What does the Baxi Duo-tec F81 fault code mean?
The F81 fault code on a Baxi Duo-tec boiler indicates a fault with the domestic hot water (DHW) display. This typically suggests an issue with the boiler’s ability to accurately read or display the temperature of the hot water.
Common Causes
- Faulty DHW Sensor: The sensor may be malfunctioning, leading to incorrect temperature readings.
- Wiring Issues: Damaged or loose wiring connections can disrupt communication between the sensor and the control board.
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 DIY repairs could be dangerous.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the F81 fault could be around £150 to £250, primarily depending on whether the DHW sensor needs replacing or if wiring repairs are necessary.