What does the Worcester Bosch Greenstar Si F31 fault code mean?
The F31 fault code indicates a flue gas temperature fault, which suggests that the boiler is unable to properly monitor or control the temperature of the flue gases. This can lead to inefficient operation and potential safety risks if not addressed promptly.
Common Causes
- Blocked Flue: A blockage in the flue system can prevent proper venting of exhaust gases, causing temperature readings to rise.
- Faulty Temperature Sensor: A malfunctioning temperature sensor may provide incorrect readings, leading the boiler to trigger the F31 fault code.
Can I fix it myself? (DIY)
It is strongly advised to call a Gas Safe Engineer for this issue, as it involves gas and electrical components that can be dangerous if handled improperly. Attempting to fix it yourself may void warranties and compromise safety.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving an F31 fault could range from £150 to £300, depending on whether the issue is a blocked flue or a faulty sensor. If a sensor replacement is required, the cost may be on the higher end due to parts and labour.