| 摘要 |
<p>PURPOSE:To suppress the consumption of a useless power during a non-use for a long period and to enable the feed of sanitary water by a method wherein control is effected such that when no flow rate signal is generated for a given period starting from a point of time when a hot water tank becomes full of water, a motor-operated water feed valve is closed, a heat generating body is turned OFF, and a motor-operated drainage valve is brought into an opening state. CONSTITUTION:When a hot water storage tank 1 is emptied and a water feed switch is turned ON, a motor-operated drainage valve 7 is closed, and a motor-operated water feed valve 6 is then opened. In which case, a flow rate detecting signal from a flow rate detector 9 is inputted to a control device 8 until the feed of water to the hot water storage tank 1 is started and the tank becomes full of water. After flow rate detecting signal disappears, namely, it is detected that the tank becomes full of water, control of a heat generating body 2 is started, and a 48-hour timer is started. It is discriminated by the presence of a flow rate detecting signal whether hot water is fed through a faucet 3, and when hot water is fed, the 48-hour timer is reset. When hot water is not fed, after the 48-hour timer is timed UP to close the motor-operated water feed valve 6 and turn OFF the heat generating body 2 and hot water is cooled for 72 hours, the motor-operated drainage valve 7 is opened, and hot water in the hot water storage tank 1 is drained.</p> |
