What does the Baxi 600 Series E670 fault code mean?
The E670 fault code indicates a lockout condition in the domestic hot water (DHW) system of the Baxi 600 Series boiler. This typically occurs when the boiler fails to detect a flow of hot water, preventing it from operating correctly.
Common Causes
- Blocked DHW Flow Sensor: A blockage in the flow sensor can prevent the boiler from detecting water flow, leading to a lockout.
- Faulty DHW Thermistor: If the thermistor is malfunctioning, it may incorrectly signal the boiler, causing it to enter a lockout state.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any issues related to gas or electrical components. However, you can check the pressure gauge and ensure it is within the normal range (1-1.5 bar) and reset the boiler by pressing the reset button if applicable.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the E670 fault could range from £150 to £250, depending on whether the issue is a simple sensor cleaning or replacement. A new flow sensor typically costs around £100, plus labour charges.