BoilerFaultCodesTechnical description
Check fan rotates. Replace if necessary. Check pressure switch. Replace if necessary. Replace detection probe.
What causes this fault?
This fault occurs when the boiler's safety system cannot confirm that the fan is successfully clearing combustion gases from the unit. The most common reasons include a mechanical failure of the fan motor, a blockage in the flue pipe, or a faulty sensor that is incorrectly reporting a lack of airflow. Without this constant flow of fresh air, the boiler shuts down to prevent dangerous fumes from building up.
This issue can occur more frequently during periods of high winds, which can create back-pressure in the flue and interfere with the air pressure switch readings.
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.