fundamentals
Gas smell or CO alarm on a service call: what to do
This is an emergency, not a repair. Stop work, get everyone out, don't operate switches or anything that can spark, and call 911 and the gas utility from a safe distance. Gas-side work is for a licensed gas technician.
Fundamentals · Fundamentals
EPA Section 608: what appliance techs can and cannot do
Without EPA 608 certification you can diagnose around the sealed system (fans, defrost, controls, start components, airflow) but you cannot open it, recover, recharge or dispose of refrigerant-containing equipment in a way that releases refrigerant. Type I covers small appliances (≤ 5 lb factory charge); Type II covers high-pressure systems; certification doesn't expire.
Guide · Furnace
Furnace runs no heat (blower only or nothing)
Start with the board LED code, then work the call path: thermostat, 24 V, safeties, inducer, ignition, flame proving. Most no-heat calls end at a filter, a flame sensor, a pressure switch issue or gas being off.
Guide · Furnace
Furnace short cycling (starts and stops quickly)
Short cycling is usually a safety opening mid-cycle (limit from low airflow, flame sensor dropping out, pressure switch opening) or a thermostat issue. Read the code and time the cycle.
Guide · Furnace
Igniter glows but burners never light
If the igniter glows and no flame appears, the problem is on the gas side (supply off, valve not opening, valve not receiving 24 V). You can confirm the gas shutoff is open and whether the board sends the valve signal; the valve and gas pressure are licensed-technician work.
Guide · Furnace
Burners light, then shut off after a few seconds (flame sensor)
The board must prove flame by flame rectification through the flame sensor. A dirty or oxidized sensor, poor ground or reversed polarity makes the board shut the gas off right after ignition.
Guide · Furnace
Pressure switch open / inducer problems
The pressure switch proves the inducer is moving combustion gases. It stays open when the vent/intake is blocked, the hose or port is plugged, the condensate trap backs up, or the inducer is weak.
Guide · Furnace
Limit trips / overheating (airflow)
The limit protects the heat exchanger from overheating. The fix is almost always airflow: filter, blower, ducts. Rollout switch trips are different and must be referred.
Guide · Furnace
Blower runs constantly
Check the thermostat fan setting first, then whether the board is holding the blower on for a safety (open limit) or a stuck relay. On electric furnaces a stuck sequencer can do the same.
Guide · Furnace
Condensate trap and drain problems (90%+ furnaces)
Condensing furnaces produce acidic condensate that drains through a trap. A clogged or unprimed trap, sagging drain line, frozen line or failed condensate pump causes water backup and pressure switch trips.
Guide · Furnace
Furnace won't turn on (no LED, nothing runs)
A dark board means no 120 V or no 24 V. Check the service switch, breaker, door switch, board fuse and transformer in that order.
Guide · Furnace
Noisy furnace (squeal, rattle, roar, boom)
Mechanical noises (squeal, grind, rattle) usually come from the blower or inducer and can be checked with power off. A loud boom at ignition or roaring flame is a gas/combustion problem that must be referred.
Guide · Garage Door Opener
Garage door reverses or will not close (safety sensors)
Nearly always the photo-eye safety sensors: blocked, misaligned, sun-blinded or miswired. Sensors must be repaired, never bypassed. If sensors are fine, look at force/limits and door binding.
Guide · Garage Door Opener
Opener runs or hums but the door does not move
Separate a disconnected trolley, a stripped gear/sprocket, a jammed trolley or a door problem (lock, broken spring). Door-side spring problems go to a door technician.
Guide · Garage Door Opener
Remote or keypad will not operate the opener
Check lock/vacation mode first, then the remote battery, then reprogram using the Learn/SET button. Short range is often radio interference from nearby LED bulbs.
Guide · Garage Door Opener
Opener light or LED blinking
Blinks are diagnostic. Count the pattern and look it up by brand: LiftMaster arrows/Learn LED, Genie powerhead LED, Overhead Door round/long LED.
Guide · Garage Door Opener
Door stops short or reverses at the floor (travel limits and force)
Usually travel limits or force need reprogramming, or the door is binding/out of balance. Test the door by hand first.
Guide · Garage Door Opener
Noisy garage door opener
Loose fasteners, poor lubrication, slack chain, worn drive gear or an unbalanced door. Separate opener noise from door noise by running each alone.
Guide · Garage Door Opener
myQ Wi-Fi opener offline or will not connect
myQ openers join only 2.4 GHz networks. Read the Wi-Fi LED, power-cycle opener and router, clear Wi-Fi and rerun setup in the app.
Guide · Garage Door Opener
Wall button not working (or door opens by itself)
A shorted or reversed wall-control wire is the usual cause, often from a staple. Phantom operation is commonly a shorted wall button or a stuck remote.
Guide · Garage Door Opener
Opener beeping (battery backup)
Beeps come from the battery backup: running on battery, low battery or a worn-out battery. Replace the 12 V battery when the LED is solid red.
Guide · Garbage Disposal
Garbage disposal hums but won't turn (jammed)
A humming disposal almost always has a jammed turntable: a hard object or packed waste is stopping the motor. Free the plate with the hex wrench from below (or a wrench on the impellers from above), clear the debris, then reset the overload. Never put a hand in the grinding chamber.
Guide · Garbage Disposal
Garbage disposal dead: no hum, no power
Work from the simplest cause: the motor overload (red reset), then the breaker and outlet, then the switch type (wall switch, air switch, batch-feed stopper switch). Replace the disposal only after power is proven at the outlet and the reset does nothing.
Guide · Garbage Disposal
Garbage disposal leaking: top, middle or bottom
Find the exact leak point with the paper-towel test. Top = sink flange seal or mounting; middle = dishwasher inlet or discharge elbow; bottom = water inside the housing. Flange and connection leaks are fixable; water from the motor housing itself usually means internal seal failure and replacement.
Guide · Garbage Disposal
Sink with disposal drains slowly or backs up
If the disposal spins and the water swirls but will not go down, the blockage is in the trap or drain line, not the disposal. Clean the baffle and chamber, plunge carefully, then open the trap. Do not use chemical drain cleaners in a disposal.
Guide · Garbage Disposal
Garbage disposal noisy: grinding, rattling or vibration
A foreign object in the chamber is the most common cause of loud metallic noise. Loose mounting, a worn cushion mount and worn bearings cause vibration and rumble. Odor and visible waste at the flange after running are also signs of a partial jam.
Guide · Garbage Disposal
Dishwasher won't drain or drains into the sink after a new disposal install
New disposals ship with a plastic knockout plug sealing the dishwasher inlet. If the dishwasher hose was connected without knocking it out, the dishwasher cannot drain. Knock the plug out and remove it from the chamber; also check the hose loop or air gap and the 7/8 in inlet connection.
Guide · Wine Cooler
Thermoelectric wine cooler not cooling (fans run, cabinet near room temperature)
Thermoelectric coolers move heat with a solid-state Peltier module and two heat-sink fans, so they can only pull the cabinet a limited amount below room air. Rule out a hot room, blocked airflow and dusty fins before condemning the module, its fans or the DC power supply.
Guide · Wine Cooler
Dual-zone wine cooler: one zone warm, the other fine
When one zone of a dual-zone cooler works, the compressor or main cooling is usually alive. Focus on what each zone has on its own: its sensor, its fan, its air path or damper, its door seal and its section of the control.
Guide · Trash Compactor
Trash compactor motor runs but the ram does not move
If the motor turns freely, the fault is in the drive train between the motor and the ram: drive chain or belt, sprockets/gears, or the plastic power nuts that ride the power screws. A broken directional/limit switch can also leave the screws turning the wrong way or not at all.
Guide · Sump / Well Pump
Sump pump trips the GFCI or breaker
A GFCI that trips with a sump pump is usually detecting real current leakage from a pump motor taking on water, a damaged cord or splice, or another load on the same circuit. Isolate the pump from the circuit before blaming the GFCI, and never bypass the protection on a pump in water.
Guide · Sump / Well Pump
Sewer or musty smell from the sump pit
A clean sump pit should not smell like sewage. Most odors come from a pit that has dried out and no longer seals the drain tile lines, stagnant water, organic buildup, or nearby plumbing traps that have dried or been siphoned. A strong, persistent sewage smell can mean a leaking sewer line near the pit.
Guide · Sump / Well Pump
Sump pump keeps cycling when it has not rained
The most common cause is water returning from the discharge pipe through a failed or missing check valve, so the pump moves the same water again and again. Other causes are a small basin, a float set too close, a high water table or a leak feeding the pit.
Guide · Sump / Well Pump
Well pump runs nonstop and never reaches cut-out pressure
The pump cannot build enough pressure to open the pressure switch, either because water is escaping (leak, running fixture, failed check valve), the pump is worn or has lost prime, the well cannot keep up, or the cut-out is set above what the pump can make. Running dry can ruin the pump, so act quickly.
Guide · Sump / Well Pump
Air spitting or sputtering from faucets on a well system
Air in a well system usually enters because the pump is drawing down the well (low water level) or because a leak or failed check valve lets the line drain back and suck air in when the pump stops. A failed pressure-tank bladder can also send air into the lines.
Guide · Sump / Well Pump
Well pump trips its breaker
Breaker trips point to a short or overload: damaged drop cable in the well, a seized or failing motor, bad start components in the control box (3-wire submersibles), a pressure switch with burnt contacts, or a frozen line that stalls the pump. Pulling the pump is contractor work, but the topside checks narrow it down.
Guide · Sump / Well Pump
Well system pressure slowly getting weaker
A slow decline is most often a filter or treatment unit clogging up between the tank and the house. Next suspects are the pressure switch settings or a clogged switch port, the tank air charge, and finally a worn pump or falling water level.
Guide · Water Softener
Water tastes salty after the softener regenerates
Softened water should not taste salty. A salty taste means brine was not fully drawn and rinsed out of the resin: clogged injector or brine line, restricted drain line or drain flow control, low supply pressure during regeneration, or a regeneration interrupted by a power or pressure loss.
Guide · Water Softener
Water softener uses too much salt or regenerates every night
Excess salt use is almost always a settings problem: hardness programmed too high, a timer set to regenerate every day, wrong capacity or salt dose for the household, or a lost program. Mechanical causes include a leaking brine valve, iron-fouled resin and a brine tank that overfills.
