BoilerFaultCodes A98 High
Boiler Fault Code A98
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code A98 appears across 1 boiler brand and 6 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 computer is experiencing a communication error, meaning it has lost its ability to regulate itself safely and has shut down to prevent damage. (As reported on Ariston Clas One)
Pick your boiler brand for the A98 fix
Source
Information for the A98 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