Originally Posted by Lothlorian
This is a relatively new fridge. I got it used. I am smelling ammonia and the coils are not rusted.
I hope you meant that you are NOT smelling ammonia!
If you are smelling ammonia, you have a serious problem. The ammonia leak is almost always in the area of the AC heater. You would not see the area of the leak unless you remove the "stovepipe" and insulation around the area of the heating element.
Propane does cool the box slightly faster than AC because it puts more BTUs into the system. In both modes, you should feel heat in the tubing above the boiler in a short time.