Low
Vitotronic 300 on Viessmann A8

Your boiler has switched to a protective mode because the outdoor temperature has dropped to freezing, causing it to run the heating pump continuously to prevent pipes from freezing.

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.

Technical description

Activates after 0°C / 32°F outdoor temperature

DIY fix possible

Check that your outdoor sensor is not covered by snow or debrisEnsure your thermostat is set to your desired room temperatureWait for the outdoor temperature to rise above freezing for the notification to clear automatically

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