What does the Baxi Platinum F79 fault code mean?
The F79 fault code on a Baxi Platinum boiler indicates that the central heating (CH) return temperature is excessively high, which can prevent the boiler from operating efficiently. This issue may lead to overheating and potential damage if not addressed promptly.
Common Causes
- Blocked Heat Exchanger: A blockage in the heat exchanger can restrict water flow, causing the return temperature to rise excessively.
- Faulty Thermistor: A malfunctioning thermistor may incorrectly read the temperature, leading to erroneous high return temperature readings.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and resolve this issue, as it may involve gas or electrical components that require professional expertise. Attempting DIY repairs could pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F79 fault could range from £150 to £300, depending on whether a thermistor replacement or heat exchanger cleaning is required. This estimate includes parts and labour costs typical for such repairs.