The Harman P61A Pellet Stove relies on state-of-the-art technology to automatically adjust itself to your desired room temperature. Simply pour your pellets into the convenient top-loading hopper and set the temperature dial on your P61A. If the room is much cooler than the set temperature, the P61A will produce a large fire in order to quickly reach the desired temperature. If only a slight increase is needed, the P61A will burn a small fire. This way, no energy is wasted by overshooting your predetermined temperature level. In addition to adjusting temperature levels, the P61A will automatically adjust itself for fuel quality. An ESP (Exhaust Sensing Probe) analyzes the output of the fuel being burned and adjusts the feed rate accordingly to increase fuel quality. The P61 models have the widest heating range of any pellet stove. The P61A can burn any brand of wood pellet regardless of the ash content. This allows you to buy lower cost pellets and achieve the same results for less.