A coolant circuit, particularly a coolant circuit comprising a plurality of partial circuits 1, 2 and 3 of an internal combustion engine 11 having a main coolant circuit 1 and a heating circuit 2, and a coolant delivery pump 5 disposed at a rotating actuator 4, wherein the rotating actuator 4 comprises a rotary slide housing 20 having a plurality of connections 8a, 8b, 9a, 9b, 10a through which a coolant can flow, and a first and at least one second rotary slide 6 and 7 which is rotatably mounted in the rotary slide housing 20 and has at least one rotary slide flow opening 8, 9, 10 forming a flow path, and wherein the connections 8a, 8b, 9a, 9b, 10a can be brought into an at least partial overlap with the rotary slide openings 8, 9, 10 by a rotating movement of the respective rotary slide 6 and / or 7, wherein a first branch 1a of the main coolant circuit 1, which leads from the internal combustion engine 11 via a main cooler 12 to the main cooler connection 8b of the first rotary slide, can be controlled by the first rotary slide 6, and a second branch 1b of the main coolant circuit 1, which leads from an outlet 21 of the coolant delivery pump 5 to the internal combustion engine 11, can be controlled by the second rotary slide 7.