You need to first start a roast in an "automatic" mode, then hit the buttons P1 to P5 to change the burner setting. Now you are in Manual Roast mode, and can change the Burner setting manually at any time, you can change the Drum Motor Speed to High (32 RPM) or Low (16 RPM) by hitting the "D" Key... and you can return to Automatic mode by hitting the "1" Pound roast key