Question: I recently purchased a Hearthstone Sterling B-vent stove. I have an existing outside masonry chimney with a 6" flue (terra cotta). The stove will be installed on the first floor of a 2 story house. It is approximately 20' from the crock to the top of the chimney. The stove exhaust will be horizontal. The existing exhaust pipe is 4". I have a 6" crock. I need to know how the heck to install it. Do I need a liner or can I just run stove pipe thru the crock and end it at the flue or do I need to run up 20' with a liner. If I need a liner how do I buy it? does it come in 20' lengths, How do you attach it to the top of the chimney? Is it flexible? I'm lost. Any very specific help would be greatly appreciated? P.S. Are there some type of installation kits. Hurry up getting cold here in PA!! Answer: You need to run a 4" Flexible aluminum liner down the existing chimney. This flex-liner is available at some hearth shops and also at your local heating supply. This will then be connected to the stove. A pice of 6" black pipe can be installed over the flex line inside the home to dress up the installation.