Originally Posted by herk7769
The thermistor is the thermostat. It varies the resistance of the circuit based on its temperature. At a pre-selected resistance the fridge turns on the heat. Sliding the thing up and down causes that resistance to be met sooner or later; thereby selecting the temperature to be maintained.
Think of a mercury switch in an old style thermostat. As the temperature rises the mercury expands and tilts the spring loaded glass vial over and closes contacts that route power to the heater or air conditioner. Sliding a lever adjusts the tilt one way or the other making that "topple" occur sooner or later.
That is the reasoning I said in my #19 post. I bet I am not the only reader here that didn't know what a thermistor was until reading here today.
The manual could show a picture of the thermistor in the section where it speaks about adjusting the temperature.
Some of these manuals you get - but that is another subject entirely (read my rand about the outdoor kitchen refrig thermostat location sometime and you will see what I am talking about).