Originally Posted by paulwadley
Your coach furnace runs off of 120v either shoreline power or generator power. If you are running the plug in portable electric heaters it is the same situations with power. If you are using a heat sump from your roof air you need either shoreline power of generator power for it.
The furnace is 12V and will run with no generator or shore power. It will run your batteries down over time so keep an eye on your charge level. In most cases, overnight use of your furnace will not deplete batteries unless it's "tundra cold" and the furnace runs all night.