Applicable Systems
Greenstar GB162
Symptoms
The boiler reports a high system pressure alarm. The system water pressure exceeds the maximum safe level.
Possible Causes
- Fill valve stuck open or overfilled
- Expansion vessel diaphragm failure
- Pressure sensor calibration error
Troubleshooting Steps
- Step 1: Check the system pressure gauge
Pressure is below the maximum - Step 2: Verify the fill valve is closed
Valve is fully closed - Step 3: Check the expansion vessel operation
Vessel absorbs expansion correctly
How to Reset
To reset: Reduce the system pressure to the correct range, then clear the alarm.
Source: Worcester Bosch Boiler Manual, Worcester Bosch Group
Category: Home Boiler