What does the Baxi Megaflo E520 fault code mean?
The E520 fault code on a Baxi Megaflo indicates a central heating (CH) system pressure fault, typically meaning that the system pressure is too low or too high. This can lead to inadequate heating performance and may require immediate attention to ensure safe operation.
Common Causes
- Low System Pressure: This can occur due to leaks in the heating system, air trapped in the system, or insufficient water in the boiler.
- High System Pressure: This may be caused by a faulty pressure relief valve or expansion vessel, leading to excessive pressure buildup.
Can I fix it myself? (DIY)
If you are comfortable, you can check the pressure gauge on the boiler and attempt to refill the system using the filling loop if the pressure is low (typically below 1 bar). However, if you suspect a leak or if the pressure is too high, it is essential to call a Gas Safe Engineer for safety reasons.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the E520 fault could range from £150 to £300, depending on whether the issue is a simple pressure adjustment or if it requires replacing components like the pressure relief valve or expansion vessel.