BoilerFaultCodes 1-E3 High
Boiler Fault Code 1-E3
Also written as 1E3 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 1-E3 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's internal electronic computer chip is either missing, loose, or incompatible with the unit's software. (As reported on Worcester Bosch Greenstar 8000 Life/Style)
Pick your boiler brand for the 1-E3 fix
Source
Information for the 1-E3 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