I'm getting a little confused. Most people here seems to be talking about burning in the 250-400 range and I see several people say they get really worried when their stove goes over 650. My stove manual says that a low burn is about 300 degrees, a medium burn around 600 and a high burn around 800. So why should I be getting nervous if my stove goes over 650? I've got a 1991 Avalon 991E, installed directly into the flue of an existing fireplace, fully lined. I'm not the first owner of the stove, but I do have the original paperwork and manuals for it.