摘要 |
PURPOSE:To avoid generating the feeling of a cold air flow at the time of post-purge and prevent a combustor body from being overheated, by providing a maximum discriminating part for determining an upper limit for an integrating timer, and a minimum discriminating part for determining a lower limit for the integrating timer for the case where an operating switch is again turned ON after being once turned OFF. CONSTITUTION:A combustion timer 32 counts combustion time, and a calculating part 33 calculates a timer value for the combustion time. An integrating timer 34 determines a post-purge period based on the timer value sent from the calculating part 33, a period of time for which the timer 34 itself outputs a signal to a fan motor controlling part 29, and a calculated value stored when an operating switch 23 was turned ON in the preceding post-purge, and continues outputting an operating signal to the controlling part 29 for the post-purge period even when the switch 23 is turned OFF. A maximum discriminating part 35 determines an upper limit for the timer 34, whereas a minimum discriminating part 36 determines a lower limit for the timer 34 for the case where the switch 23 is again turned ON after being once turned OFF. |