I bought a used earth stove from a guy who said it worked fine, but was switching to another heat source. I have another pellet stove, so i have a little experience. I installed it, similarly to my first stove. I have cleaned it from top to bottom, seals look good, only a short run for a chimeny with no 90 deg bends. Motors all seem fine. I am getting the smell of smoke when there is no wind, and with the slightest breeze, smoke billows from hopper and fans. Stove is virtually unusable. Is there a flap or something that is supposed to prevent smoke from coming back through the auger? Any ideas?