I have a Heat & Glo 6000TR-OAK-IPI. I personally ensured the walls, ceiling and floor were insulated properly prior to the installation of the fireplace (was new construction). I recently installed a 97% efficient furnace with a variable speed fan that runs 24/7. A huge draft has developed from the fireplace at the area of the access panel on the bottom front of the unit. I have no air from outside the shell. I have accessed the area surrounding the fireplace and there is not cold air in this area. The air seems to be between the firebox and the shell. When sitting on the floor you can see directly out of the firebox to the vent on the outside. Heat & Glo stated that they do not make a damper for these fireplaces. So these are my questions:
1. Can there be a gap between the firebox and the outer shell where the vent is not seated?
2. Is there an aftermarket damper that can be purchased?
3. Can fireproof insulation be used next to the double walled vent pipe?
4. Do I have any hope of fixing this problem?