What does the Glow-worm Ultimate F51 fault code mean?
The F51 fault code on the Glow-worm Ultimate indicates a failure of the domestic hot water (DHW) thermistor. This component is responsible for measuring the temperature of the water, and its malfunction can lead to issues with hot water supply.
Common Causes
- Faulty Thermistor: The thermistor may be damaged or malfunctioning, leading to incorrect temperature readings.
- Wiring Issues: Damaged or loose wiring connections to the thermistor can disrupt its function and cause the fault code to appear.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to address this issue, as it involves gas and electrical components that require professional expertise for safety and compliance.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the DHW thermistor on a Glow-worm Ultimate is around £120. This includes the cost of the part and labour, as the thermistor itself is relatively inexpensive, but professional installation is necessary.