I have a VC Encore 2n1 that I have had for a couple of years now. I have run it with the catalyst in place until recently, when I decided to try the non-cat mode. My question is why do I see more smoke coming out of the chimney when the bypass damper is closed than when the damper is open without the catalyst in place? What is the point of using the system in non cat mode with the damper closed if I get cleaner burning when the damper is opened?