Water purifier and method for controlling the same

A method for controlling a water purifier including a water tank divided into a first water tank in which water is storable and a second water tank in which water is storable, a water temperature regulator positioned between the first water tank and the second water tank so as to contact the water stored in the first water tank and the water stored in the second water tank and configured to change a temperature of the water stored in the first water tank and a temperature of the water stored in the second water tank, a first water outlet valve configured to output the water stored in the first water tank, and a second water outlet valve configured to output the water stored in the second water tank, the method comprising:

• based on receiving a water outlet command from an input interface and determining that the first water tank is being cleaned and the second water tank is not being cleaned, opening the second water outlet valve to output the water stored in the second water tank;
• based on the water stored in the second water tank being output, opening a water inlet valve to supply water to the second water tank;
• based on water being supplied to the second water tank, cooling the water stored in the second water tank with the water temperature regulator;
• and
• based on an elapse of a reference time since the first water tank was cleaned, controlling the second water tank to be cleaned,
• wherein a temperature of the water stored in the first water tank and a temperature of the water stored in the second water tank are adjusted to a same temperature by the water temperature regulator.