How much does it cost to fix boiler error code E596?

Typical repair cost for the boiler E596 fault is £90-180 including labour.

E596 Medium

Boiler Fault Code E596

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code E596 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 has lost its digital connection to your room thermostat, meaning it cannot receive signals to turn the heating on or off. (As reported on Navien NCB 28 HE)

Pick your boiler brand for the E596 fix

Navien E596 6 models

Source

Information for the E596 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