Steve,
Found the problem with the electric and it is working. Because I could hear things running, it never occurred to me to find the breakers (which are not where I expected) and the heater had tripped. Once I reset the breaker and let the electric run for about two hours, it was working when I went in and checked, both heat and water.
I have turned the electric off and the diesel on and will see what happens. Be nice if the tripped breaker was the problem all along, will update in an hour or so. Thanks to all the people who contributed ideas, it really helps to have support, and I think I learned a little bit about the aqua-hot along the way!