We have a 1983 "King" model blaze king that has the oval cat. The problem I'm having is that the fire dies shortly after I close the door. I always make sure I have a good bed of burning coals and then I load her up. I've tried this every way I could from the thermostat set to either 1, 2 or 3 to the draft door being fully opened to being barely cracked, but the fire always goes out. What am I doing wrong?