VERTICAL ELECTRIC WATER HEATER INCLUDING MOVABLE SEPARATOR AND BOILING METHOD FOR THE SAME

PROBLEM TO BE SOLVED: To prevent mixture of high-temperature water with low-temperature water during hot water supply, that is, water supply by dividing inside of a vertical hot water storage tank into a high-temperature water chamber and a low-temperature water chamber and varying the volume of each of the chambers, efficiently boil up high-temperature water, and achieve hot water supply at stable temperature.SOLUTION: This vertical electric water heater includes: a heating element 4 heating hot water while circulating the hot water by a pump 3 within the hot water storage tank 2 formed to have vertically long shape; a circulation pipe 6 connected to an upper circulation port 5 opened at an upper end of the hot water storage tank 2, capable of extending/contracting vertically within the hot water storage tank 2 and having a lower circulation port 7; the high-temperature water chamber HR on the upper side within the hot water storage tank 2; and the movable separator 8 vertically movably provided in the hot water storage tank 2 to variably partition the volume of the low-temperature water chamber LR on the lower side.