Applicable Systems
Lochinvar Knight Boiler (SMART SYSTEM Control)
Symptoms
The boiler reports a relief valve activation. The pressure relief safety valve has opened.
Possible Causes
- System pressure too high from expansion vessel failure
- Relief valve setpoint drift too low
- Fill valve stuck open over-pressurizing
Troubleshooting Steps
- Step 1: Check the system pressure gauge
Pressure is within the normal range - Step 2: Verify the relief valve setpoint
Setpoint has adequate margin above operating pressure - Step 3: Check the fill valve operation
Valve closes completely
How to Reset
To reset: Restore normal pressure, verify the relief valve, then reset.
Source: Lochinvar Boiler Manual, Lochinvar Corporation
Category: Boiler