BoilerFaultCodes HHHHH:::::AAAAA High
Boiler Fault Code HHHHH:::::AAAAA
Also written as HHHHHAAAAA — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code HHHHH:::::AAAAA 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 has stopped heating your radiators and water because the internal water pressure has dropped too low. (As reported on Ideal Isar HE)
Pick your boiler brand for the HHHHH:::::AAAAA fix
Source
Information for the HHHHH:::::AAAAA 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