Thanks, I don't know if it has a liner. I know it has a damper and it is definately lined with an offwhite "firebrick". Whats an insert? We just have the bare bones fire box ie no glass doors or jazz like that. I am sure it must have a liner, the house was built by a well respected builder in the area. We have used logs or wax logs all these years with no problem. The house smells fine (no constant smoke odor and smoke doesn't come into the house, which would indicate a chimney problem). We haven't had it cleaned for 7 years so I guess we better at least do that.