BoilerFaultCodesMain 3 red flashes Fault Code
Also written as 3REDFLASHES — same fault.
The Main 3 red flashes fault code means: your boiler has failed to light several times and has now locked itself out for safety.. It appears on 1 Main model in our database.
Technical description: Ignition fault. Boiler has attempted to light 5 times and failed.
DIY fix possible
Check that your gas supply is turned on at the meterCheck if other gas appliances in your home are workingPress and hold the selector switch in the 'reset' position for 5 seconds
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A cover plan would handle faults like 3 red flashes: no call-out fees, no surprise bills.
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Main models that show the 3 red flashes fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Main 3 red flashes fault code information on this page is sourced and cross-checked against the official Main service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026