When it is under heat, it causes the amonia mixture to rise from the bottom vessel(round tank) to the top of the tubing grid. When not under heat from (propane, electric element) the mixture returns to the round vessel. After it settles, put it under propane as the heat source (set button to gas only). I say that because you are running a 50ft.12/2 extension, and you can't be sure your gettiing enough current to the electric heating element, for sufficient heating of the amonia mixture and thus the cooling result. You will however, under propane heat. But, plug in your RV, so the piezo ignitor drawing current, does not run your batts down.