What does the Glow-worm Ultimate F63 fault code mean?
The F63 fault code on the Glow-worm Ultimate indicates a malfunction with the domestic hot water (DHW) flow switch. This issue typically prevents the boiler from properly detecting water flow, which can disrupt hot water supply.
Common Causes
- Blocked Flow Switch: Debris or mineral build-up can obstruct the flow switch, preventing it from functioning correctly.
- Electrical Fault: A wiring issue or a faulty connection can lead to the flow switch not sending the correct signals to the boiler.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves gas and electrical components that require professional handling for safety reasons.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the F63 fault code is around £150 to £200. This includes the cost of a new flow switch and labour, as it is a common issue that can be resolved relatively quickly by a qualified engineer.