High Lockout
S.03 on Glow-worm Flexicom hx

Your boiler is failing to light the gas flame properly during its first stage of operation.

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

ignition

What causes this fault?

This fault occurs when the boiler's control board sends a signal to start the fire, but it fails to detect a stable flame during the initial ignition sequence. The most common reasons are a worn-out spark electrode that can no longer create a spark, or a debris-clogged ignition lead preventing the electrical current from reaching the burner.

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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