What does the Ideal Logic Max F40 fault code mean?
The F40 fault code on the Ideal Logic Max indicates a problem with the domestic hot water (DHW) temperature sensor. This fault typically arises when the sensor is malfunctioning or the temperature readings are outside the expected range.
Common Causes
- Faulty DHW Temperature Sensor: The sensor may be defective, leading to incorrect temperature readings.
- Wiring Issues: Damaged or loose wiring connections can disrupt the signal between the sensor and the boiler’s control board.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and repair this fault, as it involves gas and electrical components that require professional expertise.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for the F40 fault could be around £150 to £250, primarily due to the potential need for a new temperature sensor and associated labour costs.