Applicable Systems
Greenstar GB162
Symptoms
The boiler reports a safety valve activation. The pressure relief safety valve has opened to discharge excess pressure.
Possible Causes
- System pressure too high from expansion vessel failure
- Safety valve setpoint drifted too low
- Fill valve stuck open over-pressurizing the system
Troubleshooting Steps
- Step 1: Check the system pressure gauge
Pressure is within the normal range - Step 2: Verify the expansion vessel charge and diaphragm
Vessel is charged and functional - Step 3: Check the fill valve operation
Valve closes completely
How to Reset
To reset: Restore normal system pressure, verify the safety valve, then reset.
Source: Worcester Bosch Boiler Manual, Worcester Bosch Group
Category: Home Boiler