What does the Worcester Bosch Greenstar Si F91 fault code mean?
The F91 fault code on the Worcester Bosch Greenstar Si indicates that there are faulty system settings that may prevent the boiler from operating correctly. This could be due to incorrect configuration or settings that need to be adjusted for optimal performance.
Common Causes
- Incorrect Temperature Settings: The boiler may have been set to an inappropriate temperature, leading to operational issues.
- Faulty Control Panel: A malfunction in the control panel can result in incorrect system settings being displayed or applied.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer to address this issue, as incorrect adjustments can lead to further complications or safety hazards. DIY fixes may not resolve the underlying problem.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F91 fault code could be around £120 to £200, depending on whether a control panel replacement is needed or if simple adjustments can be made. This cost reflects the complexity of diagnosing and rectifying system settings.