BoilerFaultCodes JP4 Emergency
Boiler Fault Code JP4
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code JP4 appears across 1 boiler brand and 2 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 an incorrect setting regarding the type of fuel it is using, such as a mismatch between mains gas and bottled gas. (As reported on Sime Format B Combi)
Pick your boiler brand for the JP4 fix
Source
Information for the JP4 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 7 July 2026