| 摘要 |
PURPOSE:To increase the temperature of stored hot water and to make it sufficient for the hot water feeder to have a small hot water storage capacity by a method wherein a heat pump and the combustion hot water feeder are used such that water is heated by the heat pump in the initial stage of operation and after that, the heated water is furhter heated by the combustion hot water feeder. CONSTITUTION:When the temperature of hot water detected by a temperature detector Th3 is, for example, less than 35 deg.C, a control circuit 18 drives a compressor 7 to thereby operate the heat pump 1. Further, when the temperature of hot water detected by the temperature detector Th3 becomes 35 deg.C or when the open air temperature is so low that the temperature of hot water detected by the temperature detector Th3 is lower than 35 deg.C even if the time counted by a timer 20 reaches a predetermined value, the compressor 7 is deenergized. Then a gas burner 9 of the gas hot water feeder 8 is ignited and the temperature of the hot water is elevated by the heat exchanger 10. |
