why does my pit boss PB1000PL smoker begin to smoke into the pellet box after 5 hours of smoking. I clean the unit after every cook

[buzzer1949]

why does my pit boss PB1000PL smoker begin to smoke into the pellet box after 5 hours of smoking. I clean the unit after every cook so the burn pot is not full when starting.

 

[Cowboy1955]

why does my pit boss PB1000PL smoker begin to smoke into the pellet box after 5 hours of smoking. I clean the unit after every cook so the burn pot is not full when starting.

Have you sifted the pellets through a colander?
I use bear mountain pellets because that’s the only brand I’ve found without a lot of dust