Way too inefficient to use inverter. Water heater element about 11 amp draw AC means 110 amp draw plus loss do to inverter inefficiency. Heck of am amp draw off batteries. Again rough estimates, element sizes can vary.
Industry rule of thumb: inverters are not used to power things that heat or cool I.e. water heaters or AC for example.
Your has water heater is set to heat water much warmer than your water heater at home, usually 140 degrees so you can mix a good bit of cold water otherwise it will scald the crap out of you.
Steve and Andra
2012 F350 6.2 gasser SRW LB
Fab Fours front and rear in case we run into a rhino
2019 Northstar Laredo SC