Start with the basics: pressure gauge and flow

The most direct way to test a well pump is to measure two things: the pressure it builds and the volume of water it delivers. You need a pressure gauge that screws onto a hose bib (outdoor faucet) on your pressure tank, and you need to time how long it takes to fill a bucket. A working pump typically builds 40 to 60 pounds per square inch (PSI) of pressure, though your system may be set differently. If the gauge reads below 30 PSI or above 70 PSI, the pump or the pressure switch is not working as it should.

To measure flow, turn on an outdoor faucet fully and time how many gallons come out in one minute. A household pump usually delivers 5 to 15 gallons per minute depending on the well depth and pump size. If flow drops suddenly or the pressure swings wildly between high and low, the pump may be losing prime, the check valve may be stuck, or the pump itself may be wearing out. Write down what you see — a baseline reading now makes it easier to spot trouble later.

Key Takeaways

  • A pressure gauge on your tank shows whether the pump is building pressure correctly; normal range is 40 to 60 PSI for most household systems.
  • Timing how long it takes to fill a bucket tells you whether the pump is delivering the flow rate it should, usually 5 to 15 gallons per minute.
  • Pressure that cycles on and off too often, or water that sputters and stops, usually means the pump has lost prime or the check valve is stuck.
  • A pump that runs constantly without building pressure, or one that hums but does not deliver water, points to a failed motor or internal seal.
  • Listening for unusual noise — grinding, squealing, or a high-pitched whine — can catch bearing wear or cavitation before the pump fails completely.

Listen for sounds that signal wear

A healthy pump is relatively quiet. A grinding or squealing noise usually means the bearings are wearing out and the pump will fail within weeks or months. A high-pitched whine or chirp often signals cavitation — the pump is trying to pull water from a level that is too low, or the intake line is partially blocked. A loud clunking or banging sound when the pump starts or stops can mean the check valve is stuck or the pressure tank has lost its air charge.

Stand near the pump and listen while it runs, then listen again when it shuts off. If you hear anything other than a steady hum, write it down and note when it happens — during startup, during normal run, or only when demand is high. These details help a pump technician diagnose the problem faster and more accurately than a vague "it sounds wrong."

Check whether the pump loses prime

A pump that loses prime will not deliver water even though it runs. Prime means the pump chamber is full of water; without it, the pump cannot create suction. If you turn on a faucet and water sputters out in bursts, or if the pump runs for a few seconds then stops, the pump may be losing prime between cycles.

To test this, turn off the pump at the breaker and open the highest faucet in the house. If water drains back into the well instead of staying in the line, the check valve (which should prevent backflow) is leaking. If the pump primes fine when you first start it but loses prime after a few hours of sitting idle, the check valve is likely the culprit. A leaking check valve is cheaper to replace than a pump, so this test is worth doing before you assume the pump itself has failed.

Watch the pressure tank for signs of trouble

The pressure tank stores water under air pressure so the pump does not have to run every time you turn on a faucet. If the pump cycles on and off more than five or six times per minute, the tank may have lost its air charge, or the pump may be leaking water back into the well. A tank that is waterlogged (completely full of water with no air cushion) will cause the pump to short-cycle and wear out faster.

Feel the top of the tank — it should be warm or hot if the pump has been running, and cool or cold if it has been idle. If the entire tank is hot all the time, the pump is running constantly, which means it is not building pressure or the tank is not holding pressure. Tap the tank with your knuckles from top to bottom; the sound should change from a hollow ring at the top (air) to a dull thud lower down (water). If the entire tank sounds dull, the air charge is gone and the tank needs to be serviced or replaced.

Test the pressure switch

The pressure switch tells the pump when to turn on and off. If the pump runs constantly without building pressure, or if it never turns on at all, the switch may be stuck or out of adjustment. You can test it by turning off the pump breaker, opening a faucet to drain the tank, then turning the breaker back on. The pump should start automatically once pressure drops below the switch's "on" setting, usually around 30 to 40 PSI.

If the pump does not start, the switch may be faulty. If the pump starts but runs past the point where it should stop (usually 50 to 60 PSI), the switch may be stuck in the "on" position. A pressure gauge reading will confirm this. Pressure switches are inexpensive and relatively straightforward to replace, so if your test points to the switch, that is usually good news — it is not the pump itself.

Check the electrical connection and breaker

Before you assume the pump has failed, verify that power is reaching it. Look at the breaker in your electrical panel — if it is tripped (switched to the middle or off position), flip it back to on. If it trips again when ready, there is a short in the pump or the wiring, and you should not try to restart it; call a technician.

If the breaker stays on but the pump does not run, check the disconnect switch near the pump itself. Some systems have a separate switch that can be turned off for maintenance. Make sure it is in the on position. If power is reaching the pump but it still will not start, and you hear a humming sound when you turn it on, the motor may be stuck or the capacitor (which helps start the motor) may have failed. A stuck motor will trip the breaker if you keep trying to force it to start, so stop and call for help.

Know when to call a technician

If your pressure gauge reads zero and stays there, the pump is not building pressure at all. If the pump runs but delivers no water, or if it delivers water for a few seconds then stops, the pump has likely failed internally. If you hear grinding or squealing that does not go away after a few seconds, the bearings are worn. If the pump hums but does not turn, the motor is stuck. Any of these signs means the pump needs professional service or replacement.

You can also test by turning off the breaker, waiting five minutes, then turning it back on. If the pump starts and runs normally for a while, you may have a pressure switch or tank issue, which is often cheaper to fix. If the pump fails to start again, or if it starts but when ready loses pressure, the pump itself is the problem. A well pump technician can run more detailed tests — checking amperage draw, inspecting the motor windings, and testing the pump's internal seals — to confirm whether repair or replacement makes sense.

Frequently Asked Questions

What PSI should my well pump be set to?

Most household systems are set to turn on at 30 to 40 PSI and turn off at 50 to 60 PSI. Your specific setting depends on your tank size and how much water you use. Check the label on your pressure tank or pressure switch to see the recommended range, or ask your pump technician what your system should be.

Why does my pump run all the time?

Constant running usually means the pump is not building pressure, the pressure tank has lost its air charge, or the pump is leaking water back into the well through a faulty check valve. A pressure gauge will tell you whether the pump is actually building pressure. If it is not, the pump or check valve has failed. If pressure is building but the pump keeps running anyway, the pressure switch or tank is the problem.

Can I replace a pressure switch myself?

A pressure switch is a straightforward mechanical device, and many homeowners can replace one if they are comfortable working with basic tools and turning off the breaker. The switch screws onto the pump or pressure tank. You will need to drain the system first and match the new switch to the old one's pressure range. If you are unsure, a technician can do it in under an hour.

How often should I test my well pump?

Check your pressure gauge and flow rate once or twice a year, especially before winter or before heavy-use seasons. Listen for unusual sounds every time you are near the pump. If you notice any change in pressure, flow, or noise, test again right away. Regular checks help you catch small problems before they become expensive failures.

What does it mean if water sputters from the faucet?

Sputtering usually means air is in the line, which happens when the pump loses prime or the check valve is leaking. Turn off the pump, open the highest faucet in the house, and see if water drains back into the well. If it does, the check valve needs replacement. If water stays in the line, the pump may need to be reprimed or the intake line may be partially blocked.