Vaillant Burner lockout indicator (red) Fault Code
Also written as BURNERLOCKOUTINDICATORRED — same fault.
The Vaillant Burner lockout indicator (red) fault code means: 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.. It appears on 1 Vaillant model in our database.
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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Vaillant models that show the Burner lockout indicator (red) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vaillant Burner lockout indicator (red) fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026