| 摘要 |
PURPOSE:To remove combustion products as warned, and eliminate maintenance inconvenience by carrying out cleaning alone when detecting a harmful gas component having a specified warning density lower than a stop density and halting the supply of gas to a burner when detecting a harmful gas component having a density high than the stop density latter. CONSTITUTION:The density of a harmful gas component such as CO produced by incomplete combustion detected by a gas sensor 36 is compared with a warning density. If a harmful gas component whose density is higher than a warning density is detected continuously three times and over, the CPU displays a warning that come cleaning time has arrived to remove combustion products, and resets the number of detection 'n' to 0, thereby returning control operation. If a cleaning warning is indicated, the CPU compares the harmful gas component detected by the gas sensor 36 with a stop density. If the harmful gas component whose density is higher than the stop density is detected continuously more than three time, abnormality indication will be made by a buzzer or the like. As a result, solenoid valves 22 go 24 will be closed respectively and after purging will be carried out for a specified time, thereby halting every control operation. |
