BoilerFaultCodes 703 High
Boiler Fault Code 703
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 703 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 has detected a communication problem between its main control board and the display panel, meaning the internal components cannot talk to each other properly. (As reported on Ariston Alteas One)
Pick your boiler brand for the 703 fix
Source
Information for the 703 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