BoilerFaultCodesWhat the manual says
Manufacturer manualAir 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 is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like Neon 3 NOT lit: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.