Sump & Well Pumps

Floats, check valves, backup alarms, pressure tanks and switches.

2 field manuals · 10 error codes · 16 guides · 2 brands

Field service manuals

Residential sump pump systems: field service manual

120 V residential submersible and pedestal sump pumps, float switches, check valves, discharge piping and DC battery backup systems

4 components4 common failuresZoeller, Wayne, Liberty, Superior Pump, Basement Watchdog, Little Giant, Pentair

Manual · Sump / Well Pump

Residential well pump systems: field service manual

Private-well systems with submersible or jet pumps, captive-air pressure tanks, mechanical pressure switches and constant-pressure drives (e.g. Franklin SubDrive/MonoDrive)

4 components4 common failuresGoulds, Red Lion, Franklin Electric, Pentair, Wayne, Others

Diagnostic guides · 15

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.

4 steps ~45 minmoderate

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.

5 steps ~30 mineasy

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.

5 steps ~45 mineasy

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.

5 steps ~60 minadvanced

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.

5 steps ~60 minadvanced

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.

6 steps ~30 mineasy

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.

4 steps ~40 mineasy

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.

5 steps ~45 minmoderate

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.

4 steps ~30 mineasy

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.

4 steps ~45 minmoderate

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.

4 steps ~30 mineasy

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.

5 steps ~60 minadvanced

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.

5 steps ~60 minmoderate

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.

5 steps ~60 minadvanced

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.

4 steps ~45 minmoderate

Installation · 1

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.

5 steps ~90 minmoderate