What does the Worcester Bosch Greenstar i F66 fault code mean?
The F66 fault code indicates a problem with the system pressure relief, which may be due to excessive pressure in the system or a malfunctioning pressure relief valve. This can lead to potential safety issues and requires immediate attention.
Common Causes
- Excessive System Pressure: If the boiler’s internal pressure exceeds the recommended levels, it can trigger the F66 fault code.
- Faulty Pressure Relief Valve: A malfunctioning or blocked pressure relief valve may fail to release excess pressure, causing the fault to appear.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer to diagnose and repair this issue, as it involves gas and safety components. Attempting to fix it yourself may lead to further complications or safety hazards.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F66 fault code is around £150 to £250, depending on whether the pressure relief valve needs replacement or if adjustments to the system pressure are required.