I stopped using Comfy Cozy last year, they do not give off enough heat for the $$ IMO, compared to other brands. We run our 25-PDVC at heat range 1, blower speed 1, with all other settings factory. This is year 4, and have never had a problem other than a stuck auger motor and an occasional E2 error on start-up.
I have a direct outside air pipe going into the inlet, which is the opening you see when you lift up the wear plate (the 'OAK' mentioned above). With the outside air inlet sealed (from the room where the stove is, that is), the exhaust/chimney pipe also sealed, and all your gaskets in good shape, the stove should operate as a sealed unit. If you are drawing air from the room, or from any source inside the house, there is the possibility for smoke to enter. If you have a clean stove, and good outside air coming into the unit, and all settings are correct, try a different brand of pellets.
I have a direct outside air pipe going into the inlet, which is the opening you see when you lift up the wear plate (the 'OAK' mentioned above). With the outside air inlet sealed (from the room where the stove is, that is), the exhaust/chimney pipe also sealed, and all your gaskets in good shape, the stove should operate as a sealed unit. If you are drawing air from the room, or from any source inside the house, there is the possibility for smoke to enter. If you have a clean stove, and good outside air coming into the unit, and all settings are correct, try a different brand of pellets.