In my addition of the switch in the foto, there was not one bit of additional wire used.  They wire Pods so sloppily that I had plenty.  I used the following materials that I had laying around the house:  1 shallow plastic switch box (cost 39¢), switch (69¢), switch plate (28¢), 2" plumber's tape (<1¢), 4 screws (<1¢), and a small block of reclaimed wood from when I ripped out the top bunk (free). Labor about 15 minutes as a retrofit.  Total cost in materials $1.38 (retail).  Labor using my usual and customary lawyer billing rate  ... it depends.

I should add:  All the stuff I used for this switch was repurposed from junk I had laying around the garage, well, not really laying around but carefully stored away.    The total cost of this very functional modification was under $2.00.

The switch on your galley panel only controls the operation of the gas option for your water heater.  Turn it on and you're running on gas.  It is not connected to the electric heating element.  It is your choice whether to use gas or electricity to heat your water when you are plugged into 30A plug at an RV park or where ever.  Personally, I think it makes more sense to heat with the electric element when  you are at an RV park because you already paid for the electricity in your park fee.

There are two switches that control electricity to the electric function of the water heater.  One switch is elegantly demonstrated in Marwayne's foto.  There is a second switch that is not obvious to the new user.  In your circuit breaker panel one 15 A breaker controls electricity to the water heater.  That is your inside "switch."  Some people are not comfortable using a circuit breaker as a switch, but that breaker is rated to work as a switch.  

The outside water heater switch, as depicted in Marwayne's foto, is a pain in the pelvis to use and is easy to forget to turn off.  It's a little hard to reach and opening and closing the water heater door is a hassle, especially if you have a little arthritis in your fingers.  Leaving it on and using the breaker/switch to control the water heater is another option, but it has its drawbacks as well.  If someone else uses your Pod and is not familiar with the "correct" off position for the breaker, s/he could turn it on without realizing s/he's energizing the heating element.  It's easily overlooked when all the breakers are in the on position.  So, you need to be very careful that no one inadvertently flips the water heater breaker to the on position.

There is a third option available.  You can add a switch by your water heater to control current to the unit.  This can be done in the romex cable that supplies power from the WFCO circuit panel to the water heater or it can be wired separately from the water heater switch on the outside.  Personally, I think adding the switch in the romex line is easier and it's what I did.  It took about 15 minutes to install a third water heater switch that is easily accessible and eliminates the confusion problems.  I added a little cover over the switch lever with a piece of plumbers tape [that metal tape with holes in it]] so the switch wouldn't get accidentally tripped.

None of this is adequately explained in the user's manual.  I have no idea why.  All I can say is that Warren Buffet is a lot smarter than I am and I suppose he had his reasons for not putting clear instructions in the r-Pod user's manual.  In my more cynical thoughts, I wonder whether another one of his companies makes water heater elements, but who knows?

Read that the hot water switch you point to has to be on as well as the one inside on the control panel (assuming you’re plugged in) - right? Can you leave that switch you point to on all the time and control with the inside switch? Two switches are confusing. 

Anode rod

electric switch

reset buttons

pressure relief valve

Thanks! Sure is great to be part of this group! Hope to see you on the road.