Not to confuse you with the draft blower. It is pictured below, just south of the main door. Its function is to kick in when a thermostat falls below a desired temperature in the main living area. It will get the fire roaring again until the home is heated to the desired temp once again, and again the thermostat will than shut the fan off. Just like a regular furnace operates. But I feel the blower gets the unit way too hot, so I dont use it. But I do have it rigged to where I can simply turn the fan switch on manually. Which I do use when getting a new fire up and running.