We moved into our house last summer. Just started using the fireplace, which has an insert. The blower is sucking air at the bottom, but air is not coming out the top. I took off both top & bottom covers and it seems that at the bottom, the fans suck the air in. But then the air is just blowing out to the left and right of the areas where the fan is. I blocked those areas and some air seems to be coming out of the top, but not as strong as I would expect. It seems to me like I need to put a piece of sheet metal over the left & right areas at the bottom. But I am also not sure about the 3 sliding levers inside the fireplace. One on the front seems to open or close holes along the front of the fire grate. Then one on each side L & R I imagine control whether air comes up the sides, but I cannot tell that they are doing anything. I have attached pictures. Any help would be appreciated.