How much does it cost to fix boiler error code E593?

Typical repair cost for the boiler E593 fault is £150-300 including labour.

E593 High

Boiler Fault Code E593

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code E593 appears across 1 boiler brand and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's electronic control panel is experiencing a communication fault, which prevents the display from responding or controlling the unit properly. (As reported on Navien NCB 28 HE)

Pick your boiler brand for the E593 fix

Navien E593 6 models

Source

Information for the E593 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