High
1A, 1B on Viessmann Vitorond 100

Your boiler's burner has stopped working and is locked out, meaning the system cannot fire up to provide heating or hot water.

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

Burner blocked

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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