What a well pump test tells you

A well pump test measures whether your pump is delivering water at the right pressure and volume. The test answers three basic questions: Is water actually coming out? Is it coming out at normal pressure? And is the flow steady, or does it sputter and stop? You can run most of these checks yourself with tools you already have at home.

Testing your pump regularly — roughly once a year — catches problems before they leave you without water. A pump that fails suddenly often means a week without running water while you wait for a service call. A pump that shows warning signs gives you time to schedule a repair on your own timeline.

Key Takeaways

  • A basic pressure test uses a gauge screwed onto your pressure tank and takes five minutes; normal household pressure is 40 to 60 pounds per square inch.
  • Flow tests measure how many gallons per minute your pump delivers by timing how long it takes to fill a bucket, and a drop below your pump's rated capacity signals wear or a clogged intake.
  • Pressure that won't build, water that comes out brown or cloudy, or a pump that cycles on and off every few seconds all point to different problems that need different fixes.
  • You can test pressure and flow yourself, but diagnosing the cause and fixing it usually requires a well service technician with specialized equipment.

Testing water pressure with a gauge

The easiest test is a pressure check. Your well system has a pressure tank — a metal cylinder usually in your basement or pump house — that stores pressurized water. On top of that tank is a valve that looks like a tire valve on a car. Screw a pressure gauge (available at any hardware store for $10 to $20) onto that valve.

Read the gauge while the pump is running and water is being used. Normal household pressure is between 40 and 60 pounds per square inch (psi). If your gauge reads below 40 psi, water will dribble from your shower and fill slowly. If it reads above 60 psi, you risk damage to pipes and fixtures. Write down the number and check it again in a few weeks — a steady reading means the pump is holding pressure correctly.

If pressure climbs above 60 psi or won't rise above 20 psi, the pump or tank has a problem. A pressure that swings wildly — jumping from 30 to 70 psi in seconds — usually means the tank's air bladder has failed and needs replacement. These are jobs for a well service technician, not a DIY fix.

Measuring water flow from your pump

A flow test tells you how many gallons per minute your pump is actually delivering. Turn off all water use in the house — no showers, no laundry, no toilets flushing. Go to an outdoor faucet or the lowest tap in your house and turn it on fully. Place a bucket underneath and time how long it takes to fill a 5-gallon bucket.

If the bucket fills in 30 seconds, your flow is 10 gallons per minute. If it takes 60 seconds, your flow is 5 gallons per minute. Most household pumps deliver between 5 and 15 gallons per minute, depending on the pump size and your well's water level. Check your pump's nameplate — usually bolted to the pump itself or mounted on the pressure tank — to see what flow rate it's rated for.

A flow rate that's dropped noticeably from what you remember, or one that's well below the pump's rated capacity, suggests the pump is wearing out or the intake screen is clogged with sediment. A well service technician can pull the pump and inspect it, or clean the intake if that's the problem.

Checking for pressure tank problems

The pressure tank stores water under pressure so your pump doesn't run every time you turn on a faucet. Over time, the air bladder inside the tank can fail, causing the pump to cycle on and off constantly — sometimes every few seconds — even when you're not using water. This is called short cycling and it wears out the pump quickly.

To test the tank, turn off the pump and open a faucet to drain the system completely. Then feel the top of the tank with your hand. It should be warm or hot near the bottom (where water sits) and cool near the top (where air sits). If the entire tank is the same temperature, the bladder has likely failed and the tank is full of water instead of air.

You can also listen: a healthy tank is quiet. A tank with a failed bladder makes a hissing sound when the pump runs, because air is escaping. If you hear hissing or the pump cycles every few seconds, the tank needs replacement — this is a job for a licensed well technician.

Signs that your pump needs professional testing

Some problems you can spot without equipment. If water comes out brown, orange, or cloudy, sediment is getting into your lines — either from a failing pump seal or from the well intake drawing from the bottom. If water smells like rotten eggs, hydrogen sulfide gas is present, which points to bacteria in the well or a corroded pump component. If water tastes salty or metallic, minerals are building up or the pump is pulling from a contaminated zone.

Sputtering water that comes and goes, or a pump that hums but doesn't deliver water, means the pump has lost prime — it's full of air instead of water. A pump that won't start at all, even when you flip the breaker off and back on, has an electrical problem. None of these are tests you can fix yourself; they all require a service call.

When to call a well service technician

Call a technician if your pressure gauge reads consistently below 30 psi or above 80 psi, if your flow rate has dropped by more than 25 percent from normal, or if the pump cycles on and off more than once per minute. Also call if you see any of the warning signs above — brown water, sputtering, no water at all, or a pump that won't start.

A well service technician has a submersible pump puller — a tool that costs several thousand dollars — to safely remove your pump from the well. They can inspect the pump seal, check the intake screen, test the pressure switch, and diagnose electrical problems. They can also perform a well water test to check for bacteria, nitrates, and other contaminants that a straightforward visual or smell test can't catch.

Most service calls run between $150 and $300 for diagnosis and a pressure tank inspection. Pump repair or replacement costs more, but catching a problem early usually means a simpler, cheaper fix than waiting until the pump fails completely.

Keeping records of your pump tests

Write down the date, the pressure reading, and the flow rate each time you test. Keep these notes in a folder with your pump's manual and any service records. Over months and years, a pattern emerges: pressure that slowly drifts down, flow that gradually decreases, or a tank that needs air added more often all signal that maintenance is coming due.

If you ever need to call a technician, having these records saves time and money. The technician can see exactly when the problem started and how fast it's progressing, which helps them diagnose the cause and recommend the right fix. It also protects you if you ever sell the house — a record of regular testing and maintenance shows the next owner that the well system has been cared for.

Frequently Asked Questions

What's the difference between a pressure test and a flow test?

A pressure test measures how hard the water is being pushed through your pipes (measured in psi). A flow test measures how much water is coming out per minute. You need both: high pressure with low flow means the pump is struggling, and low pressure with good flow means the tank or pressure switch has failed.

Can I test my well pump if I have a bladder tank?

Yes, the same pressure gauge test works. Screw the gauge onto the valve on top of the tank and read it while the pump is running. A bladder tank should maintain 40 to 60 psi just like any other pressure tank.

How often should I test my well pump?

Once a year is a good routine — pick the same month each year so you remember. If you notice changes in water pressure, flow, or quality between tests, test again right away. A pump that's working normally won't show big changes from month to month.

What does it mean if my pump pressure keeps dropping?

Pressure that slowly drops over days or weeks usually means the pressure tank's air bladder is leaking. Pressure that drops suddenly during use means a leak in your pipes or a failing check valve. Both need a technician to diagnose and fix.

Is brown water from my well pump dangerous?

Brown water usually means sediment, which isn't toxic but can clog fixtures and taste bad. However, sediment can also indicate a failing pump seal or contamination from the well itself. Have your water tested by a lab to rule out bacteria or chemicals before you assume it's just rust.