| 摘要 |
PURPOSE:To simplify the structure of the device and to accomplish a water level control with good accuracy by driving an electrically-driven type switching valve on the basis of a signal from at least one of a water level sensor and switching means. CONSTITUTION:A control circuit 4 generates an output on the basis of an output of a water level sensor 5 to actuate a drive circuit including a power amplifier and the like for supplying power to actuate a switching valve 122. The switching valve 122 which has been closed up to that time is opened and water is supplied into a water storage tank 1 through a hot water supply pipe 120. When, in accordance with the water supply, the float 5b of the water level sensor 5 rises up, the output of the sensor 5 is turned off at a predetermined water level. In this case, power supply to the switching valve 122 is stopped, the switching valve 122 is closed, and hot water supply from a supply hot water heating unit A is interrupted. Upon this occasion, in a case where the control circuit 4 does not interrupt the output even if the defined water level is exceeded due to the fault of the water level sensor 5, switching means 8 is driven and opened by a float 6 and power supply to the switching valve 122 is interrupted, and hence the switching valve 122 is closed. |
