COMBUSTION DEVICE AND COMBUSTION CONTROL METHOD

PROBLEM TO BE SOLVED: To maintain a normal combustion state by a method wherein when CO concentration exceeds a reference value, by increasing an air amount, a combustion device is brought into a normal state, and when CO concentration exceeds the reference value from the combustion state, a feed amount of fuel is suppressed. SOLUTION: A CO sensor 18 electrically detects CO concentration during exhaust, a detecting output ECO is inputted to a CPU 4 through an A/D conversion part 16. The CPU 4 is provided with an input unit(I/O) 24 and various detecting means and drive circuits are connected thereto. A proportional solenoid valve drive circuit 30 controls the drive current of the electromagnetic solenoid of a proportional solenoid valve 32 arranged at a fuel system. The proportional solenoid valve 32 controls the feed of a fuel gas amount necessary to a burner and coupled with control of the number of revolutions of a fan motor 34, a maximum fuel feed amount is varied. A fan motor drive circuit 40 applies a drive current necessary to rotation of the fan motor 34. The number of revolutions is increased in a stepped manner under a specified condition through a fan motor drive circuit 40.