| 摘要 |
<p>PURPOSE:To prevent a tank from abnormally heated when hot water operation is done without water in a tank, CONSTITUTION:Temperature detection means 18 is provided in a tank, and when hot water operation is done with a heater 7, the temperature detector means 18 controls on and off of the heater 7. There is further provided a controller which interrupts, when there are continued successively by a predetermined number of times cycles where the time of one cycle of the on-off cycles is less than a predetermined time, power supply to the heater 7 thereafter.</p> |
