| 摘要 |
<p>PURPOSE:To maintain the effect as an auxiliary heat source as much as the best state by providing a sub tank separately from a hot water storage tank, providing the auxiliary heat source in the lower portion, and providing an automatic switching valve between the connectors. CONSTITUTION:When the rising value of water temperature is low, an electric heater 17 disposed in the lower portion of a sub tank 18 is energized to heat water 12. When a hot water temperature detector 22 detects the prescribed temperature, the heater 17 is deenergized. Simultaneously, an automatic switching valve 21 is opened, the water 12 having heavy specific weight at low temperature in the tank 11 moves from the lower portion to the tank 18 side by the difference of the specific weight due to the difference of the temperature between the water 12 in the tank 11 and the hot water 23 in the tank 18, and the hot water 24 having light specific weight is circulated to the upper portion of the tank 11 side by the high temperature of the tank 18 side. When the water 12 of low temperature is detected, the heater 17 is energized, the valve 21 is closed at the time difference, thereby preventing the convection during the boiling.</p> |
