That's one of several postings on adding an inside switch for the water heater. If you do a search for "water heater switch" you will find the others. The main panel on our unit had a blank space next to the propane heater switch so I installed a lighted switch and wired it to the 120v electric side of the heater. It was rather simple since the switch panel is about 3' above the power distribution panel with the circuit breakers.
Rather simple mod. Simply add lighted switch next to panel and move your service that feeds your hot water heater receptacle from the breaker and move to the switch. Add your hot and ground from the switch to the panel.
One other option- IF your water heater is on a circuit breaker by itself-
you can just flip the breaker when you want it off.
Some units have the WH on it's own breaker and some have it tied in
with something else, like the fridge.
Mine is on a stand alone circuit so I use the circuit breaker.
My outside "hidden" electric switch is frozen in the on position but I don't
__________________ Peace! Dan & Rita D
2004 5.3L Silverado 1500 ext. cab 2WD
1999 Suzuki Intruder Motorcycle
Blue Ox WD hitch, AirLift load levelers
Camping days 2010-53, 2011-47, 2012-41,
2013-41, 2014-31, 2015-40, 2016-38