What does the Glow-worm Ultimate F24 fault code mean?
The F24 fault code on the Glow-worm Ultimate indicates an overheat condition within the boiler. This typically occurs when the temperature of the water in the system exceeds safe operating limits, triggering a safety mechanism to prevent damage.
Common Causes
- Blocked Heat Exchanger: A build-up of debris or limescale can restrict water flow, causing overheating.
- Faulty Thermostat: If the thermostat is malfunctioning, it may not accurately regulate the water temperature, leading to overheating.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer to diagnose and repair the issue, as working with gas appliances can be dangerous. However, you can check the pressure gauge and reset the boiler if it is low or has tripped.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F24 fault could range from £150 to £300, depending on whether the heat exchanger needs cleaning or replacement, or if the thermostat requires servicing.