Thanks for the help
I have added some labeling which I think is correct. (please correct as needed)
I think I'm beginning to understand but there is a "solar loop" that has me baffled. Water from the roof panels feed along the bottom and up through V6. Then to a "T", one port to a pipe going down to the gas heater and the other port to V5. V5 is as you said, a motorized diverter valve for solar. It is automatically controlled by a Aquastar II Solar Controller. (if it's functioning properly)
The output of the gas heater goes to V4 which controls the hot water split between pool and spa.
I have adjusted V1 to control the flow of the vacuum to keep it from tangling.
The solar system has sensors, I think one on the roof. (there is a wire from V5 that leads to the roof) Also a wire shown in first pic (bottom center) that goes straight into the concrete next to one of the return pipes. ??
How, why and when does the "solar loop" work? Does it work without the gas heater being on? What should I look for when pressing "Test" ?
There is a solid non-insulated wire that goes from the pump to the heater. ??
What is the purpose of V3 and V6? When and why would I adjust them?
Thanks again ...
Curt