High
Burner lockout indicator (red) on Vaillant Turbomax VUW 242/1

Your boiler has stopped working because it failed to ignite, which could be due to a gas supply issue, a lack of water pressure, or an internal mechanical fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Illuminates if the burner fails to light within 10 seconds of the ignition indicator. This light will also illuminate if the burner has been prevented from lighting due to lack of water or poor water circulation.

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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