| 摘要 |
PURPOSE:To prevent excess heating exceeding a heating hot water set temperature by providing a first circulating pump and a first hot-water temperature sensor, connecting a heating circuit for connecting a heating load to a tank by a second supply tube and a second return tube, and providing a second circulating pump and a second hot-water temperature sensor. CONSTITUTION:Since a heating circuit for connecting a heat exchanger 2 to a heating load 3 is divided by a hot-water tank 5 on the way of its route, and a heat exchanging coil 11 is not arranged in the tank 5, and hence residual energy of the exchanger 2 after burning of a burner 14 is stopped is scarcely transferred to the tank 5. Further, when heating hot water is heated by the burner 14 and the hot water becomes a heating hot water set temperature, heating control of the burner 14 is stopped, a first circulating pump 6 is stopped and the hot water is circulated only by a second circulating pump. Accordingly, since the hot water is not circulated to the coil 11 of the exchanger 2, excess heating above the set temperature does not occur. |
