BoilerFaultCodes 70/90 Medium
Boiler Fault Code 70/90
Also written as 7090 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 70/90 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 displaying its power output identification code rather than an error, which usually means the system's electronic brain is failing to read the boiler's settings correctly. (As reported on Grant Euroflame Condensing)
Pick your boiler brand for the 70/90 fix
Source
Information for the 70/90 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