BoilerFaultCodes 93 H.....4.... High
Boiler Fault Code 93 H.....4....
Also written as 93H4 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 93 H.....4.... appears across 1 boiler brand and 3 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 that it is firing without enough water inside, which has caused the temperature sensors to overheat or report a fault. (As reported on Ideal Esprit HE)
Pick your boiler brand for the 93 H.....4.... fix
Source
Information for the 93 H.....4.... 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