What does the Baxi Duo-tec F85 fault code mean?
The F85 fault code on a Baxi Duo-tec boiler indicates a domestic hot water (DHW) installation fault, which typically suggests an issue with the hot water system or its components. This can prevent the boiler from supplying hot water effectively.
Common Causes
- Incorrect Installation: The boiler may not have been installed according to the manufacturer’s specifications, leading to operational issues.
- Faulty Components: Components such as the DHW sensor or diverter valve may be malfunctioning, affecting the hot water supply.
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 expertise to ensure safety and compliance with regulations.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving an F85 fault could range from £150 to £300, depending on whether parts need replacing, such as a diverter valve or sensor, which can be costly.