7-3 High

Boiler Fault Code 7-3

Also written as 73 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 7-3 appears across 2 boiler brands 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 has detected a communication problem with one of its internal temperature sensors, causing it to stop operating as a safety precaution. (As reported on Ideal Logic Air)

Pick your boiler brand for the 7-3 fix

Baxi 7-3 1 model Ideal 7-3 1 model

Source

Information for the 7-3 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