We leave ours on electric (switch under the water heater cover outside). When I use the shower or a lot of hot water for dishes or whatever, I'll turn on the propane (inside switch). It recovers quicker and allows you to use the shower longer than the 2 minute navy shower.
Turn it off when you're done (switch on the control panel inside) and the electric will maintain it. You don't have to turn the outside switch off.
Mark, Vicki, & Scout THE dog
2015 Hemisphere 282RK
2010 F250 Super Duty
1992 Goldwing Aspencade