In order to shift a rotation angle of a rotor to a region of a normal mode (for example, a region c) from a region of a heater cut mode (for example, a region e), the rotation angle needs to pass through a region where a flow rate of a refrigerant which is caused to flow through all branch channels becomes zero (a region d). When the refrigerant has a high temperature, there is a possibility of the refrigerant being not cooled, and boiling. Therefore, when a request to switch a normal mode and a heater cut mode is issued, permission/non-permission of switch of the mode is determined by comparison of a temperature of the refrigerant detected by the temperature sensor (26) and an upper limit temperature of the refrigerant.
