BoilerFaultCodes 31.05 Low
Boiler Fault Code 31.05
Also written as 3105 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 31.05 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is operating normally and this code is simply an information message confirming that it is running at its maximum designed heat output for high-efficiency condensing mode. (As reported on Baxi Barcelona)
Pick your boiler brand for the 31.05 fix
Source
Information for the 31.05 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