Water purifier and method for controlling same

A method for controlling a water purifier that includes a water tank having a cold water path inside the water tank, a coolant inside the water tank, a cooling device including an evaporator inside the water tank through which a refrigerant flows and a compressor that is operable to compress the refrigerant so that the cooling device is configured to cool the coolant so that the coolant cools water flowing through the cold water path, a temperature sensor configured to detect a temperature of the coolant and output coolant temperature information about the detected temperature of the coolant, and an agitator that is operable to agitate the coolant, the method comprising:

• based on the coolant temperature information output by the temperature sensor indicating that the temperature of the coolant is lower than or equal to a preset ice-making temperature,
• performing a first mode of simultaneously operating the compressor and the agitator;
• after the first mode, performing a second mode of stopping the operation of the agitator and continuing the operation of the compressor for a preset ice-making time so that ice is made around the evaporator after the coolant is cooled to a temperature being lower than or equal to the preset ice-making temperature;
• and
• after a preset ice-making time from when the operation of the agitator was stopped, performing a third mode of simultaneously operating the agitator and the compressor so that the ice made around the evaporator is maintained in a frozen state.