Dirty Burn

My Stove is Burning Dirty.
My Stove is Sooting.
My Exhaust is Smoking Heavily.

Possible Causes

  1. Bad pellets, wet or old pellets, pellets which have been wet will not burn as clean or as hot.  Try using a different bag of pellets especially if the ones being used are old, from a torn bag, or may have been stored in a damp environment. It is important to have dry storage for pellet fuel.

  2. Improper installation, lack of outside air source or using too long a pipe to bring in air will cause air deficiency. Too long a flue pipe, or too many elbows, intake or exhaust can also lead to a dirty burn.  Air flow is very important to get proper performance improper installation can cause resistance to the flow of air, causing fuel to burn dirty. Refer to installation manual for proper installation to compare your installation to. Click Here for Diagrams and Instructions for proper installation

  3. Leaky gaskets, door, window, and ash pan gaskets, as well as gasket behind burn box will decrease available air through the fire. To test for leaking door, window or ash pan gaskets, turn the stove on without building a fire, close the door and take a lit match or lighter and move the flame around the edge of the window, around the door, and around the ash pan. If the gasket is leaking, the flame will be pulled toward the leak as air is sucked in past the gasket. Gasket should then be replaced. Click Here for Gasket Maintenance

  4. Overfeeding, if too much fuel is cycled into the burn chamber, there is insufficient air volume to give a complete, clean burn. A bag of pellets should normally last from 16 to 24 hours (smaller pellets tend to feed faster than longer ones) if the 40 lb. bag is not lasting that long contact customer service to have a technician walk you through a check of the programming of the control board.

  5. Insufficient combustion air, combustion blower is not running at sufficient speed. The exhaust blower should run at about 3000 rpm. Lubrication may help but replacement of the exhaust blower is the recommended course of action.

  6. Ash buildup in flue, if flue is not cleaned regularly ash buildup will restrict air volume being exhausted from stove. The flue system should be cleaned on a regular basis. We recommend it be cleaned at least once a month or once per ton of pellets used. Click Here for Cleaning Instructions

  7. Ash buildup in heat exchanger/firebox area, if firebox and heat exchanger are not cleaned regularly ash buildup will restrict airflow through the fire. The firebox must be cleaned on a regular basis and the holes in the firebox must be kept clear. The heat exchanger is accessed behind the baffle, and through the two access plates on either side of the burn pot cradle. These areas should be cleaned at least bi-weekly.

  8. Leaving hopper lid open/unlatched, when hopper is not sealed down tight air can be pulled through the hopper and feed system reducing the amount of air through the fire. It is extremely important that the hopper lid be latched down tight while the stove is in operation. Airflow may occur through the auger system and in the event of a power failure or error shutdown smoke can travel back into the hopper if the lid is not sealed down tight!

  9. Improper fuel, burning corn or cherry pits will cause a dirty burn because of the high ash, moisture and sugar content. The use of alternative fuel is possible when mixed with pellets but is not recommended. If the unit is burning dirty and these fuels have been used, clean the entire stove out thoroughly (flue system as well) and burn just premium hardwood pellets to see if the problem goes away. If using these fuels is still desired, adjust the mixture to use less corn or pits per bag of pellets.

  10. High altitude, air density at high altitude can cause dirty burn simply because of  the lack of available oxygen. In installations above 5,000 ft. above sea level the exhaust should be expanded to 4" pellet vent pipe (ac-3100 kit) and the outside air intake should be run with 3" pipe. Click Here for High Altitude Installations