What the manual says
Manufacturer manualBoiler reset in progress
Shared across the 400 424 / 428 Combi range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
DIY fix possible
Wait for 5 to 10 minutes to allow the boiler to complete its internal self-check.Do not turn the power off while this message is displayed.If the code persists for more than 15 minutes, turn the boiler off at the mains switch, wait 30 seconds, and turn it back on.
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Related fault codes
All 41 fault codes on the 400 424 / 428 Combi
Seeing a different code? Every code this model can display, in one place.