Well Pump Not Working? A Safe Troubleshooting Order

When a well pump stops working, check in this order: the breaker or fuse, the pressure switch, the control box (on 3-wire submersibles), the pressure tank, and only then the pump and the well. Most of the first checks need nothing more than your eyes and a pressure gauge. The moment a check calls for a meter on live terminals or pulling the pump, it is a job for a licensed pump installer. The steps below follow the troubleshooting tables in Franklin Electric’s AIM manual for submersibles and Goulds’ manual for jet pumps.

Safety first

Well pump circuits are commonly 230 V. Goulds factory-wires its larger jet pumps for 230 V, and Franklin’s control boxes come in 115 V and 230 V versions. Goulds’ manual warns that failing to disconnect and lock out power before maintenance can cause shock, burns or death. Franklin’s control box checks are done with the power on, and the manual’s first line is a warning that contact with hazardous voltage could cause death or serious injury.

Ground rules for a homeowner:

• Reset a breaker or swap a fuse, yes. Open the control box or pressure switch cover with power on, no.
• Turn the breaker off and confirm the pump is dead before touching the pressure switch or its tubing.
• Never run a jet pump dry. Goulds says doing so damages the pump and voids the warranty.
• On 2-wire submersibles, wait before restarting. Franklin notes that restarting within about 5 seconds of cutting power can trip the motor overload.

Start here: what is the pump doing?

Go to the pressure tank and watch the gauge while someone opens a faucet.

• Gauge falls to the cut-in pressure, nothing clicks, no hum → the pump does not start. Go to the next section.
• The switch clicks on and you hear the pump, but pressure won’t climb or the pump never shuts off → the pump runs but delivers little water.
• The pump clicks on and off every few seconds → the pump starts too often (short cycling).
• The breaker trips or the pump runs a while and stops → the motor runs but its overload protector trips.

Pump does not start

Breaker or fuse

Franklin’s first two causes are no power or incorrect voltage, and blown fuses or tripped breakers. Reset the breaker once. If it trips again immediately, stop; a breaker that won’t hold points to a wiring fault, a failed motor, or a bound pump (Franklin says amp draw on a sand-bound pump runs 3 to 6 times normal until the overload trips). Measuring voltage, which must be within ±10% of the motor rating, is a meter job.

Pressure switch

The pressure switch is the gray box on a small pipe near the tank. Franklin lists a damaged pressure switch as a cause of a pump that won’t start, because poor contact at its points can drop the voltage below line voltage. With power off, a pro or a confident homeowner can look at the contacts. Burned or pitted points mean cleaning or replacing the switch.

Also look at the small pipe (the nipple or tube) the switch sits on. Goulds lists a plugged pressure switch among the causes of a pump that runs and won’t shut off. Sediment or iron in that fitting can stop the switch sensing the true system pressure. Cleaning it means draining pressure and removing the switch, so do it with the breaker off.

Control box (3-wire submersibles)

If your submersible has a separate control box on the wall, it holds the starting capacitor and relay. Franklin’s AIM manual says:

• A failed start capacitor or an open relay shows up as the red motor lead not drawing a momentary surge at start-up.
• Relay or switch failures cause the red-lead current to stay high and the overload to trip.
• Ohmmeter tests on capacitors, done with power off, are not conclusive, because a capacitor can test good and still have lost capacitance.

Those are amp-clamp and ohmmeter tests on a live box, which is pump-pro territory. One thing you can check: Franklin says the box must not be hot to the touch, and direct sunlight or another heat source can trip its protectors. A box mounted in the sun should be shaded, ventilated or moved.

Pump runs, but little water or it won’t shut off

Low water level or a low-yield well

Franklin lists a low water level as a cause of a pump that runs continuously: the pump may be exceeding the well’s capacity. Its fix is to shut the pump off and let the well recover, then have the static and pumping levels checked. A pro may throttle the pump or lower it, but not if sand could clog it. If water comes back after the pump has rested, and the problem repeats in dry weather or after heavy use, suspect the well, not the pump.

Leaks, a worn pump, or a stuck check valve

Franklin’s other causes for continuous running are a leak in the system, a worn pump, a loose coupling or broken shaft, a blocked intake screen, a check valve stuck closed, and a control box malfunction. One diagnostic tip from the manual: a worn pump looks like a drop-pipe leak or low water. If the pump shuts off after the pressure switch setting is reduced, worn parts may be the cause. All of these mean pulling the pump.

Jet pumps: lost prime or suction leaks

For a jet pump delivering little or no water, Goulds’ causes are a pump not primed or an air leak in the suction pipe; plugged suction or discharge; low voltage; a worn or plugged impeller or jet; system head too high; and excessive suction lift. Re-priming is a homeowner job if you follow the manual’s steps. A suction leak that keeps losing prime usually needs a pro.

Pump starts too often (short cycling)

Franklin’s four causes are a pressure switch problem, a check valve stuck open, a waterlogged tank, and a leak. Goulds adds a defective foot valve, a pump more than 5 ft from the tank, and high-friction valves between pump and tank. Franklin also notes that a waterlogged tank causes rapid cycling severe enough to make the overload protector trip.

The tank is the easiest of these to test. Turn off the pump, drain the system, and press the air valve. Water instead of air means a failed diaphragm. Amtrol lists rapid cycling and low system pressure as the symptoms of a tank that needs replacement. See well pressure tank replacement.

Troubleshooting table

Sources: Franklin AIM manual System Troubleshooting; Goulds IM102R11 troubleshooting.

When to call a pump pro

Call a licensed pump installer if the breaker trips again after one reset, if any check needs a meter on live terminals, if the control box is involved, or if the pump runs without building pressure after the well has rested. Call one, too, if you hear water hammer or the pump spins backward after it stops, which Franklin ties to a missing or failed check valve. Ask the installer to run Franklin’s preliminary tests (voltage, amps, insulation and winding resistance) before pulling anything. Our well pump replacement cost guide explains what a pull and replacement involves, and the well pumps guide covers pump types if you end up replacing it.

Other troubleshooting guides: water softener problems.