Symptoms
- Pump turns on and off very frequently, even with small water use
- Pressure gauge swings rapidly between high and low readings
- Tank feels heavy and sounds solid rather than hollow when tapped
- Pump seems to run more than it used to
Likely causes
- CommonRuptured internal bladder in the tankModern tanks use a rubber bladder to separate air from water; once it fails, the tank fills entirely with water.
- CommonLost air charge without a bladder failure (older tank designs)Older non-bladder tanks lose their air cushion gradually and need periodic recharging.
- PossibleFaulty air valve (Schrader valve) on top of the tankThis valve, similar to a tire valve, can leak air out over time even with an intact bladder.
- Less commonTank undersized for the household's water demandA tank too small for the home will cycle frequently even when working correctly.
What to do
- Turn off power to the well pump before doing any work on the tank.
- Close the valve between the tank and the rest of the plumbing, then open a faucet to relieve pressure and drain the tank fully.
- Locate the air valve (Schrader valve) on top of the tank and check its air pressure with a tire gauge.
- Add air with a bicycle or compressor pump to the pressure recommended for your tank (often about 2 psi below the pump's cut-in pressure).
- Close the drain, reopen the tank valve, and restore power to the pump.
- Monitor the pressure gauge and pump cycling over the next few uses to see if it now cycles less frequently and more normally.
- If the tank won't hold air (indicating a ruptured bladder), it needs to be replaced rather than just recharged.
Tools and parts
- Tire pressure gauge
- Air pump or compressor
Well pressure tank (if replacement needed)Search: “well water pressure tank”
When to call a pro
Call a well contractor if the tank won't hold air after recharging, since it likely needs replacement.
Safety
Use caution
Always shut off power to the pump before draining or servicing the tank to avoid the pump running dry.