I have been having problems with the Auger on my 25-pvdc. Last night after pulling the Lower Auger, cleaning the tube and replaceing the motor. After that the Power went out, I had smoke coming from the OAK, and the two small square holes below the front shelf. I have a 6 inch vertical out to back to a Clean out tee then up for 3 feet. I would think that is enough for an up draft. Am I wrong here. Also of note, When the Auger motor failed the night before the Pellets "back burned" all the way to the bearing on the lower Auger. I am surprised it did not burn into the Upper auger and to the hopper. I guess I was Lucky.