Well Pump Runs Continuously Without Shutting Off

Turn the Pump Off First

6 Causes of a Well Pump That Won't Stop

1. Failed Pressure Switch — Contacts Fused Closed

This is the most common cause. Pressure switch contacts can weld themselves closed from repeated arcing, especially on older switches. When contacts are fused, they cannot open to stop the pump — the pump runs regardless of system pressure. Open the switch cover and inspect the contacts. If they are black, burnt, or fused together, replace the switch immediately ($15-35).

2. Major Water Leak

A significant leak — burst pipe, failed pressure tank fitting, open hose bib — dumps water faster than the pump can pressurize the system. The pump runs trying to catch up but never reaches cut-off pressure. Check all visible plumbing, toilets, outdoor spigots, and the water heater relief valve.

3. Low Well Water Level

During drought or after heavy water use, the well water level can drop below the pump intake. The pump pulls air instead of water and cannot build pressure. Turn off the pump and wait 30-60 minutes. If it builds pressure normally after resting, the well is recovering slowly.

4. Waterlogged Pressure Tank

A completely waterlogged tank provides zero pressure storage. The pump runs and runs trying to build pressure but the gauge barely moves. Test the Schrader valve — water coming out confirms a failed bladder.

5. Pressure Switch Set Too High

If the cut-off pressure is set higher than the pump can actually deliver (e.g. 80 PSI cut-off on a pump that maxes out at 70 PSI), the pump runs forever trying to hit a pressure it cannot reach. Verify the cut-off setting matches the pump's rated shut-off head pressure.

6. Failed Pump Impeller

A worn or broken impeller can no longer move water efficiently enough to build system pressure. The pump runs but pressure barely climbs. If all other causes check out and the pump is 10+ years old, the impeller or entire pump may need replacement.