| 摘要 |
<p>PURPOSE:To prevent a tank from being abnormally heated when hot water operation is done without water in the tank CONSTITUTION:Temperature detector means 18 provided in a tank on-off controls a heater 7, and a controller 19 interrupts, when there is shorter than a predetermined time the temperature of the temperature detector means 18 reaches empty boiling detection temperature higher by a predetermined temperature than unnecessary heating temperature (off temperature of the heater 7) since the temperature of the temperature detector means 18 reaches the unnecessary heating temperature (off temperature of the heater 7) and the heater 7 is turned off, or when the temperature of the temperature detector means 18 does not reach the empty boiling detection temperature, power supply to the heater 7 thereafter.</p> |
