What does the Glow-worm Ultimate F54 fault code mean?
The F54 fault code on the Glow-worm Ultimate indicates a failure of the domestic hot water (DHW) flow switch. This issue prevents the boiler from detecting water flow, which can disrupt hot water supply.
Common Causes
- Faulty Flow Switch: The flow switch may be defective or stuck, failing to signal the boiler when water is flowing.
- Blocked Pipework: Blockages in the water pipes can prevent proper flow, leading to the flow switch not activating.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and repair this issue, as it involves gas and electrical components that can be dangerous if handled improperly.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for the F54 fault code is around £150 to £250, primarily for the replacement of the flow switch and associated labour. This cost reflects the complexity of the repair and the need for a qualified technician.