| 摘要 |
<p>PURPOSE:To prevent an abnormal rise in water temperature around an electric heater during power supply suspension to an electric heater by installing a pump which produces water flow in a circulation passage designed to circulate the water in a water tank and a pump time lag shutdown means which shuts down the power supply to said electric heater latter after having stopped te power supply to the electric heater adapted to heat the water in said circulation passage. CONSTITUTION:When a timer setting means 14 is turned on, power is supplied to a pump 7, if the temperature of hot water in a bath tub detected by an incurrent water temperature sensor 5 is lower than the temperature of hot water preset by a hot water temperature setting means 13, then a water current sensor 6 is turned on. When the sensor 6 detects the generation of water current in a circulator 3, electric power is supplied to an electric heater 8. When the temperature of hot water in a bath tub 2 has reached the preset temperature, the power supply is suspended to the electric heater 8. At the same time, a pump time lag shutdown means 16 acts and allows the power supply to the pump 7 for a specified time even after the power supply to the electric heater 8 is suspended. As a result, the remaining heat of the electric heater 8 is cooled by the water flowing in the circulator 3. The water heated by the remaining heat is not allowed to rise to the temperature to which an overheat switch 9 actuates in the circulator.</p> |
