What does the Baxi Platinum F42 fault code mean?
The F42 fault code on a Baxi Platinum boiler indicates a problem with the domestic hot water (DHW) temperature, suggesting that the boiler is unable to heat the water to the required temperature. This could lead to insufficient hot water supply for taps and showers.
Common Causes
- Faulty DHW Sensor: The sensor may be malfunctioning, causing incorrect temperature readings and triggering the fault code.
- Blocked Heat Exchanger: A blockage in the heat exchanger can prevent proper heat transfer, resulting in inadequate hot water heating.
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 for safety reasons.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F42 fault could be around £150 to £250, primarily due to the potential need for a new DHW sensor or cleaning the heat exchanger, which involves labour and parts.