Last month I purchased a Harman P68. I have really started using the stove heavily the last 2 weeks - mostly over night. I have noticed that when I run the stove over night that I am getting large clumps of ash developing on each side of the burn pot. The clumps are about half the side of my fist. Is this normal? Should I be running the stove differently? I'm using Stove Chow Pellets purchased from Home Depot. Any advice would be greatly appreciated.