I'm unsure where to start, but this is my first post on the forum because I am simply dumbfounded and have no where else to look. I have a quadra-fire contour that I have been running for 12 years with no troubles. I meticulously clean it weekly and maintain anything that goes wrong as soon as possible, but this is a problem I had yet to see until now. I recently had issues with a lazy flame and the stove was burning the pellets quite poor, I turned off my stove and replaced the door seal + the pot seal, and also changed the switch #2 (for the air movement blower motor, not the convection blower) because I had it jumped to run all the time as it had failed and I was waiting for my new switch, which did indeed repair the problems. While I was piddling around I decided to replace my blower motor because it was noisy...efficient but noisy. I removed it and cleaned out all the dust and what not that had accumulated since the start of the cold season, installed the new one and waited for it to turn on. The blower turned on but something odd occurred to me, one of the heat exchanger flutes puts out little to no heat, while the one beside it doesn't blow at all! I didn't notice it before I installed the blower, but maybe this has been happening for a while, is it possible something somehow got into one of the flutes ie: a mouse, and if so why would heat be minimal from only one of the other flutes that is beside it? I tried to flash a light through the flue that isnt working but i cant see any light passing through it, I also don't have a compressor or anything of the sorts to blow air backward through the inoperative flue. As I said I am meticulous about cleaning my stove and though it is mid season the exchanger is still very clean. The inoperative ones are no more dirty than any of the others.