What does the Baxi Duo-tec F35 fault code mean?
The F35 fault code on a Baxi Duo-tec boiler indicates a fault with the printed circuit board (PCB). This issue can prevent the boiler from operating correctly, leading to heating and hot water failures.
Common Causes
- Electrical Faults: Issues such as short circuits or damaged wiring can affect the PCB’s functionality.
- Component Failure: Components on the PCB may fail due to age or manufacturing defects, leading to the F35 error.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer to diagnose and repair the PCB fault, as working with gas and electrical components can be dangerous and requires professional expertise.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for a PCB replacement on a Baxi Duo-tec boiler is around £300 to £400. This includes the cost of the part and labour, reflecting the complexity of the repair and the need for a qualified technician.