What does the Baxi 600 Series E450 fault code mean?
The E450 fault code on the Baxi 600 Series indicates a problem with the domestic hot water (DHW) thermostat. This fault typically suggests that the thermostat is either malfunctioning or not communicating properly with the boiler’s control system.
Common Causes
- Faulty DHW Thermostat: The thermostat may be defective, preventing it from accurately measuring the water temperature.
- Wiring Issues: Damaged or loose wiring connections to the thermostat can disrupt communication and cause the fault code to appear.
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 expertise to ensure safety and compliance with regulations.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the E450 fault could range around £150 to £250, primarily depending on whether the thermostat needs replacement or if wiring repairs are necessary.