BoilerFaultCodesTechnical description
Burner does not start. Air pressure switch does not close.
What causes this fault?
This fault occurs when the boiler's internal safety checks fail to detect the necessary airflow required to start the combustion process. The most common reason is that the fan is either not spinning fast enough or a small rubber tube inside the unit has become blocked or perished, preventing the sensor from 'proving' it is safe to light the burner.
This fault can be more common during periods of high winds, as strong gusts can occasionally create back-pressure in the flue that prevents the air pressure switch from closing correctly.
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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