Hello - I am staying at a friends place. I have successfully used the fireplace before (with permission of course). Now when I try to light a fire smoke came through the front vents into the room instead of up the flue. It has a damper pull AND a lever on the front which I pushed to the right before starting. I also used a rolled newspaper to warm up the flue as I do at home. The box has baffles but I do feel cold air coming into it. Any suggestions?