Guide · Water Softener
Softener regenerates at the wrong time (often after a power outage)
Most timer and metered controls schedule regeneration by the clock, typically in the middle of the night. After an outage the clock can be wrong or reset, so regenerations happen when people are using water. The softener still softens, but the clock and settings need checking.
Guide · Water Softener
Orange/rust stains even with a working softener
Softeners handle hardness well but have limited ability to remove iron, especially iron that has already oxidized. Iron coats the resin, cuts capacity and passes through to stain fixtures. Test the water before recommending an iron filter or resin cleaning.
Guide · Ice Maker
Countertop ice maker shows 'Add Water' with water in the reservoir
These units detect water with a float, probe or wire sensor in the reservoir and a small pump that lifts water to the tray. Scale on the sensor, a blocked reservoir screen, a stuck float, very pure water or a weak pump can all trigger a false Add Water.
Guide · Ice Maker
Undercounter ice maker: ice slab will not release or sticks on the cutting grid
Grid-cutter (slab) ice makers freeze a sheet, release it during harvest and let a heated wire grid cut it into cubes. Most release problems come from an unlevel cabinet, scale on the evaporator plate, or a cutting grid that is unplugged or not heating. Harvest switches and probes are next.
Guide · Freezer
Freezer noisy: buzzing, rattling or scraping
Find the source first: condenser fan and coils at the bottom/back, evaporator fan inside (frost-free uprights only), compressor mounts, or the cabinet itself touching something. Many noises are fixed by cleaning, levelling or clearing ice from the fan.
Guide · Garbage Disposal
Batch-feed disposal will not start with the stopper in place
Batch-feed disposals run only when the stopper closes a switch on the unit, either a mechanical switch pushed by a cam on the stopper or a magnetic reed switch on older models. Check the reset button and power first, then the stopper cam/magnet and the start switch.
Guide · Garbage Disposal
Disposal runs but grinds slowly or leaves chunks
A running motor with poor grinding points to a partial jam, impellers (lugs) stuck in place, packed buildup around the grind ring, too little water flow, or worn grind components. On older units a worn grind ring often means replacing the disposal.
Guide · Thermostat
Indoor fan won't turn off from the thermostat
Start at the thermostat: fan set to ON instead of AUTO, or a setpoint the system can never reach. If the thermostat is right, the cause is in the equipment: a stuck fan relay, a limit switch keeping the blower on, a shorted G wire or a control board fault.
Guide · Thermostat
Thermostat shows WAIT or flashing 'Cool On'
Most thermostats hold the compressor off for a few minutes after it stops or after power returns, to prevent short cycling. That delay is normal. If the message lasts well past the delay or the system never starts, check mode, breakers, filter-related lockouts and wiring.
Guide · Thermostat
Thermostat setpoint changes by itself
Most 'ghost' changes come from features, not faults: a program schedule resuming after a temporary hold, learning schedules, eco/away modes, utility demand-response events, or another person or app. Check the thermostat history before replacing it.
Guide · Furnace
Burning smell when the heat first comes on
Dust settled on the heat exchanger or electric heat strips burns off at the first firing and fades within a few hours. A smell that lingers, or smells like plastic, rubber, hot wiring or gas, is not normal and needs diagnosis.
Guide · Furnace
Whole-house humidifier not adding moisture
Bypass and fan-powered humidifiers need water, airflow and a call from the humidistat. Check the season damper, water valve, scaled water panel and humidistat before testing the 24 V solenoid valve.
Guide · Furnace
Whole-house humidifier leaking or running nonstop
Leaks come from a blocked drain line, loose tubing, or a scaled distribution tray. Constant water flow or too much humidity points to a setpoint that is too high, a humidistat or sensing problem, or a stuck-open valve.
Guide · Furnace
Furnace blowing cold air on a heat call
The common causes are a fan set to ON, a dirty filter tripping the high limit so the burners stop while the blower runs, a full condensate drain on a high-efficiency furnace, or an ignition lockout. Gas valve and burner work is blocked; stop at diagnosis and refer.
Guide · Garage Door Opener
Garage door won't move with the opener after the red release cord was pulled
The emergency release disconnects the door arm from the trolley. Re-engaging it is usually a matter of setting the release back to its connected position and running the opener so the trolley catches the carriage. First confirm the door is balanced; a heavy door means a spring problem, which is blocked work.
Guide · Garage Door Opener
Opener strains or door won't lift: broken spring (diagnose and refer)
Springs carry the door weight; the opener only guides it. A broken torsion or extension spring makes the door too heavy, and the opener strains, reverses or strips gears. Spring and cable work is blocked: confirm the symptom safely and refer to a garage-door technician.
Guide · Garage Door Opener
Garage opener light stays on, or will not light
A light that stays on is usually a feature (light button, motion detection, safety-light on beam break) or a door control/wiring fault; Chamberlain gives a test that separates the door control from the logic board. A dead light is usually the bulb, its type, or the socket.
Guide · Refrigerator
Refrigerator ice maker overflowing (ice block in the bin)
Overflow usually means water entering when it should not: an inlet valve that seeps closed because of low pressure or debris, a fill tube that froze and diverts water, or a cracked fill tube. A tray that is not level or a misreading ice maker can also overfill.
Guide · Refrigerator
Refrigerator water dispenser keeps dripping after use
A few drops right after dispensing is normal. Longer dripping is usually trapped air in the lines after a filter change or door removal, which pushes water out as it expands. If purging does not help, check filter seating, levelling and the inlet valve.
Guide · Washer
Washer shows a code, stays locked or won't start after a power outage
Outages and surges can leave the control in a confused state mid-cycle. A full power reset clears most cases. If the code returns, read it and diagnose the part it names (lock, pump, valve); if the control is dead or erratic after a surge, the main control may be damaged.
Guide · Range / Oven
Oven takes too long to preheat
First confirm it is really slow: many ovens take around 10-15 minutes to reach 350°F, longer with large cavities or convection preheat. On electric ovens a partly failed bake element or a dead broil element (used during preheat on many models) slows preheat. On gas ovens a weak igniter that glows but draws too little current opens the gas valve late or not fully.
Guide · Air Conditioner
Central AC shut off by the condensate float switch
Float switches cut the cooling circuit when condensate backs up, usually from an algae or dust clog in the drain line or a failed condensate pump. Clear the drain, let the switch dry/reset, and find out why it backed up. Never bypass the switch.
Guide · Air Conditioner
Central AC won't come back after a power outage or breaker trip
After power returns, thermostats and some outdoor units hold off the compressor for a few minutes. If nothing starts after that, check the thermostat, both breakers, the outdoor disconnect, the float switch and the low-voltage fuse before suspecting parts damaged by a surge.
Guide · Water Heater
Rusty or brown water from hot taps only
When only the hot side is discolored, the tank is the likely source: a depleted anode rod that let the tank start corroding, rusty sediment, or (on wells) iron/manganese or iron bacteria. Check the anode before condemning the tank, but rust from an old tank lining usually means replacement.
Guide · Dishwasher
Dishwasher upper rack drops, tilts or falls off the track
Upper racks ride on rails with end stops and, on adjustable racks, a height adjuster on each side. Broken adjuster latches, missing wheels, worn end stops or a cracked rail cause most sagging and fall-off complaints. These are snap-in parts matched to the model number.
Guide · Ice Maker
Undercounter ice maker not making ice
Check power, water supply and pressure, drain (pump models stop when they cannot drain), bin sensor, cleaning status, condenser and room temperature. Scale is the most common cause on older machines.
Guide · Ice Maker
Small, thin, hollow or cloudy cubes
Small or thin cubes usually mean not enough water: low pressure, a clogged filter or inlet screen, or water leaking out of the pan (loose drain cap, check valve leak-by). Cloudy ice usually means scale. In bins that are insulated but not refrigerated, cubes naturally shrink and clump over time.
Guide · Ice Maker
Ice maker leaking
Check supply connections, drain hose alignment and clamps, drain cap, level and (if fitted) the drain pump kit connections. Some dripping from the cutter grid into the bin during harvest is normal on clear-ice units.
Guide · Ice Maker
GE Opal nugget ice maker not making ice / descaling
Most no-ice Opal calls are water starvation (low reservoir, side-tank hose, clogged filter, air) or scale. Follow GE's clean/descale procedure with intervals based on water hardness. Continuous grinding is not normal and goes to Opal support.
Guide · Ice Maker
Ice tastes or smells bad
Common causes: old filter, food stored in the bin, dirty bin, and mineral scale. Replace the filter, keep only ice in the bin, wash the bin and clean/sanitize the machine.
Guide · Ice Maker
Ice maker drain pump problems
Pump models are used when there is no gravity drain (e.g. draining to a sink). They need correct hose routing within the stated rise/run limits and tight connections. A pump that cannot discharge can stop production or cause leaks.
Guide · Ice Maker
Full-bin sensor: overfilling or stopping too early
Bin controls are infrared/optical sensors (countertop, Opal), thermostatic bulbs (Hoshizaki) or thermistor sensors. Dirty, blocked, loose or misplaced sensors cause over- or under-production.
Install · Dishwasher
Dishwasher install: water, drain loop or air gap, power and mounting
A built-in dishwasher needs four things done right: a hot-water supply with its own shutoff, a drain that cannot siphon back (high loop or air gap, as local code requires), the correct electrical connection for that model, and secure mounting to the counter or cabinet sides. Most callbacks come from a kinked drain hose, a skipped high loop, or a unit that was never anchored.
Install · Dishwasher
Dishwasher electrical: hardwired whip vs plug-in cord kit
Dishwashers arrive either set up for a hardwired connection at their own junction box or for a cord kit, and the model instructions say which is allowed. Hardwiring and any change to the circuit are electrical work and may need a licensed electrician and permit. The handyman scope is usually reconnecting an existing, code-compliant circuit the same way it was.
Install · Dishwasher
Dishwasher replacement: swapping an old unit (disposal knockout, reused connections)
A swap is faster than a new install but hides traps: old supply lines and fittings that should be replaced, a disposal inlet that still has its knockout plug if the disposal is also new, and an old drain path with no high loop. Treat every connection as new.
Install · Range / Oven
Range install and anti-tip bracket
Every freestanding and slide-in range must be secured with the anti-tip bracket that ships with it, fixed to the wall or floor and engaged by the rear foot. Electric ranges connect with a cord to a 240 V receptacle; gas connections are for a licensed gas installer.
