BoilerFaultCodesYour boiler has detected that the internal safety fan isn't moving air properly, so it has shut down for safety.
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 internal computer sends power to the fan but does not receive a signal back confirming that air is moving through the flue. The most common reasons are a motor failure within the fan itself or a blockage in the small plastic tubes that sense air pressure. Without this confirmed airflow, the boiler cannot safely light the flame and will stay in a safe mode.
This issue can occasionally follow a period of heavy wind or storms, as strong gusts can sometimes interfere with the pressure sensors or blow debris into the external flue pipe.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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