If water pressure keeps dropping after the pump stops, either your main house valve is leaking and there is water running in the building, or there is a bad check valve or foot valve and water and pressure are returning to the well. See MAIN WATER SHUTOFF VALVE.
What would cause a well pump to lose pressure?
Causes of loss of well pump prime include more than a bad foot valve. A leak anywhere in the water system from pump and pressure tank, through piping, down to the end of the pipe in the well (foot valve) that lets water out or air into the system can cause loss of pump prime and thus loss of water pressure.
What causes a water pressure tank to lose pressure?
As the water level in the tank drops from household demand, pressure in the tank declines to a preset minimum. The well pump then actuates to pump more water into the tank and restore pressure. An under-inflated air bladder results in lower water pressure output from the tank.
