I have a St Croix Hastings stove that has started to produce a flame on lower settings that sends the flames towards the rear of the burn pot and up towards the auger and drop chute? I have owned and maintained the stove for the 15 years and can't figure out what is going on. I have thoroughly cleaned the unit and fans, replaced all of the gaskets and also a new burn pot, and checked the versa grate to burn pot clearance. Tried adjusting the damper with no improvement. Tried adjusting the draft trim voltage, no improvement. The stove has a good flame on the higher settings, only an issue on lower settings. My fear is a fire starting in the auger and then up into the hopper. Any help would be appreciated.