This may take a while..... I bought a log cabin in the CO mountains that had a Heatilator fireplace and a prefab stick built 19' chimney on the outside wall and a brick hearth inside and fake rocks on the outside. I recently had a small insert installed in the fire box along with a SS 6" liner in the original 8" flue. It puts out more heat than the Heatilator but not enough. About 1200 square feet, all cathedral ceilings with a loft over about half that area. I have been on this site and many others trying to decide what unit I want to buy. I have looked at OWB's, Max Caddy, Kuuma, Blaze King etc. Not sure what my best options are at this point unless I can figure out if I can use the existing chimney and a wood heater. This seems to be the best option-maybe. It would appear that the piping inside the chase is a Class A off the original Heatilator-or at least that is what Heatilator shows in their specs. So, here is my question. If I remove the brick hearth and modify the inside area with some sort of alcove, replace the pipe with a new class a inside the chase with some type of support for the class a, can it be made safe and also meet code? Or do I need to tear the chimney down and start over? There is no duct work in the house, so any of the other above options didn't seem very feesible and power outages are not uncommon. I will at some time in the future make this my retirement home so keeping the hot water lines drained on a OWB when I am not there didn't make sense. Not always having dependable power, not wanting to deal with generators, but having heat all the time-makes me lean toward a big wood heater. If the chimney chase needs to be replaced, then maybe the other options are the way to go. I look forward to the replies and appreciate the help.