Just wondering what everyone's thoughts are on having to like a chimney they entire way to the top for Pellet stove use? Right now I have 3" pipe off the back of my stove up about 5' then into the wall and all the way out the chimney. I haveing tons of problems with air flow restrictions and have found out that the manufacturer suggest 4" pipe now instead of 3" which could be part of my problem. But also different dealers int he area are telling me different things as far as having to run the 4" the entire way out the chimney. Which is extremelly expensive and I have to wonder if some of them are in it for the money.