What does the Baxi Megaflo E850 fault code mean?
The E850 fault code on a Baxi Megaflo indicates a reliability issue within the domestic hot water (DHW) system. This fault suggests that the boiler is unable to maintain consistent performance for hot water delivery.
Common Causes
- Faulty DHW Sensor: A malfunctioning sensor can lead to incorrect temperature readings, causing the system to fail.
- Blocked Heat Exchanger: A blockage can restrict water flow, impacting the efficiency of the DHW system.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for any issues related to gas or electrical components. Attempting to fix these without proper qualifications can be dangerous.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for the E850 fault could range around £150 to £300, primarily depending on whether the DHW sensor needs replacement or if the heat exchanger requires cleaning or replacement.