Pellet Stove Burn Pot Overflowing [7 Easy Solutions]

Pellet stove burn pot overflowing mainly due to the fire getting insufficient airflow, the stove’s dirty internal components, using poor quality pellets, and ash build up.

Also, the stove’s incorrect settings, defective ash pan gasket, and unburned or partially burned pellet accumulation are responsible for it.

However, going through our guide, you can fix your pellet stove burn pot’s overflowing issue by yourself. So, let’s get started…

Pellet Stove Burn Pot Overflowing [7 Easy Solutions]

After burning the stove for a few hours in high or medium settings, your burn pot overflows, and it’s pretty annoying. The following factors are responsible for this problem, and their solutions are the followings.

1. Fire is Not Getting Sufficient Airflow

Are you thinking, ”why is my pellet stove burn pot overflowing?” Don’t think much. Your pellet stove’s burn pot is overflowing because the fire is not getting adequate airflow. 

The pellet fails to burn correctly due to insufficient oxygen in the furnace. Poor airflow slowed down the stove’s burning. As a result, the burn pot overflows. The causes of it are:

  • Blocked air inlet in the burn pot
  • Lower burning
  • Faulty or leaky seals
  • Air-to-pellet ratio imbalance


So before thinking much about “why does my pellet stove burn pot overflow?” First, ensure that the fire gets sufficient airflow.

And nothing is creating the airflow blockage. Ensure adequate oxygen supply in the stove, so that the pellet can burn perfectly. The other general fixing ways are:

  • Clean the burn pot’s holes and remove the air inlet’s blockage
  • Ensure the pellet’s proper burning
  • Repair the leaky seal in the burn pot and replace the faulty seal
  • Make sure the appropriate balance between the air-to-pellet ratio

2. Dirty Pellet Stove and Internal Components

The filthy internal components of your pellet stove are responsible for your stove’s burn pot overflowing.

The dirty firebox, exhaust system’s fan blades, air intake filter, vent screens, and vent dampers cause the overflows of your burn pot. Also, the dirty pellet stove itself is responsible for this trouble.

Dirt, debris, and foreign objects build up within your pellet stove, or its components hindering the unit’s smooth running. Also, not cleaning the stove frequently causes dirt build-up. As a result, the burn pot overflows with pellets.


Following the manufacturer’s recommendations, clean your pellet stove and its internal components daily, weekly, monthly, or seasonally. Thorough cleaning of the pellet stove’s units is the prime solution to this issue.

Properly clean the firebox, exhaust system’s fan blades, air intake filter, vent screens, vent dampers, and the burn pot. Ensure the dirt build-up is not hindering the burn pot’s easy operating process.

Note: How to clean a pellet stove burn pot and how often to clean a burnt pot pellet stove, you will get all these instructions in the stove’s manual.

3. Using Low-Quality Pellets

Using poor or low-quality pellets for burning in the stove is one of the main reasons for which your pellet stove’s burn pot overflows.

The low-quality pellets struggle to burn correctly and efficiently. The main factors accountable for degrading pellets quality are:

  • Pellets contain too much moisture or wet pellets
  • Improper seasoning of pellets
  • Poor handling and maintaining the pellets
  • Incorrect storing of pellets


Use high-quality pellets in the stove to ensure consistent burning. The other solutions are:

  • Make sure the pellets are not wet 
  • Use properly seasoned pellets
  • Store pellets properly in an arid and cool place
  • Properly handle and maintain the pellets

4. Ash Build Up

The firepot’s holes blow sufficient air into the stove’s fire. The excessive ash builds up in the firepot blocks these holes and hinders the air blowing.

As a result, the pellet in your stove just keeps dumping, and the burn pot overflows. The noteworthy causes of it are:

  • Burning wet pellets
  • Poor draft
  • Inadequate oxygen supply
  • Incorrect air-to-pellet ratio adjustment
  • Not cleaning the stove for a long time or leaving the ash in the furnace for a prolonged period


Properly clean your stove’s firebox or heat exchanger area to prevent excessive ash build-up. The other fixing ways are:

  • Use a properly dry and well-seasoned pellet for burning
  • Ensure proper draft and adequate airflow in the stove
  • Correctly adjust the air-to-pellet ratio
  • Don’t leave the ash in the stove’s burn pot for a long time
  • Properly clean the furnace and burn the pot frequently

5. Incorrect Stove Setting

If your stove setting is incorrect and your stove fails to get adequate combustion air, then the burn pot could overflow.

Due to improper setting, the furnace fails to adjust the air combustion, and the pellets in the stove overflow.


Turned down the blower trim to a half turn to adjust the stove’s setting or combustion air. Properly adjust the stove’s air combustion to prevent the fire pot’s overflowing.

6. Accumulation of Partially Burned or Unburned Pellets

Constant accumulation of unburned or partially burned pellets in the stove causes the burn pot’s overflowing. The main factors responsible for it are:

  • Using the wet or unseasoned pellet
  • Using excessive pellets constantly than the stove’s capacity
  • Not cleaning the burn pot or stove for a prolonged time


The stove can’t burn the pellets properly due to too many half-burned or unburned pellets accumulation. Solve this problem following the ways below:

  • Use high-quality dry and properly seasoned pellet so that it burns perfectly
  • Don’t use pellets constantly in excessive numbers
  • check whether there are unburned pellets on the stove or not, and frequently clean the pellet stove

7. Faulty Ash Pan Gasket

Ashpan latch stops the air from leaking and ensures the draft required for a perfect fire. Without a latch, an ash pan gasket fails to compress enough air.

Also, the defective ash pan door gasket fails to make a tight seal. As a result, the burn pot overflows with pellets.


Ensure that your stove’s ash pan gaskets are good. Also, make sure that the unit is properly sealed with the ash pan latch. Replace the malfunctioning ash pan gasket if necessary.


Why does my pellet stove keep backing up?

Your pellet stove keeps backing up mainly because the pellets are not getting enough air to burn, lack of pellets in the stove, dirty venting, and the stove. Also, the wearing out or weak exhaust blower and dirty air intake filter are responsible for it.

How do I know if my pellet stove is leaking?

If there is any leak in your pellet stove, you will see the soot or dirt build up around that leak. If there is no dirt build-up, you can check the leak another way. At night flash a bright light through your stove. The flashlight will shine through the stove’s leak or holes.

Why is my pellet stove burning so many pellets?

Your pellet stove is burning or feeding too many pellets due to the feed rate’s incorrect setup, blocked or dirty stove, air combustion issue, pellet’s poor combustion, or insufficient air supply.

Why is my pellet stove smoking out of the exhaust?

Combustion air adjustment, sooty or overactive flame, insufficient air supply, and dark smoke coming out of the stove’s vent are mainly responsible for why your pellet stove smoking out of the exhaust.


Hopefully, after reading the above instructions, you have a clear idea of why your pellet stove burns pot overflowing. You now know both the causes and solutions to this issue.

So, if you face such a problem, fix it yourself by following the above-mentioned solutions. If you have any other queries, you can comment. We’ll answer your queries ASAP.

Note: You can also read how to fix Castle serenity pellet stove problems.

About William

William is the founder of He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

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