BoilerFaultCodes 2a High
Boiler Fault Code 2a
Also written as 2A — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 2a 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 is making loud noises because the water pressure inside your heating system has dropped too low to operate correctly. (As reported on Chaffoteaux Celtic 2 24 Rsc)
Pick your boiler brand for the 2a fix
Source
Information for the 2a 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