It's been an interesting few days. I got the Fahrenheit installed last weekend, and while it was putting out pretty decent heat, it wasn't burning worth a crap. The door glass turned black after a few hours and the inside of the firebox looked darker than Kentucky Mammoth Cave at midnight during a blackout. I found an area of the door gasket that was a bit marginal. I replaced that, gave myself a pat on the back, lit it back up and came back a couple hours later and found the same thing - black glass and a filthy firebox. To top it off, the combustion blower was starting to develop a nasty whine. I shut it down and called it a day. The next morning I called the folks at Fahrenheit about the combustion blower. They had them in stock, and since I'm fairly local to them I swung by their offices and picked up a new combustion blower. Got to pick their brains a bit and look around their factory. Great group of people out there. ot home, swapped the combustion blower, fired it back up and.... still burning dirty, but it wasn't as bad as before. The whine from the combustion blower was gone though. I dug into it a bit more and pulled the burnpot assembly out. The folks at Fahrenheit had told me about making sure the "back wall" was clean. I'd given it a few good whacks when it was still in my garage and some stuff fell out, but this time I went a bit further. I pulled at least two quarts of junk out of the back wall. So much for thinking I had it clean. I scraped the burn pot, put it back together, fired it up and.... still burning dirty. About this time I started bugging a fellow forum member (DexterDay) as he has a slightly newer version of the same unit I have. He gave me quite a few ideas to look for. Out came the burn pot assembly again. Off came the side panels and back panels. Off came the extended hopper and the top panel. One thing I hadn't considered was an air leak in the hopper. I don't know if the extended hopper I got with the unit is homemade or the actual Fahrenheit OEM unit. Based on the holes and notches cut in various places I'm thinking it might be a homemade unit. I also found the hopper lid safety switch had been bypassed. I'm not much of a fan of bypassing any safety control on a permanent basis. I filled the top row of holes in the burn pot with furnace cement (Dexter's idea), put a small bead of high temp silicone around the flange on the burn pot frame where the combustion air comes in (to make sure the air went into the pot and not out the sides) and reinstalled the burn pot assembly. I replaced the ash pan gasket, even though the old one passed the dollar bill test. Figured what the hell, I've done everything else. I removed the extended hopper as that thing has too many leaks for my liking (based on looking at the seams with a light inside it). I replaced the cleanout gasket on the left side of the unit below the control panel, hooked up the hopper safety switch, put it all back together, loaded it up with a bag of Somersets lit it off and.... Its finally burning clean! After 3 hours, the glass is starting to get that nice whitish film at the top and the inside of the firebox is starting to turn that nice shade of white/gray. The ash is light and fluffy and blowing around the inside of the firebox. No visible smoke at the exhaust like there was before. Best part is that its 20 outside and 68 (and climbing) inside. Thanks to DexterDay for his advice regarding things to look for on the unit and the burnpot modification. I think the burnpot mod provided a lot of benefit. And thanks to all the posts that say "if you think it's clean, think again". I wish I'd thought that while it was still out in the garage.