I'm new to pellet stove. I just picked up a used Englander 25-PDVC. I installed this in my basement, I run it at 6,6 it seem to be burning a lot of fuel in 5 hours. I only use it when I'm home after work. I would like to know what's the best setting that's everyone using for the best efficiency. The 3 buttons at the bottom do you keep it at factory setting or do you have your own setting.