Technical description
Flame Sensor + Harness Buccleuch, Ref. BE/3461/SI
What causes this fault?
This fault occurs when the boiler's control board cannot confirm that a flame has successfully lit after an ignition attempt. The most common reasons are a worn-out sensor that can no longer 'see' the flame, a faulty ignition lead, or a loose connection in the internal wiring harness. Because the boiler cannot verify it is burning gas safely, it shuts down as a protective measure.
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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