93 Low

Boiler Fault Code 93

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 93 appears across 6 boiler brands and 12 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-F)

Pick your boiler brand for the 93 fix

Alpha 93 4 models Evo 93 1 model Ideal 93 1 model Keston 93 1 model Viessmann 93 4 models Vokera 93 1 model

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 31 August 2026