A plumbing fitting having a body and a housing located in the body that includes a first inlet for receiving the first fluid, a second inlet for receiving the second fluid, and a mixing chamber. The plumbing fitting includes a first flow control valve operatively coupled to the housing; a second flow control valve operatively coupled to the housing; and an actuator assembly configured to move the first flow control valve relative to the housing to control flow of the first fluid from the first inlet to the mixing chamber, such that the first fluid exerts substantially no net force on the first flow control valve, and configured to move the second flow control valve relative to the housing to control flow of the second fluid from the second inlet to the mixing chamber, such that the second fluid exerts substantially no net force on the second flow control valve.