Waterlogged Pressure Tank Fix

A waterlogged pressure tank causes short cycling and pump failure. Here is how to confirm the diagnosis and fix it — or replace it if needed.

What Is a Waterlogged Pressure Tank?

A waterlogged tank is one where the internal bladder or diaphragm has failed, allowing water to fill the entire tank with no air cushion. Without air, the tank cannot store pressurized water — so the pump must run every time water is used, cycling on and off every few seconds.

How to Test for Waterlogging

  1. Turn the pump off at the breaker.
  2. Open a faucet to release all system pressure to zero — wait until no water flows.
  3. Find the Schrader valve on top of the tank (looks like a tire valve).
  4. Press the center pin with a screwdriver or tire gauge.
  5. Air comes out = tank may be salvageable. Check pre-charge pressure.
  6. Water comes out = bladder has failed. Tank must be replaced.

If Air Comes Out — Check Pre-Charge

Use a tire gauge to check the pre-charge pressure. It should be 2 PSI below your cut-in pressure. For a 30/50 switch: 28 PSI. For a 40/60 switch: 38 PSI. If pressure is low, add air with a bike pump or compressor. Recheck and test the system.

If Water Comes Out — Replace the Tank

A bladder that has failed cannot be repaired. The tank must be replaced. Steps:

  1. Turn off pump breaker.
  2. Release all pressure through a faucet.
  3. Close the shutoff valve between the tank and the house.
  4. Unscrew the tank from its fitting using a pipe wrench.
  5. Thread on the new tank with Teflon tape.
  6. Set pre-charge to 2 PSI below cut-in before reconnecting.
  7. Restore power and test.

💡 Size up when replacing. The most common mistake is buying the same size tank that failed. If your pump was short cycling, the original tank may have been undersized. Use our calculator to get the correct size before purchasing.

Is Your Pressure Tank the Right Size?

An undersized tank causes low pressure, short cycling, and early pump failure. Check yours free in 2 minutes.

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