BoilerFaultCodesTechnical description
Flue pressure switch failure
What causes this fault?
This fault occurs when the boiler's safety sensors detect that exhaust fumes are not being cleared safely through the outdoor flue pipe. It is typically caused by a blockage in the air pressure tubes, a build-up of debris in the fan, or a mechanical failure in the switch that monitors airflow.
This issue is more frequent during periods of high winds or extreme cold, which can cause pressure fluctuations or ice blockages in the external flue terminal.
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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