Stop in for a cup of coffee

Morning. 3:11 dog wants out.
Check pellet stove. Low flame and burn pot is overflowing.
Great. Two stoves by same manufacturer and one doesent have any problems. Guess i will swap burn pots and see if thats the issue. Im thinking the airflow
Is the issue here. The shop heater has 15 feet of pipe and this one has 8. Could be dirty.had a wind from the south,would have slowed the burn.