What does the Glow-worm Ultimate F66 fault code mean?
The F66 fault code on the Glow-worm Ultimate indicates a domestic hot water (DHW) electrical malfunction. This typically points to issues with the wiring or components responsible for the hot water system’s operation.
Common Causes
- Wiring Issues: Damaged or loose wiring connections can disrupt the electrical flow necessary for the DHW system.
- Faulty Components: Malfunctioning sensors or control boards may fail to communicate properly, leading to the F66 error.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer for this issue, as it involves electrical components that can be dangerous to handle without proper training.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F66 fault could be around £150 to £250, depending on whether wiring repairs or component replacements are needed. This estimate includes labour and parts, reflecting the complexity of electrical diagnostics.