What does the Glow-worm Energy F46 fault code mean?
The F46 fault code indicates a domestic hot water (DHW) overheat condition in the Glow-worm Energy boiler. This safety feature activates when the temperature of the water exceeds safe limits, preventing potential damage or hazards.
Common Causes
- Faulty Thermistor: A malfunctioning thermistor may incorrectly read the temperature, causing the boiler to shut down due to perceived overheating.
- Blocked Heat Exchanger: A blockage in the heat exchanger can restrict water flow, leading to overheating and triggering the fault code.
Can I fix it myself? (DIY)
It is strongly advised to call a Gas Safe Engineer to diagnose and repair the issue, as working on gas appliances can be dangerous. Attempting DIY repairs could lead to further complications or safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F46 fault could range around £150 to £250, primarily depending on whether the thermistor needs replacement or if the heat exchanger requires cleaning or servicing.