water heater won't run on electric

Lots of good info here for you, hope you get it straightened out. Just for comic relief, I will tell you about when I had a similar problem last year. It worked fine on propane, but had stopped working on electric. I checked everything ( I thought) but wasn't till I was draining everything for storage that I saw a switch inside the outside cover that I had forgotten about ( was our first summer with this rig). Sure enough, with the switch turned on, the water heater worked just fine. I vaguely remembered turning it off when I was flushing the water system after we had bought it. Good luck and hope it's not a serious issue.