My main question is: my current flue is 6" I believe - can I step the 3" exhaust on the outlet of the pellet stove to this 6" flue? I know pellet stoves have blowers to assist in draft, but I am not sure if I'm asking for soot to build up near the chimney. If I can't do that, would it be better to run a 3" like to the chimney, or patch the chimney and do a separate outlet on the wall which is an outside wall.