Pellet stove pellets piling up: Why, and how to fix.

Pellet stoves are a very efficient form of biomass stove. Their efficient operation is achieved by burning a controlled but small amount of biomass pellets at a time. The flame (and therefore the heat provided) is a function of how many pellets are being burnt at any one time, and how much air is drawn into the stove.

If there is a change in the number of pellets fed into the burn pot, or in the airflow, the heat provided by the stove will be affected.

Therefore, if there is some sort of failure in the feed rate of the pellets or the airflow this will reduce the efficiency of the pellet stove. The outcome of this may be too many pellets are being used, or the stove is either too hot or too cold. In essence the pellet stoves become inefficient.

This article will focus on the problem of pellet stove pellets piling up, the causes and solutions.

Causes of pellets piling up

Clogged burn pot

A clogged (too much ash) burn pot or ash pan can be a major contributor to pellet stove pellets piling up.

The ash and debris that accumulates in the burn pot or ash pan can interfere with the proper airflow that fuels the flames, reducing the effectiveness of the combustion process. The pellet stove may overcompensate by feeding more pellets that are not able to be burned properly, this could lead to choking the flames and / or causing a bigger than expected flame due to excess fuel. Regular removing burnt ash from the burn pot and ash pan is an important part of maintaining your pellet stove to avoid this issue.

Faulty Auger

A faulty auger can be a significant cause of pellet stove pellets piling up.

The auger is responsible for transporting the pellets from the hopper to the burn pot in a controlled manner. If the auger is damaged, worn, or not functioning properly, it can cause the . This can result in too many pellets being fed by the augur into the burn pot.

When the hopper is empty and the pellet stoves has had time to cool, this is a good time to check the auger.

  • Make sure power is removed from the pellet stove before touching the auger.
  • Start by visually inspecting the auger, making sure there are no obvious signs of damage.
  • Next try wiggling the auger from side to side. It should not move very much, if at all.
  • If you suspect the auger is damaged we recommend calling a professional to inspect are repair.

Inadequate air flow

An inadequate airflow can be another cause of pellet stove pellets piling up, and in our experience the most likely cause.

The draft is the flow of air into the stove that is necessary for the combustion process to take place. If there is insufficient airflow, the pellets may not burn as quickly as they should. Then when the pellet stove adds more pellets it chokes the fire, and you will see a buildup of excess pellets. Choking the fire causes more smoke.

Regular cleaning of the entire air flow path is necessary. Make sure the flue does not become clogged, as clogging the exhaust is a common reason for reduced airflow in all types of wood burning stoves.

Additionally make sure the blower is working. The blowers job is to fan the flames, it the blower is not providing enough air it is taking away one of the most important ingredients needed to maintain a fire, oxygen. A faulty blower is perhaps the most common cause of an inefficient pellet stove.

Make sure any air vents are not clogged with ash. A regular clean out of ash is recommended. When cleaning ash take a few seconds to make sure ash is not floating around the combustion chamber and getting lodged in the air intake ducts.

Lastly, and this may sound obvious, but we have seen it. If you are using an external air vent, make sure it has not been capped.