A heat pump system for a motor vehicle comprises at least two heat exchangers 10, 12, through which, for heating and/or cooling the motor vehicle interior, a flow is conducted, and at least two coolant circulations 14, 16 separable from one another, of which at least one is connectable, independently of the other coolant circulation, with one, two or more heat exchangers 10, 12 such that through these, in the presence of a connection with two or more heat exchangers 10, 12, a flow is successively conducted and the other coolant circulation is connectable with at least one heat exchanger 10, 12.