Pb Low

Boiler Fault Code Pb

Also written as PB — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Pb 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 heat pump has temporarily paused its operation to prevent internal components from freezing during extremely cold weather. (As reported on Ideal HP290)

Pick your boiler brand for the Pb fix

Ideal Pb 1 model

Source

Information for the Pb 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