Hi Glacial Hills, Several nights ago I fired up my vapor fire 100 for the first time. I had a water tank hooked up to it (I ordered the hot water coil option), but I have not connected it to ductwork yet (I'll get that done this week), so I cheated by connecting a manual switch for the fan instead of the auto switch on the side of the furnace. I used 3 pieces of junk wood for the first fire, and set the temperature knob all the way to low. The lights on the computer came on and the air damper opened up all the way. 45 minutes later, the damper was still open all the way. It seemed like the furnace was not able to come to even it's lowest set temperature, or something was wrong with the computer or sensor. Then I added a nice dry piece of ash to the fire, and within 15 minutes, one of the lights went out and the damper closed part way, and the smoke disappeared! I was watching the top of the chimney, and I was looking through the draft damper. When all four logs had burned up, the insulation around the secondary burn area was still white, and the inside of my stack was absolutely clean. I'm looking forward to a colder night so I can really fire the thing up. I am most impressed by how simple this thing is compared to other gasifiers, and how well built it is. I wish there would be a way for me to watch the secondary burn happen. I'm sure that opening the door makes it stop completely, so there is no way to get a look up were the sensor is. I asked Daryl why they couldn't give a sight glass into that area, and he said they tried it, but it gets a white film on it so it became useless anyway. I was impressed with these down-draft boilers that have a lower door you can open to observe the secondary burn. I will post again after I have had some real experience with this thing, but so far as you were, I am very impressed!