Why Is My Well Pump Losing Pressure? 7 Common Causes

Losing water pressure on a well system is frustrating, but it is rarely a mystery. Most pressure problems trace back to the pressure tank, the pressure switch, or a restriction in the system, not a dead pump. Working through the causes in order usually points to the fix, and often a cheap one.

Here are seven common reasons a well pump loses pressure, starting with the easiest to check. If it does come down to the pump, compare replacements in the well pumps collection.

1. A Waterlogged Pressure Tank

This is the most common culprit. A pressure tank uses a cushion of air to hold pressure between pump cycles. When that air charge is lost, the tank becomes waterlogged, the pump short cycles, and pressure swings up and down. Tap the tank: a healthy tank sounds hollow up top and solid at the bottom. A tank that is solid all the way up is waterlogged and needs recharging or replacing.

2. A Failing Pressure Switch

The pressure switch tells the pump when to start and stop. If it is misadjusted, corroded, or has burned contacts, the pump may cut out too early and leave you with low pressure. Switches are inexpensive and a frequent fix. Related controls and pump control panels are worth checking on larger systems.

3. Clogged Filters, Screens, or Sediment

Sediment screens, whole-house filters, and the pump intake can clog over time, especially in wells with sand or iron. A restricted filter chokes flow and drops pressure at every tap. Replace or clean filters on a schedule and rule this out before blaming the pump.

4. A Stuck or Failing Check Valve

A check valve keeps water from draining back down the well between cycles. If it sticks or fails, the pump loses prime and pressure, and you may hear it running more than usual. This is a common issue on older systems.

5. A Leak in the System

A leak in the drop pipe, a fitting, or household plumbing forces the pump to work harder and can drop pressure. If the pump runs when no water is being used, suspect a leak somewhere in the line.

6. A Worn or Undersized Pump

Impellers wear over years of use, especially with sandy water, and a worn pump slowly loses output. A pump that was undersized for the home from the start will also struggle as demand grows. If everything else checks out, the pump itself may be the cause.

7. A Dropping Water Table

In dry seasons, the water level in the well can fall below the pump intake, causing sputtering and lost pressure. This is common with shallow well pumps and may call for lowering the pump or moving to a deep well setup.

Final Thoughts

Work from cheap to expensive: check the tank, the switch, and the filters before assuming the pump has failed. If pressure is still weak, or the pump is old and running constantly, replacement is the smart move. For help choosing the right horsepower, read our Sta-Rite well pump buying guide.

Frequently Asked Questions

Why does my well water pressure keep dropping?

The most common cause is a waterlogged pressure tank, followed by a failing pressure switch or clogged filters. Check those first, then look for leaks or a worn pump.

How do I know if my pressure tank is bad?

Tap the tank. A healthy tank sounds hollow near the top and solid at the bottom. If it sounds solid all the way up, or the pump cycles on and off rapidly, the tank is waterlogged.

Can a bad pressure switch cause low pressure?

Yes. A misadjusted, corroded, or worn switch can shut the pump off too soon, leaving low pressure. Switches are inexpensive and a common fix.

When should I replace my well pump instead of repairing it?

If the tank, switch, and filters are fine but pressure stays weak, or the pump is near the end of its lifespan and running constantly, replacement is usually the better long-term choice.