My breckwell is a 1992 P24i that is burning well on the B level, which is the second setting. When I switch to C setting the firepot gets loaded up and chocked off from sufficient air. I have the feed rate variable resistor turned to the lowest possible rate. I burn Energex hardwood pellets which appear to be no longer than a half inch long. Is it possible too many pellets are filling the pot on C setting? Is there a way to check for a leak in the burn chamber? My airway is completly free of obstructions.