What does the Glow-worm Energy F66 fault code mean?
The F66 fault code indicates a problem with the central heating (CH) pressure switch, which is responsible for monitoring the pressure within the system. This fault typically suggests that the pressure is either too low or the switch itself is malfunctioning.
Common Causes
- Low Water Pressure: Insufficient water pressure in the heating system can trigger the F66 fault code, often due to leaks or insufficient filling.
- Faulty Pressure Switch: A malfunctioning pressure switch may fail to detect the correct pressure levels, leading to the fault code being displayed.
Can I fix it myself? (DIY)
If you are comfortable with basic plumbing tasks, you can check the pressure gauge on your boiler and top up the system if the pressure is low. However, if the pressure is adequate and the fault persists, it is essential to call a Gas Safe Engineer to diagnose and repair any gas or electrical issues safely.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving an F66 fault code is around £150 to £250. This includes the potential replacement of the pressure switch and any necessary labour costs, reflecting the complexity of the issue and the need for a qualified technician.