An overview of how Domestic house solar hot water systems work
Which pipes flow where.
Chromagen Rheem

After a comment below I looked up some other tankless/instantaneous heaters.
Thanks for the post. I had a look at your installation and these are a great idea.
I looked up some links for people to buy these here, they are not that expensive.
Rheem Electric tankless instant hot water https://amzn.to/2DToHdM

Rheem Indoor natural Gas tankless https://amzn.to/2DUeApg

Great Rheem Electric Tankless/Instantaneous https://amzn.to/2znABsv