I never had the instructions. That is my problem. I have the fan/heater/humidifier as a 'hand me down' gift and I want to know how to use it. It has two knobs you can set. One obviously sets a room temperature using a scale from 0 to 10. The other knob has four positions: off, on fan, a half filled circle and finally, a filled circle. I want to know what the two circles signify. One page of the instructions should cover that. I can remember what settings are for. Thanx in advance.