What does the Glow-worm Ultimate F22 fault code mean?
The F22 fault code on the Glow-worm Ultimate indicates a dry fire condition or low water pressure within the system. This typically means that the boiler is unable to detect sufficient water flow, which can lead to overheating and potential damage.
Common Causes
- Low Water Pressure: This can occur due to leaks in the system or insufficient water supply, preventing the boiler from operating correctly.
- Air in the System: Trapped air can cause blockages, leading to inadequate water flow and triggering the F22 fault code.
Can I fix it myself? (DIY)
If you are comfortable, you can check the pressure gauge on your boiler. If it reads below 1 bar, you can safely re-pressurise the system by using the filling loop. However, if you suspect gas or electrical issues, it is crucial to call a Gas Safe Engineer.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F22 fault could range around £150 to £250, primarily for re-pressurising the system or fixing leaks. This cost reflects the typical service charge for a qualified engineer to diagnose and resolve the issue.