To provide a burner capable of determining whether it is normally ignited or whether its burning condition is normal or not, capable of quickly informing when detecting accuracy is lowered by dirt such as dust, and possible to be realized with simple structure at low cost.
A first threshold value X, with which a detection value A based on a detecting signal from a flame sensor (optical detecting element) of the burner is compared to determine igniting condition, and a second threshold value Y higher than the first threshold value X on an ignition determination side and lower than the maximum detection level of the flame sensor are set. When the detection value A exceeds the first threshold value X and the second threshold value Y once (after normal ignition) and, thereafter, becomes lower than the second threshold value Y in the condition that operation of the burner is not stopped, determination that the frame sensor is dirty is done, and an alarm informs a user of the device that the device is dirty. The user can quickly take measures such as cleaning of the frame sensor.
YUKI TOSHINORI
Kato Kazunori
Katsuichi Nishimoto
Hiroshi Fukuda