Dirty Door Glass

The glass window of your pellet stove can provide more than just a beautiful fire. Knowing the type of build up and the rate at which the glass gets dirty are indicators of how the stove is running. The color of the build up indicates the use of the stove. More importantly the color of the build up can be used as an efficiency indicator.

Above we have two images from the same stove, a one month old Mt. Vernon AE insert. After one mildly warm week from previously cleaning the glass, we find a white powdery ash. It is possible to find this much build up after only a few days during the colder parts of winter. As the stove runs more, the glass will get dirtier. Notice the white color. Although a picture will not depict the texture well, it is also a factor in the stoves efficiency. A proper Air-to-Fuel ratio produces the white ashy build up.  

Two separate stoves are pictured above. Although we do not know how long it has been since the glass was last cleaned we can tell that the stove is not running efficiently. The dark and sooty build up is the result of a lack of air flow. 

Poor air flow is most commonly caused by a dirty stove. The first step to troubleshooting this issue to conduct a full cleaning. If you do not have a professional do the cleaning, refer to the owner's manual. Although you may think you have cleaned everything, there might be an area you overlooked or did not know about.

In rarer cases, a vacuum gauge  may be required to find where an issue is within the stove. If an airway is completely blocked, your stove will do everything except drop pellets. On a MT Vernon AE you will receive either an "Auger Jam" or "Vacuum Switch" Error