Well Pump Losing Prime: Diagnosing a Faulty Check Valve

Pump Pressure Drops, Re‑Primes on Every Start

A well pump that loses prime when idle and re‑primes on each cycle typically has a failed check valve (foot valve) on the suction line. The check valve should hold water in the pipe when the pump stops; if it leaks, the water drains back and the pump must re‑prime.

Diagnosis

• Inspect the suction line for visible leaks.
• If the line is intact, the check valve is the culprit. On a lake/pond intake, the check valve is at the pipe entrance. On a well, it’s in the drop pipe.
• Replace the check valve with a new one rated for your pump’s flow.

Detailed pump and check valve guides are at irrigationtutorials.com.