2 one way valves?

[Renron]

I am building a solar heating system on my roof for my IGP ~18,000 G. Because the pool is the type with inground jets (sprinkler type) cleaners there is no sweep machine or pump outlet into the pool from the main filter pump. I cannot return the solar heated water to the same line because of the pressure is the same. It won't work. So........I have to run the solar heated water into a "feature" pump output line, (after the pump) this is NOT the filtered line from where the water is diverted to the solar panels.
Here's my questions;
I know I need a one way valve after the diverter valve on the solar panel supply side. I'd like to put a one way valve on the output side of the panels just before the "T" at the "feature" pump's output to pool side. The panel manufacturer says NOT to have 2 one way (check) valves in the system or it will void the warranty.
Any ideas why?
I do not want the "feature" pump to reverse pressurize the panels when it kicks on. I have no other means to return the panel flow to the pool. Dual end pressurizing would be disastrous! What am I missing with the dual one way valves?

Panels are 4x12 Swim Master Plus (5)
Thank you for your help,
Ron

 

[Bama Rambler]

Are you going to have a controller on the system? If so then hooking it back into the main return line is how I'd do it.
Adding a 3-way valve where the solar takes off will allow the system to work properly.

The way you have it shown, you'll pressurize the panels every time both pumps are on because the feature pump will close the check valve and not allow flow through the panels so the main pump will pressurize them to whatever pressure it's running at.

 

[mas985]

I know I need a one way valve after the diverter valve on the solar panel supply side.

Actually, you don't want to have the supply check valve in that location because that line will not drain. You should move that check valve to right after the filter and before the three way valve going to solar.

 

[Renron]

Thanks for the reply guys.

Bama;
No controller in the system, I am going to use a Jandy 3 way valve for regulation. Sorry for leaving out the information about the 3 way valve. I have purchased them already. Brain fart on my part.
If I hook it back up to the main line the higher pressure in the return line will prevent the lower pressure solar line from entering the flow back into the pool. That's why I have to run it into a different non pressurized line to the pool.

"The way you have it shown, you'll pressurize the panels every time both pumps are on because the feature pump will close the check valve and not allow flow through the panels so the main pump will pressurize them to whatever pressure it's running at."

Very true, I'll have to be careful to not program them to run at the same time while I have the 3 way valve open.
Question: If I open the valve only a small amount, would the pressure seen by the panels on the roof be lessened by the head height, ~15 feet to the bottom header, even if the panel discharge side was closed? (hypothetical)

Mas985,
You are so right, I don't know what I was thinking when I put it in there. Thank you. I'll place it just after the filter, reluctantly I'll need one on the panel output side before the T on the "feature" line to the pool.

Thank you both very much for your assistance. I really appreciate the knowledge I've and help I've received on this website.
I work at a medium size retail hardware store and constantly refer people to this website. I've had many return just to thank me.

Again,
Thanks,
Ron

 

[Bama Rambler]

The 3-way valve will alleviate the pressure equalization issue. It'll work fine hooked to the main returns.