I'm looking at a Fisher fireplace insert and wondered if anyone has had experience and can tell me pros/cons. My current fireplace chimney is tile lined and is in very good condition. The original damper was rusted out so several years ago I had a top damper installed (the kind you pull down and tighten from the inside). The current owner of the Fisher said he never lined his chimney as I was thinking I would need to do, and has operated the stove for several years without a separate lining. Is this a safe installation for me to consider? It's been very cold here in Iowa (-22 without wind chill!) so if I could pick this up tomorrow and get it installed I would be happy and needless to say much warmer! BTW, just had my chimney cleaned this fall so there is no build up.