| 摘要 |
PURPOSE:To stop combustion when preset heat-up condition has been achieved and burn a burner when the temperature of hot-water has become low by providing at least two sets of temperature detectors on the chord of a water discharging plug. CONSTITUTION:Respective outputs of two sets of temperature detectors are inputted into a differential amplifying circuit 17 through amplifying circuits 15, 16, an average temperature is obtained in an average value operating circuit 18 to compare the output with the temperature preset in a temperature setter 19 in a comparating circuit and detect a heat-up temperature and the valve is closed by a driving circuit 21 to stop the combustion of a burner. When the hot-water is not used immediately after finishing heat-up, heat is dissipated from a bathtub 8 and a heat exchanger 3 and hot-water temperature is reduced, then, hot-water temperature becomes uniform when a time has elapsed by the diffusion of the hot-water. In this case, the average temperature of two sets of temperature detectors 13, 14 is being operated in a control circuit 4 and combustion may be restarted by opening the valve 5 when the average temperature has become lower through the set value by a given temperature, therefore, comfortable hot- water having a temperature within the temperature range of a given width may be obtained at all times after the heat-up of the hot-water. |
