What does the Glow-worm Flexicom F77 fault code mean?
The F77 fault code on the Glow-worm Flexicom indicates a firmware issue within the boiler’s control system. This can prevent the boiler from operating correctly and may require a reset or firmware update to resolve.
Common Causes
- Corrupted Firmware: The firmware may have become corrupted due to a power surge or improper installation.
- Software Glitch: A temporary software glitch can occur, leading to the F77 fault code being displayed.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves the boiler’s internal software and may require specialized tools and knowledge to rectify safely.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F77 fault code is around £150 to £250. This includes the cost of a technician’s visit and potential firmware updates or resets.