What does the Glow-worm Energy F51 fault code mean?
The F51 fault code indicates that the boiler has detected a leak in the domestic hot water (DHW) system. This can lead to reduced efficiency and potential damage if not addressed promptly.
Common Causes
- Leak in DHW pipework: A physical leak in the pipes supplying hot water can trigger this fault code.
- Faulty DHW heat exchanger: A malfunctioning heat exchanger may cause water to leak internally, resulting in the F51 error.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer to diagnose and repair the issue, as working on gas appliances can be dangerous and requires professional expertise.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F51 fault could range from £150 to £300, depending on whether the issue is a simple pipe repair or requires replacement of the heat exchanger, which is more costly.