How to Fix / Troubleshooting

Safety: Turn off power and close isolation valves before removing any pump. Hot water can cause burns.

Steps:

1. Listen and feel for pump operation: On a call for recirculation, the pump should hum and vibrate slightly. If silent, proceed with checks.
2. Check electrical connections: Verify the pump is wired correctly to the Lochinvar pump terminals and that connections are tight.
3. Free a stuck impeller: Close isolation valves, remove the pump motor from the housing, and attempt to spin the impeller shaft with a screwdriver. If seized, replace the pump.
4. Test voltage: With power on and a call for recirc, measure voltage at the pump terminals. If no voltage is present, the control board relay may be faulty and require replacement.

Lochinvar heater shows E020; may be associated with recirculation pump not running.

Possible Causes