A pump assembly includes at least one rotatingly driven impeller (14) and at least one valve element (18) which is rotatable about a rotation axis (X) between at least two switching positions. The valve element (18) includes a first face side (22) which extends transversely to the rotation axis of the valve element. A suction opening (24), which is engaged with a suction port (26) of the impeller (14), is formed in this first face side in a central region. The first face side (22) includes a pressure surface which surrounds the suction opening (24) and is adjacent to a delivery chamber (28) which surrounds the impeller (14).