What does the Baxi 600 Series E620 fault code mean?
The E620 fault code on the Baxi 600 Series indicates a problem with the domestic hot water (DHW) thermostat. This fault typically means that the thermostat is either malfunctioning or not detecting the correct temperature, affecting the boiler’s ability to heat water properly.
Common Causes
- Faulty DHW Thermostat: The thermostat may be defective or damaged, preventing it from accurately reading the water temperature.
- Wiring Issues: Damaged or loose wiring connections to the thermostat can disrupt communication between the thermostat and the boiler.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and repair the issue, as working with gas appliances can be dangerous. Attempting to fix electrical components without proper training can also pose safety risks.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for the E620 fault code is around £150 to £250, which includes the replacement of the DHW thermostat and any necessary labour. This cost reflects the price of the part and the expertise required for safe installation.