Why well water pressure drops and what you can do about it

Low water pressure from a well usually means one of three things: the pump is undersized for your household demand, sediment has clogged the system, or the pressure tank has lost its air charge. You can often fix this yourself by checking the pressure tank, cleaning or replacing the well screen, or adjusting the pump's pressure switch. If the well itself is running dry or the pump is failing, you will need a professional well contractor, but many pressure problems are solved with basic maintenance and a trip to the hardware store.

The most common fix is re-pressurizing the pressure tank, which takes about 30 minutes and costs nothing if you already own an air compressor. The second most common is cleaning sediment from the well intake, which takes a few hours and costs under $50. Start with these before calling a contractor.

Key Takeaways

  • A pressure tank that has lost its air charge is the most frequent cause of low well pressure and can be fixed by adding air with a compressor.
  • Sediment buildup in the well screen or intake line reduces flow and can be cleared by backflushing or removing and cleaning the screen.
  • The pressure switch controls when the pump turns on and off; adjusting it upward increases the pressure at which the pump kicks in.
  • If the well itself is producing less water than it used to, the water table may be dropping or the pump may be failing, and you will need a well contractor to diagnose it.
  • Undersized pumps cannot meet peak demand in larger households, and replacing the pump is the only permanent fix.

Check and recharge the pressure tank

The pressure tank stores water under air pressure so the pump does not run every time you turn on a faucet. Over time, the air bladder inside the tank can rupture or the air charge can leak out, leaving the tank full of water but no air cushion. When this happens, pressure drops and the pump cycles on and off constantly. You can test this by turning off the pump and tapping the tank with your knuckles—a healthy tank sounds hollow and metallic in the upper half, and dull and full in the lower half. If the whole tank sounds full, the air charge is gone.

To recharge the tank, first turn off the pump at the breaker. Drain the tank completely by opening the lowest faucet in the house and letting it run until water stops. Once empty, use an air compressor to fill the tank to about 2 pounds per square inch (psi) below your pump's cut-in pressure—usually 28 psi if your pump is set to 40 psi. Use a tire gauge to check the pressure at the small valve on top of the tank (it looks like a car tire valve). Close the valve, turn the pump back on, and check your water pressure at a faucet. This fix often restores pressure to normal within an hour.

Clean or replace the well screen and intake line

Sediment, sand, and mineral buildup in the well screen or intake line choke off water flow even when the pump is working hard. You will notice this if pressure has dropped gradually over weeks or months rather than suddenly. The well screen is a fine mesh at the bottom of the well casing that keeps sand out of the pump. When it clogs, water cannot enter the pump fast enough.

The easiest fix is backflushing: turn off the pump, locate the check valve on the intake line (usually a brass fitting near the pump), and if your system has a backflush port, attach a hose and run water backward through the line for 5 to 10 minutes. If you do not have a backflush port or backflushing does not help, you will need to pull the well screen and clean it by hand or replace it. This requires disconnecting the intake line and raising the screen out of the well—a job that takes a few hours and is easier with a helper. Rinse the screen under running water or soak it in white vinegar overnight to dissolve mineral deposits, then reinstall it. If the screen is cracked or torn, replace it with a new one of the same size.

Adjust the pressure switch to increase pump pressure

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 your pump is set to cut in at 30 psi and cut out at 50 psi, water pressure will never exceed 50 psi. Raising these settings increases the pressure throughout your house.

To adjust the switch, locate it on the pump or pressure tank—it is a small box with two nuts on top and wires running to the pump motor. Turn off the pump at the breaker. Using an adjustable wrench, turn the larger nut clockwise to raise the cut-out pressure (the maximum pressure). A quarter turn usually raises pressure by 5 to 10 psi. Turn the pump back on and check the pressure at a faucet with a pressure gauge. Repeat in small increments until you reach your target pressure, usually 60 to 80 psi. Do not exceed 80 psi, as this can damage fixtures and seals. If you are uncomfortable working with electrical components, a well contractor can make this adjustment in 15 minutes.

Identify whether the pump itself is failing

If pressure is low but the tank is charged, the intake is clean, and the pressure switch is set correctly, the pump may be wearing out. A failing pump loses its ability to move water efficiently, even when running constantly. You will notice the pump running more often than it used to, or hear unusual grinding or squealing sounds.

To test the pump, measure the flow rate: turn on a faucet and time how long it takes to fill a 5-gallon bucket. A healthy well pump should fill it in 30 seconds or less. If it takes longer, the pump is not delivering its rated flow. At this point, you need a well contractor to pull the pump and test it under load. Pump replacement costs $800 to $2,000 depending on the pump size and depth of the well, but it is the only fix if the pump itself has failed.

Rule out a dropping water table or dry well

If the well has always produced good pressure but pressure has dropped over months or years, the water table in your area may be dropping due to drought or heavy use by neighbors. You can test this by turning off the pump and listening at the well cap—if you hear water trickling, the well still has water. If you hear nothing, the well may be running dry.

A well contractor can measure the static water level (the depth of water when the pump is off) and compare it to the original well log, which should be on file with your county. If the water level has dropped below the pump intake, the pump will suck air instead of water, and pressure will fall to zero. The fix is to lower the pump deeper into the well or drill a new well, both of which require professional help. If the water table is dropping due to regional drought, there is no permanent fix until water returns, but a contractor can advise whether lowering the pump is practical.

When to call a well contractor

You can handle pressure tank recharging, screen cleaning, and pressure switch adjustment on your own if you are comfortable with basic tools and electrical connections. Call a contractor if the pump is making unusual noises, if the well is producing no water at all, if you cannot safely access the pressure switch, or if the water table has dropped below the pump intake. A contractor can also pull and test the pump, measure well depth and water level, and determine whether the pump needs replacement or relocation.

Most well contractors charge $100 to $200 for a service call and diagnosis. If they recommend pump replacement or well work, get a second opinion, as these are expensive jobs. Many contractors also offer annual maintenance visits to check pressure, inspect the tank, and catch problems early.

Frequently Asked Questions

How do I know what pressure my pump should be set to?

Most household wells are set to 40 to 60 psi cut-out pressure, which provides adequate flow for showers and washing. Check your pump's nameplate or the original well paperwork for the manufacturer's recommended range. If you cannot find it, 50 psi is a safe starting point for most homes. Higher pressure uses more energy and stresses fixtures.

Can low water pressure damage my pump?

No, but a pump running constantly because pressure is low will wear out faster. If the pressure tank is dead and the pump cycles on and off every few seconds, the motor can overheat. Recharging the tank or fixing the intake line stops this rapid cycling and extends pump life.

What if I recharge the pressure tank and pressure drops again in a few days?

The air bladder inside the tank is likely ruptured and leaking. The tank will need to be replaced, which costs $300 to $800 depending on size. A contractor can confirm this by checking the air pressure again after a few days. Do not attempt to repair the bladder yourself.

Is it safe to adjust the pressure switch myself?

It is safe if you turn off the pump at the breaker first and do not touch the electrical wires. The switch itself is mechanical and adjusting the nuts does not create shock hazard. If you are unsure, a contractor can do it in 15 minutes for a small service fee.

Why does my water pressure drop when I run multiple faucets?

The pump cannot deliver enough water to meet peak demand. This is normal in larger homes or when the pump is undersized. The pressure tank should smooth out these dips by releasing stored water, but if the tank is small or dead, pressure will drop noticeably. Upgrading to a larger tank or pump is the permanent fix.