How much does it cost to fix boiler error code E278?

Typical repair cost for the boiler E278 fault is £150-250 including labour.

E278 High

Boiler Fault Code E278

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code E278 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 accurately read the temperature of the water being sent to your radiators, causing it to stop working for your own protection. (As reported on Navien NCM 1130HH)

Pick your boiler brand for the E278 fix

Navien E278 3 models

Source

Information for the E278 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