What does the Glow-worm Ultimate F25 fault code mean?
The F25 fault code on the Glow-worm Ultimate indicates an ignition failure, meaning the boiler is unable to ignite the gas to start the heating process. This can lead to the boiler shutting down to prevent unsafe conditions.
Common Causes
- Faulty Ignition Electrode: The ignition electrode may be damaged or dirty, preventing it from creating a spark to ignite the gas.
- Gas Supply Issue: There may be a blockage or interruption in the gas supply, which can prevent the boiler from receiving the necessary fuel to ignite.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any gas or electrical issues. However, if you suspect a pressure issue, you can check the pressure gauge and reset the boiler if necessary, following the manufacturer’s instructions.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving an F25 fault could range from £100 to £250, depending on whether the ignition electrode needs replacing or if there are gas supply issues that require more extensive work.