What does the Worcester Bosch Greenstar Si F75 fault code mean?
The F75 fault code on the Worcester Bosch Greenstar Si indicates an issue with the return settings, often related to the flow temperature being too low or a problem with the system’s water circulation. This can lead to inefficient heating and potential system damage if not addressed.
Common Causes
- Low Water Pressure: Insufficient water pressure can prevent proper circulation, triggering the F75 fault code.
- Blocked Filters or Pipes: Debris or blockages in the system can restrict water flow, causing the boiler to register a fault.
Can I fix it myself? (DIY)
If you are comfortable, check the water pressure and ensure it is within the recommended range (typically 1-1.5 bar). If the pressure is low, you can top it up using the filling loop. However, for any gas or electrical issues, it is crucial to call a Gas Safe Engineer.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F75 fault could range around £150 to £250, depending on whether it’s a simple pressure adjustment or if more extensive work is needed, such as clearing blockages or replacing components.