Why Your Well Pump Pressure Drops and How to Raise It

A well pump loses pressure for a few specific reasons: the pressure tank has lost its air charge, the pump itself is worn, sediment is clogging the system, or the pressure switch settings have drifted. You can raise pressure by recharging the tank, adjusting the pressure switch, cleaning the intake screen, or replacing a failing check valve — most of these are jobs a homeowner can do in an afternoon with basic tools.

The fastest fix is usually the pressure tank. Over time, the air bladder inside absorbs water and loses its cushion. When that happens, the pump runs constantly and pressure stays low. Recharging it takes 20 minutes and costs nothing if you have a bicycle pump or air compressor at home.

Key Takeaways

  • A waterlogged pressure tank is the most common cause of low pressure and can be recharged with an air compressor in under an hour.
  • The pressure switch controls when the pump turns on and off; adjusting it upward raises the pressure the system maintains, but should not exceed the tank's rated pressure.
  • Sediment in the intake screen or check valve blocks flow and mimics low pressure; cleaning or replacing these parts restores normal output.
  • If the pump itself is old or the motor sounds strained, the pump may be failing and will need replacement rather than adjustment.

Recharge Your Pressure Tank

The pressure tank holds air above the water. As the pump runs, it pushes water into the tank, compressing the air. That compressed air pushes back, keeping pressure steady even when the pump is off. When the air bladder fails or leaks, water fills the space where air should be, and pressure drops because there is nothing to push back.

To recharge the tank, first turn off the pump and open a faucet to release pressure. The tank should have a valve on top that looks like a tire valve on a car. Use a bicycle pump or air compressor to add air until the pressure gauge reads about 2 pounds per square inch (psi) below your pump's cut-in pressure — usually around 28 psi if your pump is set to cut in at 30 psi. Do not overcharge; too much air can damage the tank.

If the tank will not hold air after recharging, the bladder has failed and the tank must be replaced. If it holds air for weeks or months before losing pressure again, the bladder is slowly leaking and replacement is coming, but you can recharge it as a temporary fix.

Adjust the Pressure Switch

The pressure switch tells the pump when to turn on and off. It has two settings: the cut-in pressure (when the pump starts) and the cut-out pressure (when it stops). If both are set too low, the system will never build enough pressure. Raising them increases the pressure the pump maintains.

The switch is usually mounted on a pipe near the pressure tank. It has two nuts on top that control the settings. Loosen the larger nut (the cut-out adjustment) by turning it counterclockwise to raise the pressure at which the pump shuts off. A quarter turn raises pressure by about 2 psi. After each adjustment, turn the pump on, let it run until it shuts off, and check the pressure gauge. Stop when you reach the pressure you want.

Do not raise the cut-out pressure above the tank's maximum rated pressure — this is printed on the tank's label. Most residential tanks are rated for 60 to 100 psi. Exceeding the rating risks rupturing the tank. If you need pressure higher than the tank allows, you need a larger or higher-rated tank, not just a switch adjustment.

Clean or Replace the Check Valve

The check valve sits between the pump and the pressure tank. It allows water to flow into the tank but prevents it from flowing backward when the pump shuts off. When sediment, mineral buildup, or debris gets stuck in the valve, water cannot flow freely, and pressure stays low even though the pump is running hard.

To check the valve, listen to the pump. If it runs constantly and sounds strained but pressure does not rise, the check valve is likely blocked. Turn off the pump and locate the check valve — it is usually a brass fitting with a spring inside, mounted horizontally or vertically on the discharge line. Unscrew it by hand or with a wrench and rinse it under clean water. If debris is stuck inside, use a small brush or cloth to clean the internal spring and seat.

Screw the valve back in, turn the pump on, and check the pressure. If pressure still does not rise, the valve spring may be broken and the valve needs replacement. A new check valve costs $15 to $40 and takes 10 minutes to install.

Clear the Intake Screen

The intake screen sits at the bottom of the well and filters out sand and sediment before water enters the pump. Over years of use, the screen clogs with fine sediment, reducing the flow of water into the pump. The pump runs but cannot pull enough water, so pressure stays low.

If your well is shallow (under 25 feet), you may be able to pull the pipe and screen yourself. Turn off the pump, disconnect the discharge line, and use a pipe wrench to unscrew the casing at the well head. Pull the pipe up slowly — it will be heavy and full of water. Once the screen is above ground, rinse it thoroughly under running water and use a soft brush to remove sediment. If the screen is torn or corroded, replace it with a new one of the same size.

For deep wells, this job usually requires a well service company with a pump puller. The cost varies by depth and location, but expect $300 to $800. If your pressure has been dropping gradually over years, a clogged intake screen is a likely cause and cleaning it will restore pressure significantly.

Inspect the Pump for Wear

If you have recharged the tank, adjusted the switch, cleaned the check valve, and cleared the intake screen, but pressure is still low, the pump itself may be failing. Pump wear is not something you can fix at home — the pump will need replacement.

Signs of a failing pump include: the motor sounds strained or makes grinding noises, the pump runs constantly without building pressure, or pressure drops suddenly after years of normal operation. A new submersible pump costs $400 to $1,200 installed, depending on the well depth and pump size. A surface pump costs $300 to $800. Installation usually requires a licensed well contractor.

Before paying for a new pump, confirm that the other fixes above have been tried. Many homeowners replace a pump unnecessarily when the real problem was a waterlogged tank or a blocked check valve.

Frequently Asked Questions

How much air should I put in the pressure tank?

Add air until the gauge reads about 2 psi below your pump's cut-in pressure. If the pump cuts in at 30 psi, aim for 28 psi in the tank. Use a tire pressure gauge to measure. Too much air can damage the tank; too little defeats the purpose of the air charge.

Can I raise the pressure switch above 60 psi?

Only if your tank is rated for it. Check the label on the tank for the maximum pressure rating. Most residential tanks are rated 60 to 100 psi. Never exceed the tank's rating — the tank will rupture and fail suddenly.

Why does my pump run all the time but pressure stays low?

The pump is likely blocked downstream. Check the intake screen for sediment, the check valve for debris, and the discharge line for kinks or clogs. If all are clear, the pump itself may be failing and losing its ability to move water.

How often should I recharge the pressure tank?

A healthy tank should hold its air charge for years. If you are recharging every few months, the bladder is leaking and the tank should be replaced. If you recharge once every year or two, the tank is aging normally and replacement can wait.

Is it safe to adjust the pressure switch myself?

Yes, if you turn off the pump first and make small adjustments. Turn the nut a quarter turn, restart the pump, and wait for it to shut off before checking the pressure. Never force the nut or adjust it more than a half turn at a time.