In the RECIRC position, the pump receives water from the livewell only. Outside water is blocked. In the EMPTY position of systems V2& V3, water is allowed to exit the livewell drain, but is not allowed to enter. For system V4, EMPTY allows water to pass in either direction When on plane, the AUTO position allows water to enter the valve and pump from both outside and from the livewell. When on plane, the outside port is closed to prevent water loss and livewell water continues to enter the valve and pump for recirculation.