What does the Worcester Bosch Greenstar Si F27 fault code mean?
The F27 fault code on the Worcester Bosch Greenstar Si indicates a problem with the boiler’s pump, which is responsible for circulating water throughout the heating system. This fault can lead to inadequate heating and potential overheating of the boiler if not addressed promptly.
Common Causes
- Blocked Pump Impeller: Debris or scale buildup can obstruct the pump impeller, preventing it from functioning properly.
- Electrical Fault: Issues with the electrical supply to the pump, such as a blown fuse or faulty wiring, can cause the pump to fail.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any repairs related to the pump, as working on gas appliances can be dangerous. However, you can check the boiler pressure and reset the boiler if necessary, following the manufacturer’s instructions.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the F27 fault, including parts and labour, is around £150 to £250. This cost reflects the price of a replacement pump and the expertise required for installation by a qualified engineer.