A: Dear JJ, There is no need to close the damper below your Chimney Balloon. The Chimney Balloon is doing the job of the damper and quite frankly it is doing a better job than the metal damper could anyway. So closing the damper after the Chimney balloon is installed is like closing a screen door on the inside of a submarine.
However, You can have the damper closed if you have the Chimney Balloon in there far enough to close it. There are a few things to keep in mind though if you do decide to close the damper. If you try to force the damper closed it may put upward pressure on the valve section of your Chimney Balloon. That is a little tough on your Chimney Balloon since it puts undue pressure on the valve and Chimney Balloon.
The other issue is if you close your damper you may forget you installed the Chimney Balloon and just open the damper and start a fire.
Personally, I leave my damper open and leave the inflation tube attached, so it dangles just above my head when I open the glass doors to the fireplace. With this solution, I still have no draft problem and I haven’t accidentally melted a Chimney Balloon yet. – Jason