Does American Standard furnace model Freedom 80 have a cover in its filter opening?

SOURCE: I changed the furnace filter

does anything happen, i door that you removed might have a kill switch on it so if the door comes off or is not installed right the furnace wont light, let me know and maybe i can help. wally

SOURCE: I have a American Standard

Hello, The only time pvc is allowed is if the Furnace is 90% or greater in effiecency, the combustion gases are cooler due to the fact that two heat exvhangers are used. One pipe will be you air intake and the other the exhaust and they can be routed through the roof or sidewall. If the Furnace is 80% then you must use double wall vent pipe and have it connected to either a liner in a chimney or routed through a roof but pvc can not be used.