A trip away with Dutchdude (Rob) and his solar water heating system got us thinking.
We had 3 quick showers out of twenty litres. Let's be honest it's a quick freshen up shower but really that's all thats needed.
The first problem was our weather doesn't get hot enough to rely on solar heating which got me thinking and a trip to my favourite place and return home without a normal heat exchanger but this..

Dug out a 12v water pump (purchased last year solely for the job.

The idea was to plumb it into the van's coolant system somewhere take a water feed from the external tanks. But the calorifier had 12mm outlet inlet so played around with them to get them to 15mm to fit the coolant pipes, bit of solder/ copper tube and job was a god 'un.

This its new home

And now in with drain off valve fitted to prevent winter freezing.

Episode 2 later