K-Rain Pump Start Relay Clicks On Then Off – Voltage Test Needed

Intermittent Relay Failure Now Permanent

An older K-Rain pump start relay clicks on for a few seconds then clicks off, regardless of which zone is selected. The problem has become consistent after being sporadic.

Voltage Diagnostic Procedure

1. With the controller running a zone, measure AC voltage at the controller's COM and MV/PUMP terminals. Should be 23–27 VAC.
2. Disconnect the MV/PUMP wire and measure again. If voltage is steady in both tests, the issue is the relay or its wiring.
3. If voltage is intermittent at the controller, the controller may be faulty.

Most Likely Cause

A loose connection at the relay terminals or a failing relay coil. Inspect and tighten all connections at the relay. If connections are solid, replace the pump start relay.