I have a brand new Quadra-fire 3100 LE. My avatar is a picture of the stove burning completely shut down. I checked the air controls and they work fine but my door fails the dollar bill test. That is, I can easily pull out a bill from the door when it is shut and latched. I think that must be why I cannot shut the fire down any further. I conclude that the handle needs to be adjusted. I thought I knew how to do that but cannot tighten the nut on the handle any tighter. So what am I doing wrong?