A pump includes: a pump housing having an inflow port, a first discharge port, and a second discharge port; a pump motor for providing a rotational force; and an impeller disposed in the pump housing and configured to pump water introduced through the inflow port. A planetary gear train includes a carrier connected to a rotary shaft of the pump motor, a sun gear connected to the impeller, a pinion gear rotatably installed in the carrier and engaged with the sun gear, and a ring gear engaged with the pinion gear. A rotatable valve disc is couple with the ring gear in the pump housing, and configured to close the first discharge port and open the second discharge port in a first rotation position, and open the first discharge port and close the second discharge port in a second rotation position.