Limescale Build-up Medium
Boiler Fault Code Limescale Build-up
Also written as LIMESCALEBUILDUP — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Limescale Build-up 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 has detected that limescale is building up inside the part that heats your tap water, so it is limiting its own temperature to protect itself from further damage. (As reported on Ariston E-Combi One 30)
Pick your boiler brand for the Limescale Build-up fix
Source
Information for the Limescale Build-up 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