BoilerFaultCodes b43 High
Boiler Fault Code b43
Also written as B43 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code b43 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 The internal computer settings for your boiler have been altered, causing the system to stop working because it no longer knows how to run safely. (As reported on Remeha Quinta 30)
Pick your boiler brand for the b43 fix
Source
Information for the b43 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