For those who do a lot of boondocking, they may rarely to never use the electric heating element of their water heater.
As a newbie to trailers a few short years ago, once I got that cotter pin out of the rocker switch, switched it on and hit the button inside the trailer, I instantly fried the element. Bad news was not the $15 to replace it.
After staying in a state CG that used GFCI breakers in their service boxes and continually popping their breaker, I spent hours at home with a VOM, tearing the converter and AC circuits apart before I isolated the issue to the water heater circuit.
Long story short, if the water heater tank is not flooded with water first, you will fry the electric heating element and not realize it right away.
That all said and fast-forward a few years, I love and nearly always heat the water using the element. If it's built into the rental fee of my CG site, I'm cookin' water with electricity!
As an aside, this rocker switch on the water heater was off when I went to de-winterize this spring. I think the shop that did the winterization must have switched it off. Anyway, it was super-hard to switch to the on position. I mean, I used the end of a tool and a lot of force to get that thing to snap to the on position. Not sure if I was fighting against a safety mechanism with brute force and ignorance or if it was just stuck.
Jim
(missing camping.....)