Hi I'm completely new to this forum, fireplaces, stoves and inserts. I purchased a 1700sq ft house ( about 1200 sq ft is on the same floor as the fireplace and the rest is upstairs ) 2.5 years ago. I'm assuming I'd want something that will heat up to 1800 sq ft or so. My main heat source is an oil furnace. There's an unused fireplace in the living room that was put in around the 60s or 70s. The fireplace is missing the damper. It's been sealed off since we moved in to help reduce heating cost. After a fair amount of research I've decided I would rather use the area for a wood stove or insert because they're much more efficient and having a heat and cooking source that doesn't depend on electricity would be awesome. Upon initial inspection I found what I believe is a heatilator. I have a hearth that's 16" and 12" off of the floor. The fireplace opening is 36"L x 28"H x 16"D on the top and 22.5"D on the bottom. The back is 27"W for the first 14 inches from the bottom then begins to taper up and toward the opening to 31"W. If you're familiar with heatilators I hope these dimensions help, I did my best to describe it . I will include a few pictures to help visualize. The damper hole is 9W x 27 tapering to 15W. There's what I believe is the smoke shelf above the damper? The flue is Terra cotta lined with an ID of 6 5/8 x 11 3/8. I'm guessing I'll have to ovalize a flex liner to get it inserted? I was originally looking at a medium sized stove with a height of 28" but after some thought it seems it'll be some trouble getting the flue liner attached and overall just be a tight fit. I also haven't found any other stoves under 28" that are the size I'd prefer. Can I install an insert while keeping the heatilator intact or do I need to rip it out? Can they be cut out in sections? Will the brick behind the heatilator need to be protected by fire brick if it's exposed? Should the vents be closed or doesn't it matter? Can I cook in an insert? I haven't been able to find a model number for the heatilator. I'm sure I'm not the only one that has dealt with a situation like this and I'd like to hear everyone's thoughts. I'm on somewhat of a budget. I'd rather not go above $2,000 or so but I will go up to $3,000 if need be. I'm in the natural gas industry and my dad and I are pretty handy guys and catch on fairly quick when it comes to learning something new. We do just about everything ourselves. Any help would be much appreciated! I'd love to start using this fireplace again, just not in its current condition. I'm also looking forward to lower oil bills in the future! . Thanks in advance to everyone and anyone that can help with this!