Pool Heating Array - Correct?

[markpj23]

New to us house has 10 solar pool heater panels on the roof as shown in the drawing. They all have to come down so the new roof can go on. No better time than now to correct any errors in the system. I already know that there are no back flow preventers in the supply riser so I plan to add one. I also noticed that there is no air admittance valve / vacuum break at the high point of the system. I assume it should have one? Panels are 3 above 7 to fit within the shape of the roof.
Any comments / tips would be appreciated.

 

[OzSolar]

New to us house has 10 solar pool heater panels on the roof as shown in the drawing. They all have to come down so the new roof can go on. No better time than now to correct any errors in the system. I already know that there are no back flow preventers in the supply riser so I plan to add one. I also noticed that there is no air admittance valve / vacuum break at the high point of the system. I assume it should have one? Panels are 3 above 7 to fit within the shape of the roof.View attachment 145477
Any comments / tips would be appreciated.

Congrats on a new to you house! It's likely a drain down system. Pump shuts off and water drains back into the pool. No need for a backflow preventer or an air bleeding valve. (not an air admittance unless you're talking about your domestic waste system )