Almost all Pellet Stoves and/or Grills require motors, fans, blowers, electronic controls, etc. in order to function correctly. Most manufacturers of Pellet Stoves and/or Grills rely on outside manufacturing suppliers that specialize in manufacturing these components.  A couple of examples:  -Ford™ does not manufacture the tires for the vehicles that it sells.  Toyota™ does not manufacture the air bags used in the production of it’s vehicles.  Both rely upon outside manufacturers for the supply of these parts.  These component subcontractor manufacturers are considered OEM manufacturers. Ford™ and Toyota™ would only be the OEM manufacturer for the vehicle parts that they actually manufacturer, such as fenders, body panels, etc.  

It has long been a common misconception that only a factory authorized dealership that sells the original Pellet Stove and/or Grill carries OEM parts. Though they would like you to believe that, it is not the case.  Many component parts that you get from a factory authorized dealership can also be obtained elsewhere for less money, and are made by the exact same company(s) that makes them for Pellet Stove and/or Grill Manufacturer. Keep in mind that there may be more than one component manufacturer for the same part. 

When buying parts, the term OEM does not mean that the part is better. It only means "the same as".  Many aftermarket parts (parts that are not made by the same outside manufacturing supplier) are as good as, and in some cases better than the original part. Keep in mind that there are very few low quality manufacturers of parts.  Those that do exist, typically will NOT be in business for very long.  Also bear in mind that there is most certainly some aftermarket parts that are significantly better that others.