Install · Range / Oven
Electric range cord: 3-wire vs 4-wire connection
The cord must match the receptacle: older homes may have a 3-prong 240 V receptacle (neutral and ground shared) while newer installs use 4-prong (separate neutral and ground). The range terminal block has a neutral-to-frame link that stays for 3-wire and is removed (with the green wire to the frame) for 4-wire. Follow the model diagram exactly.
Install · Range / Oven
Cooktop drop-in install (electric or induction; gas referred)
Drop-in cooktops depend on the cut-out size, clearances to cabinets above and the correct hardwired connection. Check the new cut-out dimensions before buying: a cut-out that is too big cannot be fixed easily in stone.
Install · Range / Oven
Wall oven install: cut-out, support platform and conduit connection
Wall ovens are heavy and hardwired. The cabinet needs the right cut-out and a support platform rated for the oven weight, and the flexible conduit connects to an approved junction box with a strain relief clamp. Manufacturers do not allow a plug and receptacle on these products.
Install · Microwave
Over-the-range microwave install: wall plate, top bolts and venting
An OTR microwave hangs on a wall plate anchored into at least one stud and is bolted up through the cabinet above. It ships set for one vent mode (often recirculating) and must be converted for outside venting through the wall or roof. Use the paper templates from the box; hole positions differ between brands.
Install · Range Hood
Range hood ducting: duct size, route, termination and makeup air
Hood performance depends more on the duct than the blower. Use the duct size the hood requires (never smaller), smooth metal duct, as few elbows as possible, and a proper wall or roof cap with a damper. Larger hoods can trigger a makeup-air requirement under local code (commonly when the hood can exhaust more than 400 CFM in homes with certain fuel-burning appliances).
Install · Refrigerator
Refrigerator water line and ice maker hookup
Run a 1/4 in supply (copper or a PEX kit made for refrigerators) from an accessible shutoff to the fridge inlet, leave a service loop so the fridge can be pulled out, flush the line before connecting and flush the new filter afterward. Avoid self-piercing saddle valves where code or the manufacturer discourages them.
Install · Refrigerator
Reversing refrigerator doors (general method)
Many top-freezer and compact refrigerators allow door reversal by moving hinges, the door stop and handles to the other side. Some models (including some stainless models) are not reversible, and French-door or side-by-side models generally are not. Check the instructions first.
Install · Refrigerator
Refrigerator leveling and door alignment
Most refrigerators should be level side to side and tilted slightly back so the doors swing closed. French doors have a separate height adjustment for door alignment. Level after any door reversal, panel install or water connection.
Install · Washer
Washer install: hoses, shipping bolts, standpipe and leveling
The key steps are removing the shipping hardware, using new fill hoses, setting the drain hose correctly in a standpipe of the right height without sealing it, and leveling. Leftover shipping bolts cause violent shaking on the first spin.
Install · Washer
Stacking a washer and dryer with a stacking kit
Only stack front-load pairs the manufacturer lists as stackable, using that brand's kit for those models. The kit brackets attach to the washer top and hold the dryer feet; some kits also need a wall anchor. Lifting the dryer is a two-person job.
Install · Dryer
Dryer vent installation: materials, length, elbows and termination
Use 4 in rigid or semi-rigid metal duct with a smooth interior, keep the run within the code or manufacturer limit (the model code limit is 35 ft, reduced for each elbow, unless the dryer maker allows longer), and terminate outside with a backdraft damper and no screen. Never vent into an attic, crawl space or wall cavity.
Install · Dryer
Electric dryer cord change (3-wire to 4-wire or reverse)
Match the cord to the receptacle. With a 3-wire cord the neutral-to-cabinet ground strap (or green screw link) stays in place. With a 4-wire cord the strap is removed, the green wire goes to the cabinet ground screw and the white to the center neutral terminal only.
Install · Dryer
Gas dryer connection (BLOCKED: refer to a licensed gas installer)
Connecting, disconnecting or leak-testing a gas line is licensed gas work in most US jurisdictions. A handyman may prepare the space, the 120 V outlet and the vent, then the gas connection and leak test go to a licensed gas installer or plumber.
Install · Garbage Disposal
Garbage disposal install and replacement
A disposal hangs on a sink-flange mount, connects to the trap and, if present, the dishwasher drain. Replacing with the same brand family often allows reuse of the existing mount; otherwise install the new flange. Knock out the dishwasher inlet plug only if a dishwasher will connect.
Install · Water Heater
Electric water heater replacement (permit; fill before power)
Many jurisdictions require a permit and inspection for water heater replacement, and some limit who may do it. The critical steps are a new T&P valve and correct discharge pipe, proper water connections, and filling the tank completely before power goes on: powering an empty tank burns out the element almost immediately.
Install · Water Heater
Gas water heater replacement (BLOCKED: refer to a licensed plumber / gas installer)
Replacing a gas water heater involves the gas connection, flue venting and combustion air, which are licensed work. The handyman role is to assess, take immediate safety action and refer.
Install · Water Heater
Thermal expansion tank install
An expansion tank absorbs the water that expands as the heater warms it. Set the tank air pre-charge to match the home static water pressure (or the PRV setting) before installing, then mount it on the cold supply to the heater and support its weight.
Install · Sump / Well Pump
Sump pump replacement
Swap the pump for one of similar or better capacity, reuse or replace the check valve, drill the small air-relief (vent) hole in the discharge pipe below the check valve when the pump instructions call for it, and plug into a GFCI receptacle without an extension cord. Test with a bucket of water.
Install · Thermostat
Thermostat replacement (low-voltage)
Most central HVAC thermostats are 24 V. Kill power to the HVAC system, photograph and label the existing wires, and confirm compatibility (C wire for most smart thermostats). Line-voltage (120/240 V) thermostats for baseboard heat are a different product and need a matching line-voltage model.
Install · Air Conditioner
Mini-split install overview: mounting and electrical prep only (line set BLOCKED)
The handyman scope is limited to the indoor wall plate, the wall penetration, the outdoor pad or bracket and coordinating electrical work. Line-set connection, vacuum, refrigerant release or charging are EPA 608 work and BLOCKED; the outdoor disconnect and circuit are for a licensed electrician.
Install · Air Conditioner
Window air conditioner install and support bracket
Secure the unit so it cannot fall, give it the slight outward tilt the manual specifies (some models have a sloped base pan and need none), seal the side panels, and plug directly into a suitable outlet. Larger or heavier units should have an exterior support bracket.
Install · Garage Door Opener
Garage door opener install (spring work BLOCKED)
An opener only moves a door that is already balanced by its springs. Check balance first, mount the rail and header bracket per the manual, place the safety reversing sensors no higher than 6 in above the floor and aligned, and test the auto-reverse. Spring and cable work is BLOCKED: refer to a garage door technician.
Install · Water Softener
Water softener install with bypass valve
Install the softener after the main shutoff (and usually before the water heater) with a bypass valve so water can run while the unit is serviced. Run the valve drain to an approved drain with an air gap, run the brine-tank overflow separately by gravity, and never join the two.
Install · Water Softener
Reverse osmosis (RO) under-sink install
An RO system needs a cold-water feed, a drain saddle on the sink drain above the trap (away from the disposal), a dedicated faucet (often an air-gap faucet where code requires) and the storage tank. Flush the system per the instructions before drinking.
Install · Wine Cooler
Built-in wine cooler: front venting and clearances
Only front-venting units are designed to be built in. Rear-venting (freestanding) units need open space around them and overheat when boxed in. Keep the front grille or kickplate vents fully open and follow the opening and clearance dimensions in the installation instructions.
Install · Trash Compactor
Trash compactor undercounter install
Undercounter compactors slide into a standard opening and plug into a grounded 120 V outlet placed beside the unit. Check the opening height so the top clears the counter, level the unit and secure it as the instructions require.
Install · Ice Maker
Undercounter ice maker install: water, drain (gravity or pump) and venting
Undercounter ice makers need a cold-water line with shutoff and a way to drain melt water: gravity to a floor drain or standpipe below the unit, or a drain pump model/kit when the drain is higher. Keep the front grille clear and level the unit carefully so water drains.
Install · TV
TV wall mounting: studs, VESA, cable routing and in-wall power
Choose a mount that matches the TV VESA pattern and weight, anchor it into studs (or masonry anchors on brick/concrete), and hide cables only with in-wall-rated cable or a recessed power kit. Running the TV power cord itself inside the wall is not an accepted practice under the electrical code: use a listed in-wall power kit or a new outlet installed by an electrician where required.
Install · Washer
Post-install checklist for water-connected appliances (leak, level, test cycle)
Most install callbacks are a slow leak, an unlevel unit or a drain that siphons. A short, repeatable checklist before leaving the job catches them.
Guide · Air Conditioner
Central AC: indoor blower runs but outdoor unit won't start (24 V circuit check)
Work the 24 V circuit from the thermostat to the contactor coil. A tripped float switch, damaged outdoor thermostat cable or an open disconnect are far more common than a dead compressor.
Guide · Air Conditioner
Heat pump outdoor coil iced over (not defrosting)
Light frost that clears every hour or so is normal. A solid block of ice means defrost isn't starting or finishing. Check outdoor fan, defrost sensor and board with a forced defrost before suspecting refrigerant.
Guide · Air Conditioner
Heat pump blows cold in heat mode (or heats in cool mode)
The reversing valve is in the wrong position. Check the thermostat O/B setting first, then 24 V at the solenoid coil, then the coil itself. A valve that won't shift with a good energized coil is sealed-system work.
Guide · Air Conditioner
Portable AC shows water-full code or keeps filling
In humid weather or dry mode, a portable can collect water faster than it evaporates it. Drain and set up a continuous drain first; a code with an empty tank points to the float switch or internal pump.
Guide · Air Conditioner
Mini-split communication error: interconnect wiring check
Most communication faults are wiring: swapped terminals, loose screws, splices or damaged cable, often after a new install or a storm. Check power, then terminations at both ends, then the data signal, before replacing a board.
Guide · Dishwasher
DishDrawer F1: water in base / flood
F1 means the flood sensor found water. Separate foam problems from real leaks before taking anything apart. Real leaks on older units usually come from cracked drain hoses or a lid that is not sealing.
Guide · Refrigerator
Compact / mini-fridge not cooling
First decide whether it is a compressor or thermoelectric unit. Thermoelectric units are limited by room temperature. On compressor units, the start relay/overload is the cheap fix and sealed-system faults usually mean replacement.
