Check the reading on the barometric damper on your coal stove's flue. The opening should be between 0.04 inches and 0.08 inches.
Turn the knob on the barometric damper clockwise to increase the amount of airflow into the coal stove. Turn the knob counter clockwise to decrease the amount of airflow into the stove.
Examine your fire in the coal stove. There should be no smoke coming back into the stove from the flue and the fire should be burning evenly. Check the temperature to make sure it’s between 350 and 450 degrees Fahrenheit in the stove.