So recently I've had an issue with black smoke from exhaust. Cleaned it thoroughly in an out a couple of times. Also my burnpot was a little more clogged than normal and pellets over feeding. So I decided to come out of premium mode and do regular mode. After 3 days my ash pan was full normally it would go 7 days. I mean this thing was overflowed. Ash in the firebox was far less and my ash was grey opposed to darker or black. In the ash pan were small black chips with the grey ash. Is that bad? Maybe I should try multi mode? Can anyone give me some advice?