Why Does My Well Pump Keep Running?
A well pump that won't shut off is one of the most common well system complaints in Southern Maryland — and one of the most misdiagnosed. Here are the six real causes and what each one means for your system.
A pump that runs continuously will overheat, burn out its motor, and drive up your electric bill. If your pump has been running non-stop for more than an hour, shut it off at the breaker and call a plumber.
How a Well Pump Is Supposed to Work
A submersible well pump is controlled by a pressure switch — typically set to turn the pump on at 40 PSI and off at 60 PSI. When you open a faucet, pressure drops, the switch kicks the pump on, and the pump runs until pressure is restored. The pressure tank stores a cushion of pressurized water so the pump doesn't have to cycle on every time you use a small amount of water.
When the pump runs continuously, it means the system can't reach the shutoff pressure — or the switch itself is stuck. Either way, something has failed.
The 6 Most Common Causes
Waterlogged Pressure Tank
This is the #1 cause. The pressure tank contains a rubber bladder that separates the air charge from the water. When the bladder fails, the tank fills completely with water and loses its air cushion. Without that cushion, the system can't hold pressure — so the pump runs constantly trying to build it. You'll often hear rapid short-cycling (pump turning on and off every few seconds) alongside continuous running.
Learn about waterlogged pressure tanks →Pressure Switch Failure
The pressure switch is a small mechanical device that reads system pressure and tells the pump when to start and stop. If the contacts inside the switch corrode or stick in the "on" position, the pump will run regardless of system pressure. This is a cheap fix — pressure switches cost $15–$30 — but it requires shutting off power to the pump first.
A Leak Somewhere in the System
If there's a leak in the pressure tank, the plumbing, a toilet fill valve, or even a dripping faucet, the system slowly loses pressure — and the pump runs to compensate. Check all toilets (a running toilet can lose 1–3 gallons per minute), look for wet spots near the pressure tank, and check under sinks. Even a small leak can keep a pump running continuously.
Low Water Table or Dry Well
During drought conditions — which are increasingly common in Calvert County and Anne Arundel County — the water table can drop below the pump intake. The pump runs but can't draw enough water to build pressure. You may also notice air sputtering from faucets or discolored water. This is a serious situation that may require lowering the pump or drilling deeper.
Low-yield well solutions →Pump Is Undersized for Demand
If your household demand has grown — more people, irrigation, a new bathroom — your pump may simply not be able to keep up. An undersized pump will run continuously during peak use periods trying to meet demand it was never designed for. The fix is usually upgrading to a higher-capacity pump or adding a constant pressure system.
Constant pressure well systems →Failing Pump Motor
A pump motor that's losing efficiency — due to worn impellers, bearing failure, or motor winding degradation — may run continuously because it can no longer build adequate pressure even when the rest of the system is fine. This is typically accompanied by higher electric bills and reduced water pressure throughout the house.
Well pump service & replacement →How to Diagnose It Yourself (Safely)
- Check your pressure gauge — if it's stuck below 40 PSI while the pump runs, pressure isn't building
- Tap the pressure tank with your knuckle — a waterlogged tank sounds solid throughout; a healthy tank sounds hollow in the upper half
- Listen for short-cycling — rapid on/off cycling almost always means a failed pressure tank bladder
- Check all toilets and faucets for leaks — a running toilet can lose enough water to keep a pump running
- Look at your electric meter — a pump running continuously will show noticeably higher consumption
- If you can't identify the cause in 10 minutes, shut the pump off at the breaker and call a professional
Frequently Asked Questions
Is it bad if a well pump runs all the time?
Yes — continuous operation overheats the motor, accelerates wear on bearings and impellers, and significantly shortens pump life. Most pumps are rated for a certain number of starts per hour, not continuous operation.
How much does it cost to fix a well pump that won't shut off?
It depends on the cause. A pressure switch replacement is $100–$200 including labor. A pressure tank bladder replacement is $300–$600. A full pump replacement in Southern Maryland typically runs $1,500–$3,500 depending on depth and pump size.
Can I leave my pump running overnight?
We don't recommend it. Shut the pump off at the breaker until you can get a diagnosis. Running a pump continuously overnight risks burning out the motor — turning a $400 repair into a $2,500 replacement.
Real Job: Waterlogged Pressure Tank — Owings, MD
An Owings homeowner's pump ran every time a faucet was opened. We confirmed a waterlogged pressure tank — the pump was starting hundreds of times per day. A same-day 44-gallon tank replacement restored normal pump cycles and dropped the electric bill the following month.
Read the full project story