BoilerFaultCodes E615 High
Boiler Fault Code E615
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E615 appears across 1 boiler brand and 7 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's internal computer is experiencing a system error and cannot process commands correctly, meaning it will likely stop working to protect itself. (As reported on Navien NCB)
Pick your boiler brand for the E615 fix
Source
Information for the E615 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