BoilerFaultCodesTechnical description
Fan or flue pressure switch failure
What causes this fault?
This fault occurs when the boiler's safety sensors detect that the fan isn't moving enough air to safely vent exhaust gases out of the building. The most common reason is a mechanical failure of the fan motor or a blockage in the small plastic tubes that monitor air pressure. Without a clear path for waste gases to escape, the boiler automatically shuts down to prevent dangerous fumes from entering your home.
This issue can be more frequent during very windy weather, as strong gusts can sometimes create back-pressure in the flue that interferes with the 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.