My fireplace has a small lever on the left side of the metal case. I believe the lever is for the fresh air intake, but do not know in which position the vent is open. Can you help?
either stick your hand up the chimney and feel a metal plate(closed or no plate(open) or you could bend your butt over and take a peak see up the ol Santa exit so see if its open..maybe just light a match and see if you get draft(open)