Question: I currently have a Pre-Way pre-fab fireplace and chimney in my house. The chimney pipe is tripled layer steel but I dont know the "class" or rating. It is 9 years old with moderate use.I am looking for some serious heat and am considering a woodburning insert or hearth stove. The existing fireplace opening is small which limits insert options. the hearth is 19" deep. Can the existing chimney pipe be utilized for a woodstove or does it need to be relined? Any ideas for a good stove to use? I live in Maryland. Thanks for your help. Answer: The Preway chimney is not rated for use with an insert, it must be lined. It is my opinion that all pre-fab fireplace chimneys should be relined if you intend to use a woodstove. These chimneys are not tested for this higher temperature use. An open fireplace takes lots of room air up the chimney with the fire, therefore keeping a cooler stack. Woodstoves limit the air, so the pipe is hotter. In addition, stoves have a higher risk of creosote and chimney fires than do fireplaces. Line the chimney with a 6" rigid or flex stainless steel liner... most people use a small insert model (prefabs usually have small fireboxes). Make certain to get a model which is approved for a pre-fab fireplace. Travis Industries and others make such models.