| 摘要 |
PURPOSE:To prevent the danger, such as breakage, fire or the like, of an appara tus as well as the operation of an overheat preventing device before operating a filter sign device, by providing a plurality of safety means operated by an output signal from a pressure deciding means which decides whether or not a pressure is within a plurality of set pressure ranges. CONSTITUTION:A pressure deciding means 12 compares a pressure P, detected by a pressure detecting means 8, with the pressure range P1-P2 of a narrow pressure range setting means 9, the pressure range P3-P4 of a medium pressure range setting means 10 and the pressure range P5-P6 of a wide pressure range setting means 11 at all times. When P>=P2 or P<=P1, the pressure deciding means 12 outputs a signal to an alrming means 13 to inform the outside of a room of the clogging of a filter 6 however, the operation of the title heater is continued. When P>=P4 or P<=P3, the pressure deciding means 12 outputs a signal to an operation control means 14 and reduces the amount of combustion forcibly. Further, when P>=P6 or P<=P5, the pressure deciding means 12 outputs a signal to the operation control means 14 to stop the operation of the heater. |
