n6 High

Boiler Fault Code n6

Also written as N6 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code n6 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 that the water flow inside the system is restricted or blocked, preventing it from heating your home properly. (As reported on Protherm 100EC)

Pick your boiler brand for the n6 fix

Glow-worm n6 1 model Protherm n6 1 model

Source

Information for the n6 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