Guide · Refrigerator
Premium built-in refrigerator: one section warm (Sub-Zero vs. Monogram logic)
Start by knowing the architecture. Sub-Zero built-ins have two separate sealed systems, so a warm section means a fault in that section's own fan, defrost, sensor or system. Monogram built-ins share one freezer evaporator and feed fresh food through a damper, so a warm fresh-food side with a cold freezer points at the damper, airflow or an iced return passage.
Guide · Range / Oven
Pro-style range or rangetop: burners click continuously (Wolf, Viking, Thermador)
On pro-style sealed burners the spark module sparks until it senses flame. Moisture, a mis-seated cap, a stuck knob switch, reversed polarity or a poor ground keep it sparking. Normal behaviors (ExtraLow re-ignition on Thermador, a spark or two after power-up) must be ruled out first. Gas-side work is never part of this guide.
Guide · Dryer
Speed Queen dryer runs but does not heat (electric)
Most cases are a blown thermal fuse and/or failed high-limit caused by a restricted vent. Clear the vent before replacing parts, then test the fuse, high-limit and element.
Guide · Washer
Haier portable washer will not fill or drain
Portable washers depend on the kitchen faucet and sink. Check the adapter, aerator, hose routing and pump filter before replacing parts.
Guide · Dishwasher
Dishwasher not heating water
Confirm the supply water is hot first, then test the heater (or Bosch heat pump heater), the high-limit and the thermistor. If all test good, suspect the heater relay on the control.
Guide · Dishwasher
Dishwasher cycle runs too long or stalls
Most long cycles are the control waiting for heat (cool supply, bad heater or thermistor) or a soil sensor reading dirty water. Check water temperature, then clean the turbidity sensor, then test thermistor and heater.
Guide · Dishwasher
Dishwasher trips the breaker or GFCI
A GFCI trip means current leaking to ground, often from a cracked heating element, water on heater terminals, or a leaking pump. Isolate loads one at a time with power off.
Guide · Dishwasher
Dishwasher smells bad
Usually food and grease in a manual-clean filter, spray arms or the tub bottom, or standing water from a slow drain. Clean, then fix drainage; check the disposer too.
Guide · Dishwasher
Cloudy glasses or white film
Tell hard-water film from etching with a vinegar soak: film comes off, etching does not. Film is fixed with rinse aid, correct detergent dose and softening; etching is permanent and made worse by soft water, too much detergent and very hot cycles.
Guide · Dryer
Dryer trips the breaker
Tripping when heat starts usually points to a heater element shorted to its housing; tripping at start points to the motor or wiring; tripping at random may be a weak breaker or loose connection. Rule out the terminal block and cord first.
Guide · Dryer
Burnt power cord or terminal block
Loose cord screws heat up under the dryer's high current and burn the terminal block. The fix is a new cord and block installed exactly per the install instructions for 3-wire or 4-wire.
Guide · Dryer
Heat-pump (ventless) dryer drying poorly
Heat-pump dryers are slower than vented dryers by design. Real faults are usually clogged lint or condenser filters, a blocked drain path, or a cold room. The refrigerant circuit is sealed: diagnosis only.
Guide · Dryer
Dryer door won't stay closed or dryer stops when bumped
A worn strike or catch, a cracked plastic strike, or a weak door switch actuator makes the control see the door open. Inspect mechanicals before replacing the switch.
Guide · Microwave
Microwave shuts off by itself during cooking
Mid-cook shut-downs usually mean a thermal cutout is opening because the cooling fan failed or the vents are blocked, or a marginal door switch is opening. Check airflow and installation first, then the fan, cutouts and switches with the HV capacitor discharged.
Guide · Microwave
Microwave heats slowly or weakly
Confirm with a water test on High. Then rule out a low power setting and low line voltage, since a small voltage drop cuts output a lot. An aging magnetron is the most common part cause; poor connections and a failing thermal protector also show up.
Guide · Microwave
Over-the-range microwave vents poorly (smoke and steam not captured)
Most cases are installation: the blower was never rotated from the factory recirculate setup, the damper is taped or stuck, or the duct is the wrong size, crushed or too long. Clogged filters and a grease-packed blower wheel are next.
Guide · Microwave
Microwave drawer will not open, close or stay closed
Rule out an obstruction, an overloaded drawer, the control lock and a power interruption, then reset at the breaker. Persistent faults point to the position/sensing switch, drawer motor, slides or the control; check for oversized mounting screws on new installs.
Guide · Microwave
Microwave starts by itself or will not stop
A microwave that heats on its own is a fire hazard: unplug it and do not use it. The usual cause is a stuck relay or shorted triac on the control. On OTR units, a fan that starts by itself is often normal heat protection, and a light that stays on can be moisture.
Guide · Range / Oven
Gas cooktop igniters click non-stop
The spark module only fires when a burner spark switch feeds it power, so constant clicking almost always means a wet or shorted switch. If clicking continues with the switches disconnected, the module is stuck. Clicking only after the burner lights points to the electrode, burner cap or ground/polarity instead.
Guide · Range / Oven
Gas cooktop burner won't spark or won't light
No click at any burner points to the spark module or loss of 120 V. No click at one burner is that burner's switch or electrode lead. Clicks but no flame is usually a misplaced cap, a clogged ignition port or a spark that grounds out before reaching the port. Any problem with gas flow itself is blocked: refer to a licensed gas tech.
Guide · Range / Oven
Self-clean won't start or door won't lock
The control will not heat for self-clean until the lock switch confirms the door is locked. Check that the door closes fully, then whether the lock motor moves at all: no movement points to the motor or the control output; movement without confirmation points to the switch, latch binding or wiring.
Guide · Range / Oven
Convection fan not running
Check the blade spins freely, then the motor winding, then whether the control sends 120 V. Bake and broil still work without the fan, so customers often notice only uneven results.
Guide · Range / Oven
Induction zone shuts off or shows overheat error
Induction electronics depend on the cooling fan. Rule out blocked vents and normal power limiting first, then check the fan. A repeat driver code with a working fan points to the generator board, which is replaced as an assembly.
Guide · Refrigerator
Top-mount refrigerator: defrost timer and cold control check
On conventional top-mounts, a mechanical defrost timer and a cold control decide when the unit cools or defrosts. Advancing the timer by hand tells you in minutes whether the timer, the defrost parts or the cold control is at fault.
Guide · Refrigerator
Refrigerator condenser fan not running
The condenser fan pulls room air over the condenser and compressor. A dirty coil or a seized or failed fan makes the compressor run hot and long and can trip its overload. Clean first, then check the fan and the supply to it.
Guide · Refrigerator
Refrigerator dead: no lights, no display, nothing running
Work from the outlet inward: supply, cord, door/display harness, then the boards. Many 'dead display' calls on French-door and side-by-side units are harness faults at the door hinge, not failed boards.
Guide · Refrigerator
Refrigerator sweating: condensation outside or inside the cabinet
Warm, humid air meeting a cold surface causes condensation. Look at door seals, door alignment, room humidity and settings first. Then check the anti-condensation heaters where fitted, such as the French-door center flipper (mullion) heater or the cabinet face heaters.
Guide · TV
Soundbar or receiver has no audio over HDMI ARC/eARC
Almost always a settings or port problem: CEC off, ARC/eARC not enabled, soundbar on a non-ARC port, or the TV's audio format set to something the bar can't decode. Work through settings before suspecting hardware.
Guide · TV
OLED image retention or burn-in
Short-term retention usually clears on its own once the TV's automatic compensation runs at power-off. One manual refresh is the next step; if the ghost survives, it is permanent panel wear and the fix is a panel.
Guide · TV
LED backlight strip replacement (direct-lit LCD TVs)
On direct-lit sets the strips sit behind the LCD and optical sheets. The job is mostly careful handling: lift the panel by its frame, keep the sheets in order, replace the whole strip set by part number and test before closing.
Guide · TV
Firmware update or recovery from a USB drive (Samsung, LG)
Samsung and LG let you load the model's update file from a USB stick. The format and folder rules are strict; most failures are a wrong file, wrong folder or wrong format.
Guide · TV
Wall-mounted TV loose, sagging or unsafe
Check fastening into structure, mount rating versus TV weight, and the TV-side screws. Most failures are drywall-only anchoring or wrong VESA screws.
Guide · Washer
LG LE code: testing the hall sensor and stator
LE means the board drove the motor but did not see rotation. Check the harness, then test the hall sensor (about 10 kΩ per channel and a pulsing signal), then the stator windings, before condemning the board.
Guide · Washer
Whirlpool/Maytag VMW top-load: F7E5 / shifter or drive fault
The control did not see the shifter or basket move as expected. Check mechanics and wiring first; the shifter (with its internal position sensor) is the most common replacement.
Guide · Washer
Classic Whirlpool/Kenmore direct-drive: agitates but won't spin
Check the lid switch first, then watch the clutch drum in spin to split the problem between the coupler/gearcase and the clutch/drive block.
Guide · Washer
Front-load roaring or grinding in spin (bearings, rotor, spider)
Rising roar with speed usually means failed rear tub bearings, often after the seal leaks. Rule out a loose rotor or foreign object first, because a bearing job is a major repair that may cost more than the washer is worth.
Guide · Washer
Frigidaire front-load: reading codes and running diagnostic tests
Codes can be read by holding two buttons; the full diagnostic mode is stepped with the program knob.
Guide · Microwave
Microwave has display/clock but won't start
Rule out user settings first (control lock, demo mode, Start not pressed, shipping spacer). If those are fine, the control is not seeing a closed door or is not driving its relays: door switches, latch, or control board.
Guide · Microwave
Microwave door won't close, won't open or latch broken
Obstructions, an unlevel install or soil on the contact area cause most closing problems. Broken latch hooks, door release levers or switch actuators need parts and HV-safe disassembly.
Guide · Microwave
Microwave trips the house breaker or GFCI
Separate a supply problem (shared or undersized circuit, GFCI nuisance trips) from an internal short. Internal shorts in the HV section usually blow the internal fuse; a trip on start can also come from a shorted HV component.
Guide · Microwave
Microwave turntable clicking, grinding or jerking
A turntable that reverses direction between cycles is normal. Clicking and grinding usually come from a dirty or damaged roller ring, a worn drive coupler or a tray not seated on the coupler; a failing motor is last.
