High Lockout
10 on Vokera Unica 24HE

Your boiler has failed to ignite, which means it cannot provide heat or hot water because it isn't successfully lighting a flame.

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

Check gas supply, check flue system, check polarity

What causes this fault?

This fault occurs when the boiler's control system attempts to start a flame but fails to detect one after several attempts. The most common reasons include a lack of gas reaching the unit, a worn-out ignition spark, or a blockage in the pipes that carry exhaust fumes away from your home.

This issue is more frequent during extremely cold spells, as external gas meters or regulator components can sometimes struggle with freezing temperatures or 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.

Find a Gas Safe engineer
Search the official register →

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