What does the Ideal Logic Max F77 fault code mean?
The F77 fault code indicates a calibration mismatch with the domestic hot water (DHW) flow switch in the Ideal Logic Max boiler. This issue prevents the boiler from accurately detecting water flow, which can disrupt hot water supply.
Common Causes
- Faulty Flow Switch: The flow switch may be malfunctioning or damaged, leading to incorrect readings.
- Wiring Issues: Damaged or loose wiring connections to the flow switch can cause communication problems with the boiler’s control system.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves gas and electrical components that require professional handling. Attempting DIY repairs could be dangerous.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F77 fault code is around £150 to £250, primarily due to the need for a new flow switch and potential labour costs for a qualified engineer.