Long time listener first time caller

Hello all, I have a USSC American Harvest 6500. I just installed it a month ago. Well last night my fiance' texts me ( i work out of town during the week ) and says the basement is full of smoke. She turned off the 6500 furnace about 15 mins prior cause it was too hot. Well than the draft fan shut off before the fire went out so the room filled up with smoke. this is the 2nd time its happend this week. Does anybody know what causes this? thanks for the help

I'm not really sure what would cause this but what makes the draft fan turn off is the temp sensor that is just downstream of the draft fan in the exhaust if you remove the back cover to the furnace you should see it i'd just start by checking the wires that go to it. in the mean time if she wants to shut down the furnace try opening the hopper lid this will stop the auger and just let the fire burn out that way in fact that is always the way i shut down my stove because i think it cools the stove faster that way.

thanks for the info...I'll try that

I suspect you are burning wood pellets and they take forever to burnout and stop making smoke. There isn't enough heat produced to keep the exhaust fan on but the darn pellets keep making smoke. Corn doesn't do that.
Like "the bone" says if your hopper lid has a safety switch that turns off the auger when the lid is up, that should stopped the auger from feeding pellets and keep the exhaust fan on long enough for the fire to burn completely out. If there isn't a switch in the auger circuit that will turn the auger off, add one.