A circulation pump for a conveyed liquid is provided. The circulation pump has an electric motor, which is electronically commutated, has a rotor, a stator and a motor circuit. An impeller is connected in a rotationally fixed manner to the rotor. The electric motor has an evaluation device for determining a flow rate of conveyed liquid through the circulation pump from a rotational speed of the rotor and/or a power consumption of the electric motor. At least one signal output is provided, by which a flow rate signal and/or flow rate-dependent switching signal can be supplied by the circulation pump.