Guide · Microwave
Sensor cook / auto programs not working
Sensor programs depend on a humidity or vapor sensor and a correct load. Most failures are usage (tight covers, tiny loads, hot cavity) or grease on the sensor; a failed sensor or wiring shows a code.
Guide · Microwave
Microwave light stays on (cooktop or cavity light)
Cooktop light: wrong bulb type or a light timer setting are common causes. Cavity light on with door closed points to a door switch not releasing or a stuck relay on the control board.
Guide · Microwave
Microwave hums loudly (with weak or no heat)
A loud hum is usually the HV transformer under heavy load from a shorted HV diode, a shorted magnetron or a failing transformer. All checks are in the high-voltage section.
Guide · Microwave
Moisture or condensation on the microwave door
Some condensation is normal with moist or covered foods. Moisture between the glass usually evaporates with the door left open. Persistent heavy moisture on an OTR unit can mean the cooling airflow is restricted.
Guide · Range Hood
Range hood turns on by itself or jumps to high speed
Many hoods (e.g. Broan Heat Sentry and similar) have a heat sensor that starts the fan or raises speed when it senses excess heat. That is a safety feature, not a fault. If it runs with a cold cooktop, suspect the sensor, a stuck switch or the control.
Guide · Range Hood
Range hood remote not working
Usually a dead coin battery, lost pairing or range. Pairing steps and battery type differ by model and remote generation.
Guide · Range Hood
Range hood damper flaps or chatters in wind
The backdraft flap is light and moves with wind pressure. Fixes: clean grease so it seals, replace worn foam stops, add a spring-loaded damper, or add light weight to the flap. Too many dampers reduce airflow.
Guide · Range Hood
Recirculating hood: odors not removed / charcoal filter
Ductless hoods rely on charcoal filters that cannot be washed and lose effect over time. Grease filters must be clean or the charcoal clogs fast. Replace charcoal on the maker's schedule.
Guide · Range Hood
Range hood LED lights flicker or dead (driver)
Check the LED module and connector first, then the LED driver/transformer and the light switch or control. Use the exact model part.
Guide · Range Hood
Hood blower hums but won't spin (capacitor)
A weak run/start capacitor or a greased-up blower wheel are the common causes. A switch fault or seized motor is next. No hum at all points to a thermal fuse, switch or supply.
Guide · Garbage Disposal
Garbage disposal trips breaker or reset button keeps popping
The reset button is the motor's overload protector; jams, overfeeding and long runs trip it. A breaker trip points to wiring, a shorted motor or a jam. Repeated trips after clearing jams = worn motor.
Guide · Garbage Disposal
Garbage disposal smells
Food residue builds up under the splash guard and in the chamber. Clean the baffle and flush with cold water while running.
Guide · Garbage Disposal
Sink water backs up into dishwasher
The dishwasher drain needs a high loop or air gap and must connect above the disposal. A clogged disposal or trap also pushes water back.
Guide · Garbage Disposal
Disposal sink flange leaking: reseal
Remove the disposal, reseat the sink flange with fresh plumber's putty and gaskets, then remount and leak test.
Guide · Garbage Disposal
Disposals on septic systems
Manufacturers say disposals are safe for properly maintained septic systems; septic-specific models add enzymes. This is maker guidance, not independent proof.
Guide · Garbage Disposal
Choosing disposal horsepower and type
Higher HP grinds more types of scraps; match to household size. Continuous feed needs a switch; batch feed starts with a stopper.
Guide · Microwave
Microwave runs but does not heat
No heat means the high-voltage circuit is not producing microwaves: HV fuse, HV diode, HV capacitor, magnetron, HV transformer, a door switch, or (on inverter models) the inverter board. Every internal test is high-voltage work for trained techs only, with the cord unplugged and the HV capacitor discharged and verified.
Guide · Microwave
Microwave dead, no display or power
Rule out the outlet and breaker/GFCI first. Inside, the usual cause is a blown line (main) fuse, often blown on purpose by the monitor switch when a door switch fails, so test the door switches before replacing the fuse. Thermal cutoffs and the control board are next. Internal work is high voltage: trained techs only.
Guide · Microwave
Microwave keeps blowing the line fuse when the door is opened or closed
The monitor switch is designed to short the line and blow the fuse if the door switches do not open in the right order. Worn latches, a misaligned door or a failed switch cause this. Replace the failed switch(es), check latch alignment, then replace the fuse with the exact rating.
Guide · Microwave
Microwave sparking or arcing inside
Rule out metal in the cavity first (foil, twist ties, metal-trimmed dishes, a rack on a model not meant for it). The most common part failure is a grease-soaked, carbonized waveguide cover. Chipped cavity paint and a damaged magnetron antenna cap are next. Stop using the unit until fixed, since continued arcing can damage the magnetron.
Guide · Microwave
Microwave turntable not turning
Check the easy parts first: tray seating, roller ring and the plastic coupler. If the coupler does not move while cooking, the turntable motor (under the cavity floor) is the likely fault. Motor access is outside the cavity: unplug, and on any model where the cabinet must come off, follow the HV capacitor warning.
Guide · Microwave
Microwave keypad not responding (or phantom presses)
Rule out control lock first. Then the usual causes are a worn or moisture-damaged membrane keypad or a loose ribbon at the control board. Unplugging the keypad ribbon separates a bad keypad from a bad board. The control board sits next to high-voltage parts on most models.
Guide · Microwave
Over-the-range microwave vent fan or cooktop light not working
Start with bulbs, grease filters and the fan's thermal protection. A fan that runs by itself is often a stuck relay on the control board or the board's automatic hot-cooktop protection reacting to heat below. Fan motor and relay tests are internal: high-voltage warning applies.
Guide · Range Hood
Range hood fan not running (lights may or may not work)
Split the call by whether the lights work. Lights and fan both dead points to supply power or the house wiring; lights OK but no fan usually means a loose blower connector, a seized wheel or a failed motor. A fan that runs and then cycles off is often a motor overheating on a grease-loaded filter.
Guide · Range Hood
Range hood light not working or flickering
Start with the lamp itself: swap a working lamp into the dead position to separate lamp from socket or wiring. Flicker is usually a loose connector. Repeated early burn-out on halogen/incandescent hoods points to a lamp of the wrong wattage.
Guide · Range Hood
Range hood weak suction / not clearing smoke and odor
Hoods are rarely weak by themselves; the usual causes are loaded filters, a damper that will not open, a blocked or undersized duct, too many elbows, or a house that cannot supply makeup air. A tissue test with and without the duct quickly shows whether the hood or the installation is at fault.
Guide · Range Hood
Range hood loud, rattling or vibrating
Separate airflow noise (rushing, whistling) from mechanical noise (rattle, grind, wobble). Airflow noise usually comes from a restricted or undersized duct, a stuck damper or dirty filters. Mechanical noise comes from a loose part, a debris-hit or unbalanced fan wheel, or worn motor bearings.
Guide · Range Hood
Range hood controls unresponsive or acting erratically
Electronic hood controls can lock up; a full power reset clears many cases. If not, check the ribbon or harness between the control panel and the main board, then replace the control panel or board. On hoods with Bluetooth or cooktop pairing, an active pairing can make the hood switch on by itself.
Guide · Range Hood
Grease or liquid dripping from the range hood
Most drips are grease that has saturated the filters or collected inside the hood because the filters were not cleaned or were missing. A second pattern is steam condensing inside a duct that runs through a cold space and running back down to the hood. Clean everything, then look at filter habits and duct routing.
Guide · Range Hood
Telescopic downdraft vent will not rise (or fan will not run)
Telescopic downdrafts have a lift motor and a separate blower. Most calls are power (cord unplugged in the cabinet, breaker), an obstruction that triggered the safety stop, or a button that was tapped instead of held. The blower is normally interlocked and only runs with the vent fully up.
Guide · Range / Oven
Electric oven not heating (bake or broil)
Most no-heat calls on electric ovens come down to a burned-out bake or broil element, a failed oven temperature sensor, or loss of one 120 V leg of the 240 V supply. Test elements and sensor with power off before suspecting the control board.
Guide · Range / Oven
Gas oven not heating (igniter glows, no flame)
On glow-bar ovens the igniter is wired in series with the gas safety valve; a weak igniter can glow but not pull enough current to open the valve. The igniter current check is an electrical test. Anything involving the gas valve, regulator, orifices or gas lines is off limits: refer to a licensed gas technician.
Guide · Range / Oven
Oven temperature inaccurate (runs hot or cold)
First measure properly: ovens cycle above and below setpoint, so use an average over several cycles. Small offsets are fixed with the control's calibration setting; large errors usually mean a drifting sensor, a weak element or igniter, or a door gasket leak.
Guide · Range / Oven
Electric surface element not heating (coil or radiant)
On coil tops, start with the element and its receptacle (swap with a working element of the same size). On radiant glass tops, test the element terminals under the glass, then the infinite switch that powers it. Electronic-control cooktops use relays on a board instead of infinite switches.
Guide · Range / Oven
Glass cooktop element stays on high / won't turn off
On knob-controlled cooktops this is almost always an infinite switch with welded contacts. On touch-control cooktops a relay on the control or relay board can stick closed. Note that radiant elements normally cycle on and off at lower settings; that cycling is not a fault.
Guide · Range / Oven
Oven door stuck locked after self-clean
The lock stays engaged until the cavity cools (most models release below about 550°F). If it stays locked when cold, the lock motor, its position switch or the control is at fault. Dead ovens after self-clean often have an open thermal fuse.
Guide · Range / Oven
Control panel beeping, phantom key presses or F-codes
Most keypad faults come from moisture or grease behind the touch overlay, or a worn membrane, often after self-clean or a boilover. Isolate the keypad from the control by unplugging its ribbon before buying a board.
Guide · Range / Oven
Induction cooktop not detecting pan
Induction only heats magnetic cookware large enough for the zone and centered on it. Rule out cookware first; if good pans fail on a zone, the zone's coil, generator (inverter) board or firmware is at fault, which is board-level service.
Guide · Range / Oven
Oven fan noisy (convection or cooling fan)
Convection fan noise is usually worn motor bearings or a loose/warped blade. Note that many ovens run a cooling fan after cooking ends; that is normal. A grinding noise during self-clean start can be the door lock motor rather than a fan.
