How much does it cost to fix boiler error code E736?

Typical repair cost for the boiler E736 fault is £120-250 including labour.

E736 Medium

Boiler Fault Code E736

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code E736 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is struggling to talk to other units in your heating system, likely due to a loose wire or a connection issue between them. (As reported on Navien NCM 1130HH)

Pick your boiler brand for the E736 fix

Navien E736 3 models

Source

Information for the E736 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