93 Low

Boiler Fault Code 93

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 93 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’s solar heating connection has a faulty sensor that is incorrectly detecting a short circuit, preventing your solar panels from helping to heat your water. (As reported on Viessmann Vitodens 333)

Pick your boiler brand for the 93 fix

Alpha 93 10 models Viessmann 93 7 models Vokera 93 3 models

Source

Information for the 93 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