BoilerFaultCodes E515 High
Boiler Fault Code E515
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E515 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 has detected an internal communication error with its electronic brain, meaning it has safely shut itself down to prevent unreliable operation. (As reported on Navien LCB700)
Pick your boiler brand for the E515 fix
Source
Information for the E515 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