The feed setting controls how fast the auger is feeding fuel to the fire pot. If it is set too high you can actually end up wasting pellets because they will be pushed unburned into the ash pan. Where I live in the North East I keep my temperature set at around 73 degrees, the feed setting is set at 3, and the blower is mid range. This keeps my whole house warm. Occasionally I do use the fan to get some of the further away rooms a little warmer but this year I have not had to use it too often.