| 摘要 |
PURPOSE:To obtain the water heater capable of burning gas at a low temperature, maintaining the temperature of reserved hot-water at a constant value and uniforming temperature distribution by providing temperature control function and hot-water circulating function. CONSTITUTION:When water 3 is poured into a bathtub 2 to a set water level and a water level detector 11 is operated, a solenoid valve 10 for water is opened, a heater 8 is ignited and a pilot burner is ignited. A photoelectric conductive body 12 detects it and the solenoid valve 7 for main gas is opened to burn a gas burner 6. Simultaneously, a pump 14 is operated and hot-water is circulated through a heated water tube 4. When the temperature of hot-water in the bathtub 2 arrives at a predetermined temperature and a thermistor 15 detects it, the solenoid valve 7 for main gas is closed and the pump 14 is stopped. When the temperature in the bathtub 2 is reduced to a temperature lower than the set temperature, the solenoid valve 7 for main gas is opened to burn the gas burner 6 and the water tube 4 is heated again. |
