Why Your Well Water Pressure Drops and What You Can Do About It

Low well water pressure usually comes from one of three places: a broken pressure tank, a clogged filter or screen, or a pump that is failing. You can fix the first two yourself in an afternoon. A failing pump requires a professional, but knowing which problem you have saves you money on service calls.

Start by checking your pressure gauge — most well systems have one mounted on the tank or near the pump. If the gauge reads below 40 pounds per square inch (psi), your system is underperforming. Write down the number. Then move to the pressure tank.

Key Takeaways

  • A waterlogged pressure tank is the most common cause of low pressure and can be fixed by draining and refilling it with air using a bicycle pump or compressor.
  • Sediment buildup in your well screen or the filter between the well and house will reduce pressure; cleaning or replacing the screen takes two to four hours.
  • If pressure drops suddenly after years of normal flow, the pump itself may be failing and will need professional replacement.
  • Pressure should sit between 40 and 60 psi when the pump is off; if it drops below 20 psi, the tank air charge is gone and needs restoration.

Restoring Air Pressure in Your Pressure Tank

A pressure tank holds both water and compressed air. The air acts as a cushion, pushing water out when you open a faucet. Over time, the air charge leaks out or the tank fills with water instead of maintaining the air-water balance. When this happens, the pump runs constantly and pressure stays low.

To fix it, turn off the pump at the breaker. Open a faucet inside the house to drain water from the tank until nothing comes out. Then locate the air valve on top of the tank — it looks like a car tire valve. Use a bicycle pump or air compressor to add air until the gauge reads 38 psi (slightly below your system's cut-in pressure, which is usually 40 psi). Turn the pump back on. Pressure should now climb to 60 psi and hold steady.

If pressure drops again within a few days, the tank has a leak inside and needs replacement. If it holds steady for weeks, you have fixed the problem. Some tanks develop slow leaks over years; you may need to add air once or twice a year.

Cleaning or Replacing Your Well Screen

The well screen sits at the bottom of your well casing and prevents sand and sediment from entering the pump. Over years, fine particles build up on the screen surface, restricting water flow. Pressure drops gradually as the screen clogs.

If your well is shallow — less than 25 feet deep — you may be able to pull the screen yourself. Turn off the pump, unscrew the well cap, and use a pipe wrench to unscrew the casing. Pull the pipe and screen straight up. Rinse the screen with clean water from a hose, scrubbing gently with a soft brush. If the screen is cracked or heavily corroded, replace it with a new one of the same size. Screw everything back together, turn the pump on, and check pressure.

For deeper wells, or if you are not comfortable working with the casing, hire a well contractor. Pulling a deep well screen requires special equipment and can damage the casing if done wrong. A contractor will charge between $300 and $800 depending on depth and whether the screen needs replacement.

Checking and Replacing Filters Between Your Well and House

Many well systems have a sediment filter or cartridge filter installed in the line between the well and the house. This filter catches particles the well screen missed. A clogged filter will drop pressure throughout your whole house.

Locate your filter housing — it is usually a cylindrical tank near the pressure tank or in the basement. Look for a pressure gauge on the housing itself. If it reads more than 10 psi higher than your system pressure gauge, the filter is clogged. Turn off the pump, unscrew the filter bowl (use a filter wrench if it is tight), and pull out the cartridge. Hold it up to a light. If you cannot see light through it, it is clogged.

Replace the cartridge with a new one of the same size and micron rating — the rating is printed on the old cartridge. Screw the bowl back on hand-tight, then turn the pump on. Pressure should improve when ready. Most sediment cartridges last six months to two years depending on how much sediment is in your well.

When the Pump Itself Is Failing

If pressure was normal for years and then dropped suddenly, or if you have restored the tank air charge and cleaned the screen but pressure is still low, the pump may be wearing out. A failing pump loses its ability to push water up from the well, even though it runs.

You will notice the pump running more often than usual, or running constantly. The pressure gauge may climb slowly to 50 or 55 psi instead of reaching the normal 60 psi. Water may sputter from faucets or the shower pressure may be weak even though the gauge reads normal.

Pump replacement requires a licensed well contractor. The cost ranges from $800 to $2,500 depending on well depth, pump size, and whether the old pump is stuck in the casing. Get quotes from at least two contractors before deciding. Ask whether they will pressure-test the new pump before leaving — a good contractor will.

Adjusting Your Pressure Switch Settings

Your pressure switch tells the pump when to turn on and off. The factory setting is usually 40 psi on and 60 psi off. If your pressure is lower than it should be, the switch may have drifted or been adjusted incorrectly.

Locate the switch — it is a box mounted on the pressure tank or nearby pipe. It has two nuts on top. Before touching anything, write down the current pressure reading on your gauge. The larger nut controls the cut-in pressure (when the pump starts). The smaller nut controls the range (the difference between on and off). Turn the larger nut clockwise one-quarter turn to raise the cut-in pressure by about 2 psi. Wait 30 seconds and check the gauge. Repeat until pressure reaches 40 to 50 psi. Do not exceed 60 psi on the cut-in, or the pump will run too hard.

If you are not comfortable adjusting the switch, a well contractor can do it in 15 minutes for a service call fee. Adjusting the switch is a temporary fix if the real problem is a failing tank or pump — it masks the problem rather than solving it.

Frequently Asked Questions

How do I know if my pressure tank is waterlogged?

A waterlogged tank feels heavy and full when you shake it, and the pump runs constantly even when no water is being used. The pressure gauge will drop quickly after the pump shuts off, falling below 20 psi within minutes. Draining and re-pressurizing the tank with air will fix it temporarily; if the problem returns within weeks, the tank has an internal leak and needs replacement.

Can low well water pressure damage my appliances?

Pressure below 30 psi can damage dishwashers and washing machines, which need at least 20 psi to function properly. Tankless water heaters often shut down below 20 psi. Low pressure also causes the pump to run more often, wearing it out faster. Fixing the pressure protects your appliances and extends pump life.

What pressure should my well system maintain?

Most residential well systems are set to cut in at 40 psi and cut out at 60 psi. This means the pump turns on when pressure drops to 40 and shuts off when it reaches 60. Some systems use 30/50 or 50/70 settings depending on the pump and tank size. Check your pressure switch label or ask your well contractor what your system is set for.

Is it safe to add air to the pressure tank myself?

Yes, adding air to the tank is safe if you follow the steps: turn off the pump first, drain the tank completely, and use a bicycle pump or standard air compressor. Do not use a high-pressure industrial compressor, which can over-pressurize the tank. If you are uncomfortable with the process, a well contractor can do it in 30 minutes.

Why does my well pressure drop at night when no one is using water?

Pressure should hold steady at night. If it drops, the pressure tank air charge is low, or there is a slow leak in the plumbing. Check the tank air pressure with a gauge. If it is below 35 psi, restore it. If pressure still drops after you restore the air charge, you have a leak in a pipe or fitting — listen for hissing sounds near the tank and pressure lines, or call a plumber to pressure-test the system.