BoilerFaultCodes 9 E 30 Medium
Boiler Fault Code 9 E 30
Also written as 9E30 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 9 E 30 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 has temporarily paused because it has detected a large temperature difference between the water leaving the boiler and the water returning to it, suggesting a blockage or poor circulation. (As reported on Saunier Duval Ecosy)
Pick your boiler brand for the 9 E 30 fix
Source
Information for the 9 E 30 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