Water mixing device and water purifier including the same

A water mixing device comprising:

• a cold-water module including a cold-water tank that accommodates water, a cooler that cools the water accommodated in the cold-water tank, and a cold-water temperature sensor that detects a temperature of the water accommodated in the cold-water tank;
• a hot-water module including a hot-water tank that accommodates water discharged from the cold-water tank, and a heater that heats the water accommodated in the hot-water tank;
• a flow channel connected to the cold-water tank and the hot-water tank to provide a passage through which water flows;
• a valve unit including one or more valve modules opened or closed to adjust a flow of water in the flow channel;
• and
• a controller configured to control the one or more valve modules,
• wherein the flow channel mixes water cooled by the cooler and water heated by the heater to provide discharge water, and
• wherein when the temperature of water detected by the cold-water temperature sensor is higher than a preset threshold temperature, the controller controls the one or more valve modules to prevent water from flowing into the cold-water tank.