Thank "sprint2freedom" on this site. Did not know what a Sous Vide machine was until he said that was what he used to heat shower water. Googled it and sure enough in my opinion he had discovered the simple solution for a van shower. So I spent some time trying to optimize the idea.Brilliant Dave. And oddly enough, I was just thinking how I hadn't used my Anova Sous-Vide machine since the early Spring — after getting an email pitch from Anova.
Today I ordered a battery and parts to make a portable 12 volt power pack so the system could be used anywhere. We live in Ca. where there are fires. Expect next fire season to have PGE regularly turn off the power so they do not get sued for starting the fire. We can use the portable shower water heater in the house to shower. Heat the water in the van and carry it into the house and power the pump with the portable power pack.