Thanks Jeff.
I most definitely need a second tank that will act as a pre-heater. I drew out a diagram of what I would need and then came across the image below which looks really similar to what I had envisioned. I would be using vacuum tubes to heat water though.
1. No potable water enters the vacuum tubes. The tubes simply heat up the water in a header of sorts.
2. I have a circulating pump with a built in timer already. So I could set it to circulate the water every hour for a few minutes during daylight hours. My pump would be just as the one pictured in the image.
3. I would be looking into getting a used or cheap hot water tank and using it for a pre-heater. I'm assuming I could utilize the check valve and drain valve as my 3rd and 4th water outlets?
4. I have an expansion tank on the cold side already. Would I have to install a second expansion tank and I assume I would need to re-install the check on the holding tank somehow or in the pipe?
Thanks,
Ralph