Each fireplace has a rating plate either inside the operating door or in the lower controls cavity. On that rating plate is your model number and serial number. Wood-burning fireplaces have a metal serial/model plate in the upper left side or right side of the firebox, or riveted on the smoke shield behind the screen. Gas burning fireplaces and inserts have a serial/model/rating plate in the lower cavity controls area. Gas stoves have a serial/model/rating plate attached to the back of the stove or inside the pedestal base.