I have a 3 year old Harmon 52i. intermittently (although more frequently of late) the stove will come on and fill the burn pan with pellets to the point of near overflow. There is no ignition and the stove shuts down, as it is supposed to do. I do have an ignition light during this process. I cleaned the burn pan, turned the stove off then back on again same results. I turned the stove off cleaned the pan again. I accessed the ignitor and it felt warm I closed it up and turned the stove back on. this time it lit, although the flame started from the left side of pan and not from the middle. as the flame worked its way across the pan the stove continued to feed pellets, pushing unburned pellets from the right into the ash pan, I noticed this on several occasions of late. I cleaned the holes in the burn pan last week so I don't think that would be the problem.