Guide · Refrigerator
LG Craft Ice not making round ice
Craft Ice is slow by design and needs a cold freezer, water and the right mode. Rule out start-up time, mode setting and bin position before blaming the Craft Ice module.
Guide · Refrigerator
Samsung Family Hub screen frozen or blank
The Family Hub screen has its own power switch inside the right door. A switch reset fixes most freezes; if not, a full power cycle, software update or service on the screen/board is next.
Guide · Refrigerator
Water filter light won't reset / filter bypass
Most filter lights never reset on their own. The reset key combination depends on the model. On RFID-filter models (e.g. GE), a non-genuine or badly seated filter can disable ice and water.
Guide · Refrigerator
Refrigerator door alarm keeps beeping
The alarm follows the door switch, not the door itself. A door that doesn't fully close, a blocked shelf, a misaligned door or a failed switch keeps it sounding. Some beeps are power-outage alerts instead.
Guide · Refrigerator
Fridge or freezer door not sealing
A bad seal lets moist air in, causing frost, sweating and long run times. Most cases are leveling, a folded gasket or a blocking item; the gasket itself is the last step.
Guide · Refrigerator
Refrigerator clicking, compressor won't start (start relay)
The classic pattern is a failed start relay: the compressor can't start, overheats in seconds and the overload clicks off, then retries. Replace the relay first; if it keeps clicking with a good relay, the compressor is suspect (sealed-system work, refer out).
Guide · Refrigerator
Fresh-food light out (LED or bulb)
On LED models the cause is usually a failed LED module, the door switch, or the board that powers the LEDs. A light failure alone does not affect cooling.
Guide · Refrigerator
Refrigerator water tastes or smells bad
Bad taste is almost always an old or wrong filter, water sitting in the lines, or new-install tubing. Fix the filter and flush before suspecting the supply itself.
Guide · Refrigerator
Water dispenser slow or weak flow
Work from the filter outward: filter, supply flow at the fridge, then the fridge's inlet valve and lines. Freezing in the door line is another cause.
Guide · Refrigerator
Sabbath mode: lights, dispenser or alarms not working
Sabbath mode disables lights, alarms, dispenser and the panel response while cooling continues. It can be turned on by accident. Exit it with the model's key combination; it may also time out (LG 96 h, Samsung 85 h).
Guide · Refrigerator
Refrigerator temperature fluctuates (warm, then cold)
Swings usually come from a frosted evaporator (defrost failing), a sticking damper, or a sensor problem. Check frost first, then damper and thermistor.
Guide · Refrigerator
Demo / showroom mode stuck (OFF, OF OF, 'cooling off')
Demo (showroom) mode runs lights and display with cooling off. It's a key combination, not a repair. If it returns after exit, the panel may be faulty.
Guide · Freezer
Freezer lid or door not sealing
Chest lids and upright doors fail to seal from torn or hard gaskets, a tilted cabinet, overfilled baskets or ice on the gasket. Fix the seal before chasing cooling parts.
Guide · Freezer
Freezer door hard to open right after closing
Warm air let in cools and contracts, creating a brief vacuum. It is normal on well-sealed units and clears in under a minute. Persistent sticking points to a gasket stuck by ice or a sticky gasket.
Guide · Freezer
Freezer clicking, compressor not running
Same pattern as fridges: start relay or overload most often, then supply voltage, then compressor. Compressor work is sealed-system: refer.
Guide · Freezer
Freezer showing a sensor error code (E1/E2 type)
Most digital freezers flag thermistor faults with E-codes, but numbers differ by brand. Confirm the code meaning in the manual, then test the thermistor and its wire.
Guide · Ice Maker
Ice melting in the bin (portable / undercounter)
Many countertop and some undercounter machines have unrefrigerated bins: melting is normal and the melt is recycled or drained. Excess melting comes from a hot location, a door left open or poor ventilation.
Guide · Ice Maker
Ice machine slime, mold or scale
Scale and biofilm slow harvest and trigger long-cycle codes (e.g. Hoshizaki 2 beeps, Scotsman 2). Clean and sanitize per the manufacturer's procedure and replace the water filter.
Guide · Ice Maker
Commercial cuber long freeze or long harvest alarm
Long freeze usually means poor heat rejection or water problems; long harvest usually means scale or harvest components. Do the safe checks; refrigeration work goes to an EPA 608-certified tech.
Guide · Ice Maker
Nugget/flake machine auger overload or no ice sensed
Scale on the evaporator and auger is the most common cause of auger overload. Low water starves the freezing cylinder. Descale and check water before replacing gear motors.
Guide · Refrigerator
Refrigerator not cooling (both sections warm)
Rule out settings, demo/cooling-off mode and airflow first, then confirm whether the compressor and condenser fan run. If the compressor is running but nothing gets cold, or it won't start even though the start components and power check out, it's a sealed-system problem and goes to an EPA 608-certified tech.
Guide · Refrigerator
Fresh-food section warm, freezer cold
On single-evaporator units, cold air comes from the freezer through a damper or duct. A frosted evaporator, a stopped evaporator fan or a stuck damper will starve the fridge side. On dual-evaporator units (many Samsung models), the fridge evaporator, its fan and its defrost circuit are the usual suspects.
Guide · Refrigerator
Defrost system failure (frosted evaporator)
The defrost system (heater, defrost thermostat/thermal fuse or sensor, and the timer or control board) must melt the coil frost every few hours. If any of them fails, the coil turns into a block of ice and airflow stops. Test the heater and the limit with the coil still cold.
Guide · Refrigerator
Ice maker not making ice
Confirm the freezer or ice room is cold enough, the ice maker is on and the bucket isn't fooling the full sensor, then run the ice maker test. If the test runs but no water arrives, look at water pressure, the filter, a frozen fill tube or the inlet valve.
Guide · Refrigerator
Water dispenser not working (ice maker may still work)
If ice is still being made, the water supply reaches the valve, so the fault is usually a frozen door line, the dispenser-side valve coil, the dispenser switch or a lock mode. Isolate the problem by section.
Guide · Refrigerator
Refrigerator leaking water (inside or on the floor)
Water inside the cabinet usually means a clogged or frozen defrost drain. Water on the floor usually comes from the supply line, inlet valve, filter housing, or an overflowing or mis-seated drain pan. Level and tilt also matter.
Guide · Refrigerator
Refrigerator noisy (fans, compressor, clicking)
Find where the noise is and when it happens. Scraping in the freezer that stops when the door opens is the evaporator fan, often hitting ice. A squeal from the bottom rear is the condenser fan. Clicking every few minutes with no cooling is a start problem.
Guide · Refrigerator
Fresh-food section too cold (freezing food)
Check settings, vent placement, room temperature and the ice-maker-without-water condition first. If those are fine, suspect a damper stuck open or a sensor reading warm.
Guide · Refrigerator
Samsung in-door ice maker / ice room icing up
Moist air leaking into the in-door ice room freezes on the fan, ice maker and bucket. Thawing it only fixes it for a while. A lasting fix means finding and sealing the air leak and correcting airflow, often with Samsung's updated parts and procedures.
Guide · Refrigerator
LG linear/inverter compressor fridge not cooling
Rule out demo mode, airflow, fans and defrost first, then use LG's forced-run diagnostic to see whether the compressor runs. If the compressor runs but doesn't cool, or won't start with a good board, it's a sealed-system failure: refer it to LG service or an EPA 608-certified technician and check the compressor warranty.
Guide · Sump / Well Pump
Sump pump runs but does not pump water
Most cases are an air lock, a check valve that is backwards or stuck, a blocked intake or impeller, or a frozen or blocked discharge. Work from the discharge back to the pump.
Guide · Sump / Well Pump
Sump pump runs constantly
Either water is really coming in that fast, or the float is stuck on. A pump that runs dry will overheat, so this is urgent.
Guide · Sump / Well Pump
Sump pump won't turn on (float or power)
Prove power, then prove the pump by bypassing the float, then fix the float. Most residential pumps with a piggyback plug make this a two-minute test.
Guide · Sump / Well Pump
Battery backup sump pump alarm
Backup controllers alarm for four main reasons: no AC power, low or failed battery, blown fuse, or the backup pump had to run. A backup pump run means the primary pump needs attention now.
Guide · Sump / Well Pump
Check valve bang, water hammer and noisy sump pump
A bang right after shutdown is the check valve slamming as the water column falls back. Rattles and vibration come from loose pipe, debris or a damaged impeller.
Guide · Sump / Well Pump
Well pump short cycling (waterlogged tank / pressure switch)
Short cycling is usually a pressure tank that has lost its air charge (waterlogged) or a precharge set wrong for the switch. It wears out the pump motor and pressure switch quickly.
Guide · Sump / Well Pump
No water from the well
Check what you can safely see above ground: breaker, pressure switch, sensing tube, low-pressure cutoff and the drive's fault display. If those are good, the problem is down the well (pump, motor, cable, water level) and needs a licensed well contractor to pull the pump.
Guide · Sump / Well Pump
Sewage / ejector pump high-water alarm
Sewage basins are sealed and carry sewer gas and pathogens. Most alarms are a float stuck by grease or wipes, a tripped pump, or a blocked discharge/check valve. Keep work to non-invasive checks unless trained and equipped.
Guide · Thermostat
Thermostat blank screen / no power
A dead display is usually a missing 24 V supply, not a bad thermostat. Work from batteries and breakers to the furnace door switch, condensate float switch, board fuse and transformer. A board fuse that blows again points to a shorted thermostat or outdoor wire.
Guide · Thermostat
Thermostat calls but heat or cooling does not start
Split the problem in two: is the thermostat sending 24 V on the call wire, and is the equipment responding to it? A jumper test at the board answers that in minutes.
Guide · Thermostat
System short cycles (turns on and off quickly)
Short cycling can be a thermostat placement or power-stealing problem, but often it is the equipment tripping on a safety (high limit, frozen coil, float switch). Watch one full cycle and see who ends it: the thermostat or the equipment.
Guide · Thermostat
Thermostat reads or holds the wrong temperature
Compare the thermostat reading with a reference thermometer at the same spot. If the reading is wrong, look at location, drafts and sensors; if the reading is right but the room never reaches setpoint, the equipment is undersized, starving for air or faulty.
Guide · Thermostat
Smart thermostat offline / Wi-Fi problems
Separate network problems (router, credentials, internet) from power problems: many smart thermostats switch the radio off when batteries or borrowed power run low. Read the brand's code first.
