Simple solar batch heater on a river boat tiny home

DIY Solar batch type heater advice needed .

Hi all , I could use some advice about installing / plumbing in a batch type heater to my little Floating tiny home

The goal here is to construct a simple batch type heater on the roof of the little boat and heat the water during the day.

I would like to drain this water back into an insulated tank , then pump it through to my shower using my 12 volt dc pump.

I am building an experimental heater made of PVC pipe to try out some of the possibilities .





The issue I have with this is , I am worried about potential pressure build up in the batch heater , so my thoughts are to only partially fill the batch tank to allow the water to expand inside the tank as needed .

How could I then mix the water with cold to temper the water so I don`t scald myself ?

The other way is to use batch heater as a pre- heater for a small electric hot water tank when connected to mains power.

This part is the difficulty , because I can only see this part of the system as a closed , pressurized one ?

I hope I have asked the right questions the right way.

A simple schematic diagram would be useful.

Bear in mind the Legionnaires issue with storage of hot shower water. That's something you're going to want to nail down.

Kyrt Ryder wrote:Bear in mind the Legionnaires issue with storage of hot shower water. That's something you're going to want to nail down.

Yes indeed.

Ideally , for a first set up I would like to use the solar water heater as a pre- heater for the electric water heater.

I think the energy savings could be significant , while still having the water at a safe temperature ( hot enough ) to eliminate Legionairs.

Any thoughts on this ?