What does the Baxi Duo-tec F71 fault code mean?
The F71 fault code on a Baxi Duo-tec boiler indicates a fault within the domestic hot water (DHW) circuit. This typically means there is an issue preventing the boiler from effectively heating water for taps and showers.
Common Causes
- Blocked DHW Heat Exchanger: A build-up of limescale or debris can restrict water flow and heat transfer.
- Faulty DHW Sensor: If the temperature sensor is malfunctioning, it may not accurately detect water temperature, leading to operational issues.
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 resolving an F71 fault could range from £150 to £300, depending on whether the issue is a simple sensor replacement or a more complex heat exchanger cleaning or replacement.