How much does it cost to fix boiler error code E787?

Typical repair cost for the boiler E787 fault is £120-250 including labour.

E787 High

Boiler Fault Code E787

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code E787 appears across 1 boiler brand and 8 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 system has encountered a temporary processing glitch and has locked itself out to prevent any potential issues. (As reported on Navien LCB700)

Pick your boiler brand for the E787 fix

Navien E787 8 models

Source

Information for the E787 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