Applicable Systems
Lochinvar Knight Boiler (SMART SYSTEM Control)
Symptoms
The boiler reports a circulator pump interlock fault. The pump interlock circuit is not proving pump operation.
Possible Causes
- Circulator pump not running
- Pump interlock relay fault
- Interlock wiring damaged or disconnected
Troubleshooting Steps
- Step 1: Verify the circulator pump is running
Pump operates correctly - Step 2: Test the pump interlock relay
Relay operates correctly - Step 3: Check the interlock wiring
Wiring is intact and connected
How to Reset
To reset: Restore the pump interlock, then clear the alarm.
Source: Lochinvar Boiler Manual, Lochinvar Corporation
Category: Boiler