BoilerFaultCodes ALARM 02 High
Boiler Fault Code ALARM 02
Also written as ALARM02 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code ALARM 02 appears across 1 boiler brand and 2 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 that the water pressure is too low, which prevents it from heating up or providing hot water. (As reported on Sime iQE Comfort 30)
Pick your boiler brand for the ALARM 02 fix
Source
Information for the ALARM 02 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 7 July 2026