What does the Worcester Bosch Greenstar Si F35 fault code mean?
The F35 fault code on the Worcester Bosch Greenstar Si indicates a problem with the gas valve, which may be preventing the boiler from operating correctly. This issue can lead to the boiler failing to ignite or maintain a flame, affecting heating and hot water supply.
Common Causes
- Faulty Gas Valve: The gas valve may be malfunctioning due to wear and tear or internal failure, preventing it from opening or closing properly.
- Electrical Issues: Problems with the electrical connections or control board can lead to incorrect signals being sent to the gas valve, causing it to fail.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer for any issues related to the gas valve, as working with gas appliances can be dangerous. Attempting to fix it yourself could lead to safety hazards.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for a faulty gas valve on a Worcester Bosch Greenstar Si is around £300 to £400. This includes the cost of the replacement part and labour, reflecting the complexity of the repair and the need for a qualified technician.