What does the Glow-worm Flexicom F78 fault code mean?
The F78 fault code on a Glow-worm Flexicom boiler indicates a software issue within the boiler’s control system. This can result in the boiler being unable to operate correctly, leading to heating and hot water failures.
Common Causes
- Software Corruption: This can occur due to power surges or improper updates, leading to malfunctioning control logic.
- Faulty Control Board: A defective control board may not process commands correctly, triggering the F78 fault code.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer for this issue, as it involves the boiler’s software and control systems, which require professional expertise to diagnose and repair safely.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F78 fault code is around £150 to £300, depending on whether a software update or control board replacement is needed. This cost reflects the complexity of the issue and the need for professional service.