BoilerFaultCodes Vitotronic 300 Low
Boiler Fault Code Vitotronic 300
Also written as VITOTRONIC300 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Vitotronic 300 appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning 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. (As reported on Viessmann A8)
Pick your boiler brand for the Vitotronic 300 fix
Source
Information for the Vitotronic 300 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026