| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a storage water heater with a heat source part having improved durability and reduced running cost while reducing the unnecessary frequency of starting the heat source part during antifreezing operation. <P>SOLUTION: The storage water heater comprises a hot water storage tank 20, the heat source part 23, a circulation pump 25, a circulation water path 26, a bypass side water path 28, a three-way valve 29, and outside air temperature detection parts 30, 31. When the outside air temperature detection parts 30, 31 detect temperature lower than a first preset temperature, the three-way valve 27 is first changed over to the bypass side water path 28 to form a water path with the circulation water path 26 and the bypass side water path 28 and a lower region of the hot water storage tank 21 and then the circulation pump 25 is driven for antifreezing the circulation water path 26 utilizing the heat of hot water stored in the lower region of the hot water storage tank 21. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
