What does the Worcester Bosch Greenstar Si F23 fault code mean?
The F23 fault code indicates a flame failure in the Worcester Bosch Greenstar Si boiler, meaning the boiler is unable to detect a flame when it attempts to ignite. This can lead to the boiler shutting down to prevent unsafe operation.
Common Causes
- Blocked Flue: A blockage in the flue system can prevent proper ventilation, leading to flame failure.
- Faulty Ignition Electrode: If the ignition electrode is damaged or dirty, it may not create a spark to ignite the gas.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any gas or electrical issues. However, you can check the boiler pressure and reset the boiler if it is low or has tripped.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F23 fault could be around £150 to £250, depending on whether the issue is a simple reset or requires replacement of parts like the ignition electrode or flue components.