Yesterday we pulled out the old zero clearence wood burner. My new pacific energy summit insert is now waiting to be installed. Just have to weld up brackets to keep the old chimney up and then insert the 25' 6" flex liner kit into the existing10" stainless chimney. Also if any tips on using the existing outside air intake on the left side of the box let me know. It does talk about it on page 18 of my manual but if you have experience let me know.