High Lockout
S.23 on Glow-worm Ultracom hxi

Your boiler is currently struggling to light the flame it needs to provide heating and hot water.

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 attempts to start up but fails to establish or detect a flame. The most common reasons include a worn-out ignition probe that can no longer create a spark, or a gas valve that isn't opening correctly to let fuel into the burner.

This issue can be more frequent during the first cold snap of autumn when internal components that have been idle all summer are suddenly forced to work under high demand.

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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