I came to my bus yesterday to find no hot water.
today, i had a bit of time to investigate the problem and frankly i'm stoked that it wasn't worse.
i had installed a relay that i could switch the hot water heater on and off. i left the relay actuated for a number of days while plugged into 50 amp service.
it looks like it got hot and burnt a few wires. the fire was under my bed, and even left a soot stain on the bottom of my mattress. i never knew.