What does the Ideal Mini F42 fault code mean?
The F42 fault code on the Ideal Mini indicates a domestic hot water (DHW) temperature fault, which suggests that the boiler is unable to heat the water to the required temperature. This can lead to insufficient hot water supply for taps and showers.
Common Causes
- Faulty DHW Sensor: The temperature sensor may be malfunctioning, causing incorrect readings and preventing the boiler from heating water properly.
- Blocked Heat Exchanger: A blockage in the heat exchanger can restrict water flow, leading to inadequate heating and triggering the fault code.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer for this issue, as it involves gas and electrical components that require professional handling. Attempting DIY repairs could pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F42 fault could be around £150 to £250, primarily depending on whether the DHW sensor needs replacement or if the heat exchanger requires cleaning or repair.