BoilerFaultCodesYour boiler is struggling to clear exhaust fumes safely, which has caused it to shut down for protection.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Problem with fan/flue. Reset as described for code 01.
What causes this fault?
This fault occurs when the boiler's safety sensors detect that the fan isn't spinning at the right speed or the exhaust gases aren't being pushed out of the flue pipe correctly. The most common reasons are a build-up of dirt inside the fan, a blockage in the external flue pipe, or a failure in the pressure switch that monitors air flow. Because the boiler cannot guarantee that harmful fumes are being safely removed, it shuts down as a critical safety precaution.
This fault is more frequent during periods of high winds, which can create back-pressure in the flue and interfere with the air pressure sensor's readings.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 03 — no call-out fees, no surprises.
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