Last night when I turned it on, it was running fine. This morning when I went to turn it off, the fan and motor wouldn't stop running. I had to unplug the unit in order to stop it from running at all. Now, when I plug it in, and the knob is in the "off" position, the motor and fan starts to run. Could it be the that the condenser coils need to be cleaned, or that it's just dying on me? Please let me know as soon as possible. Thanks.