It has been well documented on this site that learning to run your new system involves a learning curve. I noticed a build up of creosote in my unit in the left rear corner near the fan and internal air chamber. Having run a gassifier before I had an idea of the cause, but before I dug into the problem I emailed Profab for direction. That afternoon, I received a phone call from their tech department. Now that's customer service! The gentleman I talked with was extremely helpful and zeroed in on what he thought the issue might involve. He asked the typical questions: (length of wood, moisture content, how full am I filling the unit, etc). We concluded that there are two issues creating my problem. (overloading and warm temps) 1. The temps here in Maine (Oct and Nov)have been in the 50's and 60's (shoulder season) and we all know gassifiers don't like those warm temps- they want to burn hot, burn off gasses, and burn down to a just a coal bed. Temps now in the 20's and teens at night. 2. Too much wood in the fire box doesnt allow for #1 - hence a build up of creosote and that glassy look when you open the door. Last night I filled the firebox 1/2 full hoping it would run for 12 hours in 22 degree temps. This morning I had just a bed of coals in the unit and it held the temp. at 180. As the tech said, "You will learn to play the game of putting in just enough wood so the unit can run efficiently." It was nice to also see the creosote was not wet and glassy, but dry .Today, I will remove the fan and flapper in the back of the unit and make sure there is not a creosote blockage - the way the unit is gassifying, I think I am ok. I just thought I would pass on my experience in hopes it might help someone else with a gassifier. Kudos to Profab for their customer service!