| 摘要 |
PURPOSE:To enable a faulty condition of a water level sensor to be detected by a method wherein a water level signal discriminating means may input a water level data to judge whether a combination of water level signals detected by a plurality of water level detectors is normal or not and then if the combination is abnormal, the means may output an abnormal signal. CONSTITUTION:A water level signal discriminating means 12 may input a water level data outputted by a water level signal inputting means 5 to judge whether a combination of water level signals detected by water level sensors 2, 3 and 4 is normal or not. If it is abnormal, it may output an abnormal signal. In this case, a normal combination of the water level signals has only four combinations. Thus, in the case that any of the water level sensors 2, 3 and 4 is faulty in their ON states or OFF states to show an abnormal combination, the water level signal discriminating means 12 may judge it and output an abnormal signal. As its abnormal signal is inputted to the operating controlling means 6, a water reduction informing lamp 7, a full water informing buzzer 11, a heater 9 and a hot water circulation pump 10 are terminated for their operations. Thus, it is possible to prevent the water reduction informing lamp 7 or the full water informing buzzer 11 from being erroneously operated due to a trouble of the water level sensors 2, 3 and 4. |
