What does the Glow-worm Betacom F31 fault code mean?
The F31 fault code on a Glow-worm Betacom boiler indicates a thermistor fault, which typically means that the temperature sensor is malfunctioning or has failed. This can lead to incorrect temperature readings, affecting the boiler’s ability to operate efficiently.
Common Causes
- Faulty Thermistor: The thermistor may be damaged or have a poor connection, preventing it from accurately measuring temperature.
- Wiring Issues: Damaged or corroded wiring connected to the thermistor can lead to communication failures between the sensor and the boiler’s control board.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and repair the issue, as working with gas appliances can be dangerous. Attempting to fix electrical components without proper training can also pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing a thermistor fault on a Glow-worm Betacom boiler is around £120 to £180. This includes the cost of the replacement part and labour, as thermistor replacements are generally straightforward but require a qualified technician.