What does the Glow-worm Ultimate F59 fault code mean?
The F59 fault code indicates a malfunction of the domestic hot water (DHW) sensor in the Glow-worm Ultimate boiler. This issue can prevent the boiler from accurately detecting the temperature of the water, leading to potential heating problems.
Common Causes
- Faulty DHW Sensor: The sensor may be damaged or malfunctioning, causing incorrect readings.
- Wiring Issues: Damaged or loose wiring connections to the DHW sensor can disrupt its functionality.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves electrical components and gas safety regulations. Attempting to fix it yourself could lead to further complications or safety hazards.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the DHW sensor is around £150 to £200, including parts and labour. This is based on the typical cost of the sensor and the time required for a qualified engineer to complete the repair.