Don't think there are any elect tank heaters, but that is a guess. If you don' have a switch in the control panel then it is a definite no. I can say that we've been out in 17 degree weather and our MH does not have all the extra insulation and nothing froze and I was not using the furnace just elec space heaters so no warm air was blowing into the utility compartment. You can run the furnace while traveling, your tow vehicle will supply enough charge to keep the batteries up, you don"t need shore power.
And I'm glad to hear it works we just ordered a new PINNACLE.
PINNACLE 2015 38FLSA. aka: "Roam Sweet Home"