Baxi Megaflo System 24 HE Fault codes & diagnostics

9 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

System Natural Gas 24 kW 2007-2012 Discontinued

Replaced by: Megaflo System Compact GA

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Severity at a glance

Each cell = one fault code. Hover to identify.

8 High 1 Medium

Fault codes

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Ensure all radiator valves are open to allow water to flow
Wait for the boiler to cool down completely
Turn the selector switch to the reset position for five seconds and then release

Locate the external filling loop on the pipework beneath the boiler.
Slowly open the tap or taps on the filling loop until you hear water entering the system.
Monitor the pressure gauge and close the taps once the needle reaches between 1.0 and 1.5 bar.

Check that your gas supply is turned on and that other gas appliances (like a hob) are working.
If it is freezing outside, check if the plastic condensate drain pipe leading outdoors has frozen and thaws it with warm water.
Press the 'Reset' button for five seconds to see if the boiler restarts.