I have a Rutland thermometer on the angled piece of my step top stove. I just added an Imperial thermometer to the pipe 18" above stove . Someone told me since it is double wall pipe to just add 100 degrees. My stove top readings are 600 and my pipe is just under 200 on the thermometer. I can see some lazy upper air tube activity and the flames seem to be cruising toward the glass and up over the insulation on the firebrick. on the right side of the stove the glass is all black and the fire bricks are also. but the left side of the stove is clean glass and brick . What are everones thoughts on this. The stove is new the chimney is new and all this is new to me. I am burning white birch and beech right now. Oh and the chimney is 12' straight up through the roof .