A dishwasher includes a tub, a spray arm, a sump, a pump body, the pump body including a partition between first and second chambers, a communication hole in the partition that communicates with the first and second chambers, a pump flow path that connects the sump to the first chamber, an arm flow path that connects the spray arm to the second chamber, an impeller in the second chamber, a heating unit to heat water in the first chamber, a steam flow path that connects the first chamber to the tub, a connection flow path that connects the steam flow path to the arm flow path, and a flow path valve configured to close the steam flow path based on water being supplied to the connection flow path, and to open the steam flow path based on a lack of water being supplied to the connection flow path.