Sprinkler Pump Runs But No Water After Check Valve Replacement

After a technician replaced the check valve on a Hydrotek 4000 two-zone system, the pump runs but delivers no water to the sprinklers or the fill hose. The system worked perfectly before the repair.

Two Likely Causes

1. Check valve stuck closed: The new valve may be installed backward or debris is holding it shut.
2. Pump lost prime: A suction leak on the intake side allows air in, breaking prime when the pump stops.

Diagnostic Steps

1. Prime the pump and run it. If it works, the check valve is fine.
2. After shutting off, inspect the suction piping and pump connections for leaks while residual pressure remains (look for water seeping or air bubbles).
3. Verify the check valve arrow points in the direction of flow.

If the pump holds prime but the check valve leaks back, replace the check valve with a quality spring-loaded model.