High
All Boilers on Viessmann Vitola Biferral

Your boiler's main control system has lost its programmed settings or is struggling to communicate with the internal sensors, meaning it cannot decide when to turn on or off.

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

Control mode issue

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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