High Lockout
E01612 on Worcester Bosch 24/28CDi II RSF

Your boiler has failed to detect a flame and has safely shut down to prevent unburned gas from building up.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

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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