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

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

Blocking High

Boiler Fault Code Blocking

Also written as BLOCKING — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

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

Most common meaning Your boiler has detected an issue with the air supply or internal startup signal, causing it to lock itself out for safety reasons. (As reported on Potterton Prima 30B)

Pick your boiler brand for the Blocking fix

Potterton Blocking 1 model

Source

Information for the Blocking 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