Guide · Thermostat
Heat pump blows cold on heat (or warm on cool): O/B setting
The O/B terminal drives the reversing valve. Most brands energize it in cooling (O); Rheem and Ruud typically energize it in heating (B). A wrong O/B setting reverses the modes. Check the equipment diagram, not wire color.
Guide · Thermostat
Auxiliary heat runs too much or all the time
Aux heat should only help when the heat pump cannot keep up. Constant aux usually means wrong wiring/settings (aux on the heat pump terminal, emergency heat left on), big setback recoveries, or a heat pump that is not producing heat.
Guide · Thermostat
Replacing an old mercury or 2-wire thermostat
First identify the system: low-voltage 24 V, millivolt (wall furnace/gas fireplace) or line-voltage (120/240 V baseboard). Most smart thermostats only fit 24 V systems. Old dial/lever units often contain a mercury bulb that must be recycled, never trashed.
Guide · Thermostat
Installing a C-wire adapter (Nest Power Connector, ecobee PEK and similar)
An adapter mounts at the furnace/air-handler board and lets the existing wires carry both the calls and constant 24 V. Check compatibility first: dual-transformer, fan-coil and communicating systems are commonly excluded.
Guide · Trash Compactor
Trash compactor will not start
Most no-starts are power, an unlatched drawer, or the start sequence (key to Start, or On plus foot-actuated start). After that, test the drawer, key/start, toe/foot and directional switches, then the motor.
Guide · Trash Compactor
Ram stuck down or will not travel
Check the drive chain/gears, then the directional switch, then the power nuts on the power screws. The ram can be raised by turning the drive gear by hand with the unit unplugged.
Guide · Trash Compactor
Motor hums but the ram does not move
A humming stalled motor points to a mechanical jam (chain, gear, power nuts, overfilled bin) or a motor/start failure. Unplug quickly; continued humming overheats the motor.
Guide · Trash Compactor
Bad odor from the trash compactor
Trapped food or leaked liquid under the bag and on the ram are the usual sources. Clean, replace the charcoal filter/odor control as the user guide directs, and add baking soda.
Guide · Trash Compactor
Trash compactor drawer will not open
The drawer opens only with the ram fully up and no Solid/lock cycle active. Otherwise look for debris in the tracks, bad rollers or a foot pedal/catch problem.
Guide · Trash Compactor
Noisy trash compactor (banging, squealing)
Worn plastic gear teeth, chain or power-screw sockets, dry power nuts, or a sticking directional switch.
Guide · TV
TV turns on or off by itself (HDMI-CEC, mobile power-on)
Most phantom power events come from HDMI-CEC (Samsung Anynet+, LG SimpLink): a connected device sends a power command. Network 'power on' features and a damaged cord are the other causes.
Guide · TV
TV switches HDMI input by itself
HDMI-CEC 'one touch play' lets a device grab the input. Turning CEC off and clearing saved device history usually stops it.
Guide · TV
Picture too dark or dims on its own (energy saving / eco sensor)
Usually settings, not hardware: energy saving, eco/ambient light sensors and Eco picture modes. Rule these out before suspecting the backlight.
Guide · TV
Wrong colors or green / purple tint
The TV's built-in picture test splits the problem: if the test pattern is wrong, it is the TV (panel or board); if it looks fine, the cause is the source, cable or settings.
Guide · TV
Audio out of sync with picture (lip sync)
Check whether it's every source or one channel. Use the TV's AV sync / bypass controls, the soundbar's own delay, and PCM output.
Guide · TV
Apps freeze, crash or won't load
Separate network from app: test on a phone hotspot. One app failing is usually the app; all apps failing points to network or TV software.
Guide · TV
No sound from TV speakers
Most cases are mute/volume or the output still set to an external speaker. The built-in sound test separates TV speakers/amp from source problems.
Guide · TV
Bluetooth / smart remote won't pair
Smart remotes use Bluetooth/RF for most keys and IR only for a few (often power). Fix batteries first, then reset and re-pair close to the TV sensor.
Guide · TV
TV won't connect over Ethernet (wired)
Work from the cable outward: cable and port lights, router port, then status screen and modem/ISP.
Guide · TV
Roku TV / Fire TV: black screen but sound plays
First prove it isn't input or source (press Home, change input, remove devices). Then the flashlight test: a faint image means backlight failure.
Guide · TV
Flicker only in HDR / Dolby Vision or from one HDMI source
Usually the enhanced HDMI mode (LG HDMI Ultra HD Deep Colour, Samsung Input Signal Plus) with a cable, hub or source that can't hold the bandwidth.
Guide · TV
HDCP error, purple screen or protected content won't play
The HDCP handshake failed somewhere in the HDMI chain. Simplify the chain, reseat cables, power up in order, and confirm HDCP 2.2 for 4K/HDR.
Guide · TV
TV won't turn on (standby light only, or blinking)
Separate power-delivery problems (outlet, surge strip, remote) from internal failures. A steady standby light with no response is often remote or button related; a blinking light after a clean power cycle on a good outlet is a hardware fault, usually the power supply board.
Guide · TV
Sound but no picture (backlight / LED strip test)
The flashlight test tells you in one minute whether the panel is producing an image with no backlight. If you can see a faint image, the LED strips or LED driver are the likely fault; if not, look at T-con or main board.
Guide · TV
Picture flickering or dimming
Rule out picture settings (energy saving, ambient light sensor) and the source/cable first. Flicker on the TV's own menus points to backlight or power board.
Guide · TV
Vertical or horizontal lines on screen (T-con vs panel)
Decide if the lines are in the source, the T-con/ribbons, or the panel. Lines that pass through the TV's own menu are internal; single fixed thin lines usually point to the panel's COF/ribbon, grouped or shifting lines more often to the T-con.
Guide · TV
TV stuck on logo / restarting (boot loop)
Usually firmware or main board, occasionally power supply. Try a full power drain and a firmware recovery/factory reset before replacing boards.
Guide · TV
"No Signal" or HDMI input problems
Most no-signal calls are the wrong input, a bad cable, or a source device that is off or sending a format the TV can't show.
Guide · TV
TV won't connect to Wi-Fi / network error codes
Find out whether the TV can't join the router or joins but has no internet. A phone hotspot test splits TV vs. home network fast.
Guide · TV
TV remote not working
Check batteries, then whether the remote is IR or Bluetooth/RF. Re-pair smart remotes; test IR remotes with a phone camera.
Guide · TV
Half of the screen dark
A dim half that still shows an image is usually backlight (strips or connector). A completely black side with no image points more to the T-con or ribbon. Answers vary by model.
Guide · TV
Factory reset and firmware update
Try a soft restart first, then a factory reset from menus, and if menus are unreachable use the hardware reset button (Roku TV). Update firmware afterward.
Guide · Washer
Washer smells like burning
Stop and unplug first. Most cases are a slipping belt, a dragging motor or pump, or a burnt connector; on front-loaders the motor control board can scorch.
Guide · Washer
Washer fills then drains at the same time (siphoning)
Usually the drain hose is pushed too far into the standpipe or sealed in it, so water siphons out. A drain hose below the tub level can do the same.
Guide · Washer
Detergent dispenser not emptying
Usually low water flow, clogged siphon caps or jets, or overfilling. Check flow first, then clean the drawer and its housing.
Guide · Washer
Washer shaking on a second floor or wood floor
Wood framing flexes, so levelling and balance matter more. Confirm shipping bolts are out, level and lock the feet, and rule out suspension wear.
Guide · Washer
Bleach or fabric softener not dispensing (or dispensing too early)
Softener and bleach cups use siphons. Overfilling, a clogged siphon or low water flow causes trouble.
Guide · Washer
Clothes come out with lint or residue
Common causes are overloading, mixing lint-shedding and lint-catching fabrics, too much or wrong detergent, and a clogged pump filter.
Guide · Washer
Hot and cold water reversed (HC, F0E4, 4C2)
The hoses are swapped at the faucet or at the washer. Swap them; no parts needed.
Guide · Washer
Clean-washer reminders and clean-cycle codes (CL, rL, F0E7)
These are reminders or load-detected messages, not faults. Run the clean cycle with an empty drum.
Guide · Washer
Washer trips the GFCI or breaker
Note when it trips. At plug-in: cord or board. During fill: water reaching wiring. During heat: heater leakage (some front-loaders). During spin: motor.
Guide · Washer
Wash water not warm enough
Most washers rely on the home water heater; long pipe runs and eco settings reduce temperature. Check supply, hoses, valve and sensor.
Guide · Washer
Washer-dryer combo washes but does not dry
Combos are ventless and dry slowly. Clean the condenser/lint path, check load size and power (many need 240 V), then check heater or heat pump.
Guide · Washer
Washer controls do not respond (lock, download, power failure)
Many no-response calls are control lock, child lock, software download or power failure messages.
Guide · Dryer
Clothes come out wrinkled
Usually overload, over-drying, or clothes left in the drum. Check moisture sensing and cool-down.
Guide · Dryer
Dryer drum light not working
Bulb or LED module, door switch, or drum-light circuit. Some GE Profile models show a code for the drum light circuit.
Guide · Dryer
Dryer steam features not working
Steam dryers use a feeder or a hose supply. Check water, inlet filter and valve, then the steam generator thermistor.
Guide · Dryer
Water or condensation inside the dryer
Usually a long, cold or sagging vent where moisture condenses and runs back, or a blocked vent.
Guide · Dryer
Lint filter not detected or lint filter codes
Several dryers sense the lint filter. Seat the filter fully, clean it, then check the sensing switch.
Guide · Dryer
Dryer will not connect to the app (Wi-Fi)
Most cases are 2.4 GHz network, registration or router issues; a few are module faults.
Guide · Dryer
Dryer smells like gas (BLOCKED: refer)
Safety only. Do not diagnose the gas train. Leave, avoid ignition sources, and call the gas utility or a licensed gas technician.
Guide · Dryer
Clothes too hot / dryer running hot
Most often restricted airflow; also a failed cycling thermostat, thermistor or stuck heater relay.
Guide · Dryer
Ventless dryer water tank and condensate codes
Condenser and heat-pump dryers collect water in a tank or pump it out. Empty tank, clean float, clear hose.
Guide · Dryer
Reading airflow / vent-test codes
Airflow codes rate vent restriction. Clean filter, then whole duct, then hood.
