What does the Baxi Duo-tec F75 fault code mean?
The F75 fault code on a Baxi Duo-tec boiler indicates a fault with the domestic hot water (DHW) thermostat. This typically means that the thermostat is either malfunctioning or not detecting the correct temperature, leading to issues with hot water supply.
Common Causes
- Faulty DHW Thermostat: The thermostat may be defective or damaged, preventing it from accurately measuring the water temperature.
- Wiring Issues: Damaged or loose wiring connections to the thermostat can disrupt communication between the thermostat and the boiler.
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. Attempting to fix it yourself could pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for the F75 fault could range from £150 to £250, depending on whether the thermostat needs replacing or if wiring repairs are necessary. This cost reflects the price of parts and labour for a qualified engineer.