BoilerFaultCodesYour boiler has stopped working because it cannot confirm that the internal fan is safely clearing waste gases out of the flue.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Air flow proving fault - that is fan or air pressure switch
What causes this fault?
This fault occurs when the boiler's safety system detects that the fan isn't spinning fast enough or the air pressure is incorrect to safely push exhaust fumes outside. The most common reasons are a seized fan motor, a perished rubber tube leading to the sensor, or a blockage within the flue pipe itself.
This issue is more common during the first cold snap of autumn, as fan bearings can seize up after being idle throughout the summer months.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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