Guide · Washer
Washer won't drain (water left in tub, drain codes)
Most no-drain calls are a clogged pump filter or a hose problem, not a dead pump. Clear the drain path first, then confirm the pump runs and moves water before condemning the pump or board.
Guide · Washer
Washer won't spin (clothes soaking wet)
No-spin is often a drain problem or an unbalanced-load lockout, not a drive failure. Rule out drain, balance, level and lid/door lock before going to the motor, belt, coupler or shifter.
Guide · Washer
Washer won't start
Check power, control lock, door/lid, and any install-check requirement before suspecting boards. Many 'won't start' calls are lock modes or lid/door issues.
Guide · Washer
Washer not filling or filling slowly
Start with the supply side: faucets, hoses, inlet screens and pressure. Only then test the inlet valve coils and the level sensing.
Guide · Washer
Washer leaking
Find where and when it leaks. Most leaks are hoses, the front-load pump filter cap, debris at the door boot, or suds. Torn boots and tub/pump leaks are next.
Guide · Washer
Loud banging, roaring or shaking (bearings / suspension)
Separate the sound: a roar that grows with speed points to the tub bearing; banging and walking point to suspension (rods, shocks, springs) or a broken spider arm; rattle only during drain points to the pump.
Guide · Washer
Front-load washer smells (mold/mildew at the gasket)
Odor comes from residue and standing moisture in the boot, dispenser and pump filter. Fix habits (HE dose, door open, prompt unloading) and run a monthly clean cycle.
Guide · Washer
Door or lid won't lock / won't unlock
Clear obstructions and check the strike first. Then decide electrical vs mechanical: no click = lock solenoid/motor, wiring or control; click but no latch = mechanical jam or broken strike.
Guide · Washer
Repeated unbalanced-load codes
Occasional unbalance is a loading issue. Unbalance on small, balanced loads points to leveling, shipping bolts, floor, or worn suspension.
Guide · Washer
Top-load not agitating (fills and drains OK)
On older Whirlpool/Kenmore direct-drive top-loads, fill-and-drain-OK but no agitate/spin is the classic broken motor coupler. On newer models, look at the shift actuator/clutch, lid lock and motor.
Guide · Washer
Samsung top-load banging / unbalance (suspension rods)
Worn suspension rods let the tub hit the cabinet. After ruling out load and leveling, replace all four rods as a model-matched set.
Guide · Washer
Reading stored codes and service/test mode (overview)
Entry sequences differ by model and generation. Always confirm on the tech sheet inside the cabinet; the sequences below are examples reported for specific model families.
Guide · Water Heater
Electric water heater: no hot water
Standard residential electric tanks use two elements and two thermostats in non-simultaneous mode: the upper thermostat heats the top first, then hands power to the lower one. Totally cold water usually means a tripped high-limit (ECO), a dead upper element or a failed upper thermostat. Always find out why the ECO tripped before calling the job done.
Guide · Water Heater
Water heater: not enough hot water / runs out fast
On electric tanks a failed lower element or lower thermostat leaves only the top of the tank hot. Other common causes on any tank are a broken dip tube, a crossed hot/cold connection in the house plumbing, reversed connections at the heater, and simple undersizing for the demand.
Guide · Water Heater
Water heater: water too hot or ECO keeps tripping
On electric tanks overheating usually means a thermostat welded closed or not clamped tightly against the tank, or a grounded element heating outside thermostat control. On gas tanks it is a gas control fault and must be referred. Treat it as a safety call: overheated water is a scald and tank-pressure hazard.
Guide · Water Heater
Water heater leaking: fitting or tank?
The key question is whether the water comes from the plumbing (repairable) or the tank itself (replace the heater). Work from the top down: supply connectors, nipples, T&P valve and its pipe, drain valve, element gaskets. Water from the bottom, under the jacket, or a rusty combustion chamber means the tank has failed.
Guide · Water Heater
Water heater noisy: popping, rumbling, crackling, humming
Rumbling and popping are usually sediment and scale at the bottom of the tank (gas) or on the elements (electric). They rarely mean the tank is failing but they cut efficiency. Banging or squealing can also come from high pressure and thermal expansion, so check pressure before blaming sediment.
Guide · Water Heater
Hot water smells like rotten eggs (anode reaction)
Bacteria in some water supplies (common with wells) react with sulfates and the tank's sacrificial anode to make hydrogen sulfide. If only the hot water smells, the heater is the source. Fixes are an anode change to aluminum/zinc or a powered anode, plus a disinfecting shock; never just remove the anode.
Guide · Water Heater
Gas water heater: pilot won't light or won't stay lit (diagnose and refer)
Standing-pilot gas tanks use a thermocouple or thermopile heated by the pilot to hold the gas valve open; FVIR models add a thermal switch and flame arrestor. This is a gas appliance: the tech's role here is to read the status light, confirm gas supply, note symptoms and hand off. Pilot assembly, thermocouple/thermopile, burner and gas valve work go to a licensed plumber or gas technician.
Guide · Water Heater
Tankless: error code, no ignition at low flow, or temperature swings
Many tankless complaints are water-side: flow below the activation threshold, a clogged inlet screen, low-flow aerators, or scale in the heat exchanger. Gas supply, venting and combustion codes are blocked: diagnose and refer. Read the code first, then work the water side.
Guide · Water Heater
T&P relief valve dripping or discharging
The T&P valve is the tank's last line of defense. It may be failing, or it may be doing its job because the house pressure is too high or thermal expansion has nowhere to go (check valve or PRV on the supply). Diagnose with a pressure gauge; replacement of the valve itself is licensed plumber work in many jurisdictions. Never cap or plug it.
Guide · Water Softener
Hard water returning (softener has salt but water is hard)
Most hard-water callbacks come from salt that is not reaching the water (bridge or mush), wrong settings, or a regeneration that is not drawing brine. Check the brine tank first, then programming, then the valve.
Guide · Water Softener
Softener not regenerating
A softener that never regenerates usually has a drive problem (motor, gears, stuck piston), a programming problem, or a meter that is not counting. Error codes on Fleck and Clack valves point straight to the drive.
Guide · Water Softener
Brine tank overflowing or holding too much water
Excess brine water means the valve refills but does not draw brine out, or the refill does not stop. Typical causes are a plugged injector or screen, a kinked or scaled brine line, a stuck float, or internal valve leakage.
Guide · Water Softener
Salt level not going down
If salt is not used, either the unit is not regenerating, the salt is not dissolving (bridge), or brine is not being drawn. Rule out a bridge first because it is the quickest fix.
Guide · Water Softener
Low water pressure after the softener
Pressure loss across a softener usually comes from a clogged pre-filter, fouled or broken-down resin, resin escaping into lines, or a valve stuck partly in a regeneration position. Bypassing the unit isolates it quickly.
Guide · Water Softener
Resin beads in faucets, aerators or toilet tanks
Beads in the plumbing almost always mean a cracked or loose distributor/riser tube or bottom basket in the resin tank. Very old resin can also break into fines that pass the screens.
Guide · Water Softener
Leaking bypass valve or valve-to-plumbing connection
Bypass leaks are usually worn O-rings in the bypass body or yoke connection, a cracked plastic bypass, or strain from misaligned plumbing. Repair is O-ring replacement or bypass replacement.
Guide · Water Softener
RO system: slow flow or no water at the faucet
Slow RO water comes from a low tank air charge or failed bladder, clogged pre-filters, a fouled membrane, low feed pressure, or a clogged post-filter. A timed flow test splits filter/pressure problems from membrane problems.
Guide · Water Softener
RO storage tank: checking and setting the air pre-charge
The tank pushes water out using an air charge behind a diaphragm. The charge must be read and set only with the tank empty of water.
Guide · Water Softener
RO system will not shut off (water always running to drain)
The auto shut-off (ASO) valve closes when tank pressure reaches about two-thirds of feed pressure. If the tank never gets there, or the check valve leaks back, the system keeps running to drain.
Guide · Wine Cooler
Wine cooler not cooling (thermoelectric vs compressor)
First identify the type: thermoelectric units (quiet, no compressor) are limited by room temperature and depend on their fans and heat sinks; compressor units depend on a clean condenser and working fans. Many no-cool calls are ventilation, door seal or room temperature problems.
Guide · Wine Cooler
Wine cooler too cold or bottles freezing
Over-cooling comes from a cold room (especially with thermoelectric units, which have no heater), an iced evaporator, a blocked internal fan, or a failed sensor/control.
Guide · Wine Cooler
Condensation on the glass door or water on the floor
Door sweating is usually humid room air on cold glass, made worse by a leaking gasket, blocked vents or frequent openings. Water on the floor usually means the drip tray is out of place or the defrost drain is clogged.
Guide · Wine Cooler
Noisy wine cooler or beverage center
Most noise is the unit not being level or touching something, loose parts, or a fan blade hitting ice or debris. Thermoelectric units only have fans, so noise there is almost always a fan. Some fan cycling is normal.
Guide · Wine Cooler
Display shows an error, HI/LO, or does not respond
Many alarms (HI/LO, door) clear once the door is closed and the cabinet recovers. Sensor codes point to a thermistor or its wiring. A dead display with power present is usually the display board.
Guide · Wine Cooler
Door seal problems and interior light not working
A worn or poorly seated gasket causes warm cabinets, moisture and long run times. A dead light is usually the bulb/LED, a loose connection or the light switch, which on many units is part of the display board.
Error codes by appliance
Refrigerators
127 codes · 11 brands
Washers
185 codes · 10 brands
Dryers
112 codes · 8 brands
Dishwashers
131 codes · 12 brands
Ranges & Ovens
104 codes · 9 brands
Microwaves
59 codes · 6 brands
Air Conditioners
124 codes · 13 brands
TVs
55 codes · 9 brands
Water Heaters
83 codes · 9 brands
Garbage Disposals
0 codes · 0 brands
Freezers
36 codes · 8 brands
Ice Makers
36 codes · 5 brands
Range Hoods
0 codes · 0 brands
Dehumidifiers
49 codes · 9 brands
Furnaces
63 codes · 6 brands
Thermostats
57 codes · 4 brands
Sump & Well Pumps
10 codes · 2 brands
Garage Door Openers
62 codes · 3 brands
Water Softeners & Filters
19 codes · 4 brands
Wine & Beverage Coolers
22 codes · 3 brands
Trash Compactors
0 codes · 0 brands
Tech Fundamentals
0 codes · 0 brands