What does the Glow-worm Energy F33 fault code mean?
The F33 fault code on the Glow-worm Energy boiler indicates a high temperature fault, which typically means that the boiler is overheating. This can lead to safety mechanisms activating to prevent damage or hazards.
Common Causes
- Blocked Heat Exchanger: A build-up of debris or limescale can restrict water flow, causing the boiler to overheat.
- Faulty Temperature Sensor: If the temperature sensor is malfunctioning, it may incorrectly read high temperatures, triggering the fault code.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves potential gas and electrical components that require professional handling. Attempting DIY repairs could pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F33 fault could range from £150 to £300, depending on whether the issue is a blocked heat exchanger or a faulty temperature sensor. This includes parts and labour costs for a qualified engineer.