How much does it cost to fix boiler error code HIGH SMOKE NUMBER?

Typical repair cost for the boiler HIGH SMOKE NUMBER fault is £150-300 including labour.

HIGH SMOKE NUMBER Emergency

Boiler Fault Code HIGH SMOKE NUMBER

Also written as HIGHSMOKENUMBER — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code HIGH SMOKE NUMBER appears across 1 boiler brand and 7 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is burning fuel improperly, which indicates the system is producing harmful exhaust fumes and needs an urgent inspection to prevent carbon monoxide buildup. (As reported on Worcester Bosch Greenstar Camray Utility)

Pick your boiler brand for the HIGH SMOKE NUMBER fix

Worcester Bosch HIGH SMOKE NUMBER 7 models

Source

Information for the HIGH SMOKE NUMBER 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