BoilerFaultCodes.com
5.2 High Lockout

Your boiler is struggling to light the gas safely, which means your heating and hot water have stopped working.

Call an engineer soon

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

Technical description: Automatic gas igniter status and/or fault

What causes this fault?

This fault occurs when the boiler's control system attempts to light the gas but fails to detect a successful flame. The most common reasons are worn-out ignition sparks that can no longer bridge the gap to start a fire, or a faulty sensor that cannot confirm the boiler is safely lit.

Typical repair cost £120-280 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

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Protect yourself from future repair bills

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