Boiler Fault Code Flow sensor

Also written as FLOWSENSOR — same fault.

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

Fault code Flow sensor 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 The boiler is failing to register that water is moving through the pipes, so it has stopped heating to protect itself from overheating. (As reported on Potterton Envoy 30)