| 摘要 |
PURPOSE:To facilitate a gas pressure adjustment and prevent a combustion from being restarted when a user fails to switch off signal of a gas pressure adjusting means is by a method wherein a maximum gas pressure adjusting means and a minimum gas pressure adjusting means are provided and their values are read into a micro-computer. CONSTITUTION:When a first switch 11 is turned ON, a micro-computer 13 may output a signal to cause a gas proportional control valve 1 and a fan 5 to have a maximum value to be outputted to a valve driving control circuit 2 and a fan control circuit 6 so as to adjust a maximum gas pressure. As a second switch 12 is turned ON, a signal to cause the valve 1 and the fan 5 to have a minimum value is outputted to the circuit 2 and the circuit 6 and then a minimum gas pressure is adjusted. First and second switches 11 and 12 are turned OFF together, an output for variably controlling a combustion of gas is outputted to the circuit 2 and the circuit 6 in such a way as a temperature of a thermistor 9 having detected a temperature of hot water to be fed becomes a predetermined temperature. Thus, the first and second switches 11 and 12 are turned ON, a simple gas pressure adjustment can be carried out and a combustion is not started when the switches are not turned off, resulting in that a safe operation can be assured. |
