GW1949 unusable due to downdraft

[Eriks Goodwin]

I installed a brand new GW1949 pellet stove and cannot use it due to horrible downdraft issues.  First, I'll explain my install--then I'll ask for advice from you fine folks.

The GW1949 stands in our great room with the requisite amount of non-flammable brick base and proper spacing from the rear wall of the house behind the unit.

From the top of the stove, using 3" pellet pipe (double-walled) the pipe immediately makes a 90 to go through the wall and into an adapter tee with cleanout.  The pipe then rises vertically, jogs outward by 24" to clear the fasia then continues vertically to about 24" above the roof surface and is topped with a wind-directional chimney cap.  Total rise from top of stove to cap is about 16'.

From the rear of the stove, I installed a 4" flexible duct to go through the floor, then run horizontally via SCH20 PVC pipe through the crawl space and through the front wall of the house.  The rear wall of our house is partially buried, hence the run of the duct to the front wall, which is above ground.  Thus the duct never rises above the intake on the stove (per the instructions for the fresh air supply).

I use a heat gun to light the stove--which I allow to run with no pellets in the burn basket until the top thermometer reads at least 200F.  After adding pellets and while igniting them, there is always smoke that comes from the draft ports, the middle chamber cover and the pellet chamber.  Once ignited, if there is no wind, it seems to work as expected.  Flue gas stays around 425F-500F, flames are visible through the sight glass, etc.

BUT, as soon as the wind kicks up, the flames cut back or disappear and smoke starts pouring out of the middle hopper cover and/or draft control openings.  To resolve this, I have to open a window near the stove which happens to be angled to "catch" the wind blowing by the house.

While trying to get it to work, I noticed at one point that the fresh air duct was extremely hot (blowback?) and at that point, I disconnected the fresh air duct and kept the window open until the stove went out.  Meanwhile our electric baseboard heat ran constantly trying to keep our house warm until we were able to close the window after the fire went out.

I have also noticed that the middle hopper cover gets rather hot--though I am not sure it if happens during "normal" operation (i.e., no wind outside) or just when backdrafting is occurring.

At this point, I am considering switching over to a fresh air supply that goes through the wall above the stove and that uses pellet pipe just to be safe--but right now it feels like throwing good money after bad.

Anyone have advice?  I want to love this stove, but right now its just a very expensive useless pile of steel.  :-(

[Eriks Goodwin]

I forgot to mention...  The stove is at about 8,034 feet in elevation; and winds here in Dubois, Wyoming regularly vary between 25 and 75 mph.