BoilerFaultCodes 323 / A8 High
Boiler Fault Code 323 / A8
Also written as 323A8 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 323 / A8 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 control computer has lost its connection, preventing it from processing commands and operating your heating or hot water correctly. (As reported on Worcester Bosch Greenstar CDi Compact)
Pick your boiler brand for the 323 / A8 fix
Source
Information for the 323 / A8 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