94 Medium

Boiler Fault Code 94

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 94 appears across 3 boiler brands and 20 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected a problem with the sensor that measures the water temperature in your solar cylinder, which may affect how your hot water is heated. (As reported on Viessmann Vitodens 333)

Pick your boiler brand for the 94 fix

Alpha 94 10 models Viessmann 94 7 models Vokera 94 3 models

Source

Information for the 94 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