Not offgrid, but I use propane for stove, hearing, and water heating. For stove I needed an adapter. I think for the water heater too (either that or the model I bought was propane ready). I didn't install it professionals did. I'd say call a professional.
Discussion
I might wind up having to do that... I did convert the dryer to propane, but the water heater is specifically sold as a propane water heater.