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 sensors cannot detect a steady flow of air through the unit. While the fan might be spinning, a blockage in the plastic tubes, a build-up of dirt, or a failing motor prevents the system from proving it is safe to ignite. Because the boiler cannot guarantee that harmful exhaust fumes are being pushed outside, it shuts down as a safety precaution.
This issue often surfaces during the first cold spell of autumn when a fan that has been idle over summer struggles to spin up to the required speed.
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.
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