Adapted my PE Summit to my fireplace with masonry chimney last year, stove burned decent but not as good as I know it could, I belive it is not heating up the chimney enough to get good draft. Until I had it roaring it would blow back on me. Going to drop 6" Metalbestos down the 12" square flu (approx 30' straight run) and build a metal stand in firebox to support new flu, have to break the smoke chamber up because the angle of it will interfere straight down. Any advice, someone told me after install is all complete to fill voids in entire chimney with vermiculite??? From top to bottom by pouring it down the chimney and rodding it in. So that the metalbestos will be insulated. Firebox had a rotted out heatalator in it that I had cut out. Summer project!! sweating my ass off to keep me warm, how do you spell ironik??????