Flashing on and off Low
Your boiler is temporarily pausing to melt away ice build-up and protect the external components during very cold weather.
Technical description: Defrosting
Typical repair cost: £0 (including labour)
DIY fix possible
Wait for the defrost cycle to finish automatically (usually 10-15 minutes)Check that the external condensate pipe is not frozen or blocked with iceEnsure there is no snow or debris obstructing the boiler's external flue
Protect yourself from future repair bills
A boiler cover plan would cover faults like Flashing on and off — no call-out fees, no surprises.
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