What does the Ideal Mexico HE F65 fault code mean?
The F65 fault code on the Ideal Mexico HE indicates a fault with the domestic hot water (DHW) thermistor. This component is responsible for measuring the temperature of the water, and a fault can lead to issues with hot water supply.
Common Causes
- Faulty DHW Thermistor: The thermistor may be malfunctioning or damaged, leading to incorrect temperature readings.
- Wiring Issues: Damaged or loose wiring connections to the thermistor can cause communication failures between the thermistor and the boiler control board.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as working with gas appliances can be dangerous. Attempting to fix electrical components without proper training can lead to further damage or safety hazards.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the DHW thermistor on an Ideal Mexico HE is approximately £120. This includes the cost of the part and labour, as the thermistor itself is relatively inexpensive but requires professional installation.