BoilerFaultCodes SOOT FORMED Emergency
Boiler Fault Code SOOT FORMED
Also written as SOOTFORMED — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code SOOT FORMED 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 is struggling to breathe, causing a build-up of waste material that indicates it is not burning gas cleanly, which can be dangerous. (As reported on Chaffoteaux Britony II 30FF)
Pick your boiler brand for the SOOT FORMED fix
Source
Information for the SOOT FORMED 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