Help With Amana 90% Furnace

I ran into an Amana 90% Furnace yesterday (model # GUC090B35C / Serial Number 9101105998). The basement has been finished out fully, and is divided into a big family room with full doors to the upstairs.

There is a closet on 1 side of the family room with louvred doors out to the family room (closet room is about 7’ x 7’). On the opposite side of the family room is a kids bedroom. To get to the bedroom you have to go thru the family room (about 20’ x 20’). The kids bedroom only has 1 entry - thru the familyroom.

There is only 1 pvc pipe leaving the furnace / It goes out the roof and terminates with a “U-Shaped” elbow on the roof end. I don’t see a pipe in a pipe at the roof vent BUT I don’t see intake opening into furnace below.

I’m trying to find installation instruction on this unit and have had no luck.

Feel its totally wrong installation and improper C/A, but looking for info to see how its allowed to be vented.

That kinda puzzles me also the U bend on the roof is normally for intake sounds like they got confused. In my area the intake does not have to go through the roof. I presume the furnace is in the closet behind the louvered doors using the SQ FT area of the basement for combustion air. Not sure why you can not see the combustion intake on the furnace???

Geez Charlie,what a dimwit I am … Just realized the door was off the furnace when I got there and nowhere in sight. Looked on I-net; that model has louvred upper door … Duh.

Heres roof shot and furnace shot.

More than enough reasons to have HVAC service and repair … Leaks at condensate and inducer; clogged blower motor; boot on roof split; R/A grill too close to burners; location of unit & size of room for C/A requirements; etc BUT I was brain dead on C/A location




That is a upflow furnace and appears to have a return grill real close to the unit. Was there a knock out on the top left side of the housing the way they left it the combustion blower can draw from the burner area should in my opinion at least be outside and above the unit

Been there done that sometimes can not see the trees for the forest

Preston’s Guide lists that model as a 1992/93.

Thanks Linus … Also the gas valve was date stamped with 91/49

49th week of 1991 SO a double check on age