HEAT STORAGE WATER HEATER

PROBLEM TO BE SOLVED: To provide a compact and efficient heat storage tank by using a vacuum heat insulating material.SOLUTION: Single or double vacuum sections 30, 31 are provided on an outer circumference of a hot water storage tank, and a heat insulating material is simultaneously overlapped and enclosed in the vacuum sections, to enhance functions as a heat storage tank. In order to prevent heat dissipation from a heat storage section to the outside, a vacuum section formed with one or two gaps is evacuated while simultaneously filled with a heat insulating material such as glass wool, a polyester heat insulating material, urethane foam or a vacuum heat insulating material containing silica, and a reflective composite material such as an aluminum foil. Thus, the dissipation, emission and radiation of energy to air are prevented. Water feeding and tapping means is held outside the heat storage tank when the means is unnecessary, that is, the means is used only when feeding or tapping clean hot water or city water, thereby heat conduction is prevented and heat emission and radiation from the whole heat storage tank are prevented, and durability in long-term use is imparted to the heat storage tank. Consequently, the heat storage tank is configured to use the second midnight power, as measures for cost reduction, COreduction and low carbon emission.