Applicable Systems
Greenstar GB162
Symptoms
The boiler reports an expansion vessel fault. The expansion vessel is not absorbing system pressure changes.
Possible Causes
- Vessel diaphragm ruptured
- Vessel air charge lost or too low
- Vessel water-logged from diaphragm failure
Troubleshooting Steps
- Step 1: Check the vessel air charge pressure
Pressure is at the correct value - Step 2: Test the diaphragm for integrity
Diaphragm is intact - Step 3: Replace the vessel if the diaphragm has failed
New vessel absorbs pressure changes
How to Reset
To reset: Repair or replace the expansion vessel, then clear the alarm.
Source: Worcester Bosch Boiler Manual, Worcester Bosch Group
Category: Home Boiler