I cleaned out my MES about 3 weeks ago and I was reseasoning it tonight .I put some wood pellets in and after about 10 min. i went out to open the top vent a little more.(From halfway to full) And I had an explosion sounded like a fire cracker went off and a blue flame shot out of the vent. Scared the s#@t out of me. I unplugged it going to go back out and see if it still works in a little bit here. The only thin I can think of it was a sudden rush of air, it is a little windy. It even scared the wife and she was at the other end of the house.