High
lock out on Vaillant Turbomax VUW 242/1

Your boiler has stopped working because it cannot detect a flame, most likely because the gas supply is interrupted or there is air trapped in the pipes.

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.

What the manual says

Manufacturer manual

The 'lock out' indicator will illuminate. This usually means that the gas supply is turned off, or is not purged of air.

From this model's manual
Verified against the Vaillant Turbomax Vuw 242 1 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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