High
Vitocrossal 200 on Viessmann Vitorond 100

Your boiler has detected a critical internal error or a mismatch with its electronic settings, causing it to shut down completely for safety.

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

Case A: Burner control unit in a fault state; system cools down; burner control unit locked out.Case B: Type of coding card

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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