Hello All, I'm new here on the forum, though I've been reading posts during the course of my research, and have found them to be very informative. It's nice to have a place where experience could be shared. I've run across an issue that I'm sure that I'm not alone in experiencing. I have a fireplace that my father built about 30-40 years ago...brick chimney...flagstone veneer fireplace that's the width of the room (13.5 feet). He put a heatilator type heat exchanger steel box in it that is huge. The front of the fireplace has a 43" opening and the back is at approx 34" wide. I've talked to a couple of dealers about inserts. After explaining what I had, one dealer said they don't install inserts into manufactured fireplaces. Another dealer would not consider putting a Lopi Freedom Bay in the fireplace because it's considered zero clearance and the Freedom Bay is not rated for zero clearance. I really don't believe that this is a zero clearance firebox. I am looking into a fireplace insert and I'm going for the largest unit that I can since the fireplace can more than handle the size. I've narrowed my selection down the 3 models the Lennox C310, the QuadraFire 5100, and the Lopi Freedom. The Lennox, while seeming to be good units, don't appear to have much dealer support in my area, so I can't get an answer on them. The Quadrafire dealer didn't seem to think that my setup would be an issue, but the Lopi sales rep said the Freedom Bay would not work because it's not rated for zero clearance and of course their concerned about liabiltiy. I was strongly leaning toward the Lopi, but I don't understand, how one unit can be ok, and another not. Your thoughts would be greatly appreciated.