I installed a stove in my basement and decided to use and old piece on steel pipe for a chimney that runs up on the outside of my house(about 21 Feet in height) My problem is that it doesn't stay warm enough to keep a decent draft. The pipe is pretty heavy(7 inch OD and 6 5/8inch ID). Is there anything that i can do with this or am i going to have to take in down and start over.