BoilerFaultCodesTechnical description
Debris in flue system, Debris in flue venturi. Boiler or flue system has developed a fault.
What causes this fault?
This fault occurs when the boiler's safety sensors detect that harmful exhaust gases are not being cleared from the system correctly. The most common cause is a buildup of dust or debris inside the small tubes that monitor airflow, or a mechanical failure in the fan that pushes the gases outside.
This fault often occurs during periods of high wind, which can create back-pressure in the flue and trigger the sensitive air pressure switch.
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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