n8 High

Boiler Fault Code n8

Also written as N8 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code n8 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 The boiler's temperature sensors have detected an issue with the water flow or heat exchange, causing the system to stop working to prevent internal damage. (As reported on Protherm 100EC)

Pick your boiler brand for the n8 fix

Glow-worm n8 1 model Protherm n8 1 model

Source

Information for the n8 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