I have seen a bit on this topic here already. Here is what is going on in my stove. Stove will be running fine, usually on level 1 or 2 (it rarely has to higher than that even though I'm in a 1870's farmhouse). I'll look over at the stove and see that suddenly the flame has gone and 2 and 3 are blinking, the stove has shut down but the convection fan still runs. Tube is not plugged and fire had been just fine with no lack of fuel (pellets) to burn. Restart stove, stove will run fine for anywhere from 2 hours to a full day before 2,3 repeating with shutdown. Convection fan still runs with no noise although I am going to get some bearings to keep on hand. Thermocouple still secure. When stove is on it gives great heat but I have yet to be watching it when the flame suddenly dies or fades away. Possible it could be an exhaust fan issue? Open to suggestions.