M&S, I took a look at our 30'RSO with the two stage furnace and I have no open holes off of furnace all are connected to grey round flexible tubing. I have three grey flex tubes connected to back of furnace box and one more connected to the side of box. I could not really tell where they all go to as the basement is to full yet though plan to empty it soon for winterizing and will trace them then just for my own couriosities. I guess for yours I would call PI and check as that does not seem right to me and I would think a total open hole directly off of furnace like that would take away from air flow to rest of coach IMO. Please post what you learn.
Paul, Roxanne, Charlie, and Fritz the Siamese Cat.
2007 Excel, 30RSO, Demco Glide Ride, B&W Companion.