BoilerFaultCodes E85 739 High
Boiler Fault Code E85 739
Also written as E85739 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E85 739 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is struggling to light because the part responsible for creating the spark to start the flame is failing or worn out. (As reported on Potterton Promax 15 & 24)
Pick your boiler brand for the E85 739 fix
Source
Information for the E85 739 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