What does the Baxi Duo-tec F43 fault code mean?
The F43 fault code on a Baxi Duo-tec boiler indicates a malfunction with the domestic hot water (DHW) temperature sensor. This issue can prevent the boiler from accurately regulating the temperature of the hot water supply.
Common Causes
- Faulty Temperature Sensor: The sensor may be defective or damaged, leading to incorrect temperature readings.
- Wiring Issues: Damaged or loose wiring connections to the temperature sensor can disrupt its functionality.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves electrical components and gas safety regulations. Attempting to fix it yourself could pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the DHW temperature sensor is around £150 to £200. This includes the cost of the part and labour, as it typically requires professional installation.