1-A7 Medium

Boiler Fault Code 1-A7

Also written as 1A7 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 1-A7 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 has detected an issue with a temperature sensor normally used in more complex heating systems, often meaning a sensor is faulty or incorrectly configured. (As reported on Worcester Bosch Greenstar 8000 Life/Style)

Pick your boiler brand for the 1-A7 fix

Source

Information for the 1-A7 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