7.iii High

Boiler Fault Code 7.iii

Also written as 7III — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 7.iii 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 has lost the air pressure needed to run smoothly, causing it to release excess water to prevent unsafe pressure levels within the system. (As reported on Chaffoteaux Sterling FF)

Pick your boiler brand for the 7.iii fix

Source

Information for the 7.iii 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