Low
I.56 on Viessmann Vitodens 200-W B2KF Combi

Your boiler is receiving a signal from an external control or thermostat to provide heat, so it is operating normally rather than experiencing a breakdown.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

External demand active

From this model's manual
Verified against the Viessmann Vitodens 200 W B2kf Combi 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.

DIY fix possible

Check your external room thermostat or smart hub to see if a schedule or 'boost' is active.Verify if your hot water pre-heat function is currently running.Adjust your thermostat temperature down to see if the status message clears.

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Related fault codes

I.51View →I.52View →

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