I have a Franks Autotransformer purchased after a stressful trip to a DC campground in 2010. Embarrassingly I have never used it. I even wired up a nice plug-in setup in the rear compartment.
Never really needed it though as I also picked up a Kill-A-Watt meter and use it to keep tabs on incoming volts but that is also no guarantee that trouble is not looming.
I am concerned that (I read somewhere) it is NOT to be used with a resistive load which means NO ELECTRIC WATER HEATER. I don't know why it would make a difference as long as all loads are withing the design capacity. Not that propane is a problem but I don't want to "accidentally" turn it on to electric and blow up a $450 device.
Does anyone here use their electric water heater with an autoformer?