Water Heaters

7 components3 common failuresBradford White

Bradford White RE (electric) and RG (gas) residential tanks: quick sheet

Bradford White residential upright and lowboy tanks: RE-prefix electric (e.g. RE250T6 = 50 gal tall) and RG-prefix atmospheric gas (Defender Safety System). Sold through plumbing wholesalers, not big-box stores. Newer ERE models with ICON E electronic control are a different platform. Date from the serial number letters (see below).

7 components4 common failuresRinnai

Rinnai RU / RUR (SENSEI) condensing tankless: quick sheet

Rinnai condensing residential tankless: RU-series (RU199iN/eN, RU180, RU160, RU130; indoor 'i' and outdoor 'e'), RUR models with built-in recirculation. Older non-condensing RL / V-series and RE models differ. Rinnai serial numbers encode year then month in the first four digits.

6 components3 common failuresNavien

Navien NPE-A2 condensing tankless (ComfortFlow): quick sheet

Navien NPE-180A2, NPE-210A2 and NPE-240A2 (A2 = built-in buffer tank and recirculation pump, 'ComfortFlow'); the NPE-S2 models (150S2-240S2) are the same generation without ComfortFlow. Earlier NPE-A (first generation) units differ in controls.

6 components2 common failuresRheem, Ruud

Rheem RTGH condensing tankless (RTGH-84/95, Performance Platinum ECOH): quick sheet

Rheem RTGH 'Super High Efficiency' condensing indoor tankless: RTGH-84DVLN, RTGH-95DVLN (current suffix -3), Wi-Fi versions RTGH-95DVELN-3, and the similar Performance Platinum ECOH160DVLN-3 with EcoNet and LeakGuard. RTG (non-condensing) is a different line.

6 components3 common failuresRheem, Ruud

Rheem ProTerra hybrid heat pump water heater: quick sheet

Rheem Performance Platinum / Prestige ProTerra hybrid electric heat pump water heaters, 40, 50, 65 and 80 gal, model numbers starting XE…H (e.g. XE80T10H45U0 = 80 gal, 30 A; XE80T10H22U0 = 15 A plug-in-style version). 30 A and 15 A families exist.

6 components2 common failuresA.O. Smith, State

A.O. Smith Voltex / ProLine XE Voltex hybrid heat pump water heater: quick sheet

A.O. Smith Voltex hybrid heat pump water heaters: older HPTU-50N/66N/80N, current ProLine XE Voltex HPTU-50CTA, FPTU-80, and Voltex AL Smart HPTS (anti-leak). Model letters vary by channel; confirm on the rating plate.

6 components4 common failuresA.O. Smith, State, Rheem, Ruud, Richmond, Bradford White, Whirlpool

Electric tank water heater: field service manual

Residential 240 V dual-element tank heaters (roughly 30-80 gal) with surface-mount upper thermostat/ECO and lower thermostat

4 components3 common failuresA.O. Smith, State, Rheem, Ruud, Bradford White, Whirlpool

Gas tank water heater (atmospheric and power-vent): diagnostic and electrical-side manual

Residential standing-pilot FVIR tanks with thermopile electronic gas controls, and 120 V power-vent tanks; diagnosis and electrical/water-side only

5 components3 common failuresRinnai, Navien, Noritz, Rheem, A.O. Smith, Bradford White

Gas tankless water heater: field service manual (water side and diagnostics)

Residential non-condensing and condensing gas tankless units with digital controllers

4 components3 common failuresRheem, A.O. Smith, Bradford White, State

Heat pump (hybrid) water heater: field service manual

Residential integrated heat pump water heaters with backup resistance elements

Diagnostic guides · 16

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.

4 steps ~60 minmoderate

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.

7 steps ~60 minmoderate

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.

5 steps ~20 minadvanced

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.

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.

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.

4 steps ~90 minmoderate

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.

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.

5 steps ~45 minmoderate

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.

4 steps ~45 mineasy

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.

5 steps ~75 mineasy

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.

6 steps ~90 minmoderate

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.

4 steps ~45 minmoderate

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.

5 steps ~30 mineasy

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.

5 steps ~60 mineasy

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.

6 steps ~60 minmoderate

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.

6 steps ~45 minmoderate

Installation · 3

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.

6 steps ~240 minadvanced

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.

3 steps ~15 minadvanced

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.