The Pellet Pro System makes it possible to burn any grade of pellet fuel for maximum heat and efficiency. This patented bottom up feed system truly offers 24 hour heating it does not need to be turned off to perform basic maintenance and regulates heat within one degree of your set temperature. The motor drives the auger, while the auger is turning, the cam system lifts the pusher arm which opens the slide plate to allow more fuel to drop . The shape of the burn pot grate, along with the number and placement of air holes keeps the burning fuel contained and directs the movement of heated air to the heat exchanger. Harman's Pellet Pro System helps deliver warmth and comfort, while saving time, money and hassle.