How to fix Baxi Duo-tec fault code F76

What does the Baxi Duo-tec F76 fault code mean?

The F76 fault code on a Baxi Duo-tec boiler indicates a problem with the central heating thermostat. This typically means that the thermostat is either faulty or not communicating properly with the boiler.

Common Causes

  • Faulty Thermostat: The thermostat may be malfunctioning or damaged, preventing it from accurately reading the temperature.
  • Wiring Issues: Loose or damaged wiring connections between the thermostat and the boiler can disrupt communication and lead to this fault code.

Can I fix it myself? (DIY)

While you can check the thermostat settings and ensure it is properly set, any repairs involving gas or electrical components should be handled by a qualified Gas Safe Engineer to ensure safety and compliance with regulations.

Estimated Repair Cost (2026 UK Prices)

The estimated repair cost for resolving the F76 fault code is around £150 to £250. This includes the cost of a replacement thermostat and labour charges, which are necessary to ensure proper installation and safety.