Boiler Fault Code Pump Overrun - Storage Tank

Also written as PUMPOVERRUNSTORAGETANK — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code Pump Overrun - Storage Tank appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is currently running its internal pump to move leftover hot water away from the heating components to prevent overheating, which is a normal part of the shutdown cycle. (As reported on Potterton Envoy 30)