Abstract: A water supply device disposed in a refrigerator door includes a first tank, a second tank and a third tank respectively disposed in the door, each of the three tanks having a pipe extending therefrom and each pipe having an outlet extending from an outer layer of the door, a first connecting pipe with a first one-way valve disposed thereto being connected between the first and the second tank, a second connecting pipe with a second one-way valve disposed thereto being connected between the second and the third tank, the first tank having a heating device disposed therein and only the first and the second tank being separated from an interior of the refrigerator by an insulating layer.