BoilerFaultCodesTechnical description
Air intake/flue blocked
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that the fan is not moving air through the system at the required speed. The most common reasons are a physical blockage in the flue pipe outside, a build-up of debris within the fan itself, or a failure in the electronic sensor that monitors air pressure.
This issue is more frequent during periods of high winds or extreme cold, as gales can disrupt the airflow through the flue and heavy snow can physically block the air intake.
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.
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