Installing Solar Diverter Valve

stoteda

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Jun 15, 2020
15
California
I recently installed a complete Pentair System, EasyTouch controller, VS Pump, and IC40.

I am now ready to add the diverter valve to a roof mounted solar. I saw a picture in one of the posts that show a single diverter valve and a check valve, plus vacuum break at the top of the solar plumbing.
I want to have the system go on automatically when the solar is hot enough.
I assume I need a 3 way diverter with a pentair valve controller.


Is there a best practice for this?
 

hwy17

Well-known member
Mar 17, 2021
190
Northern California
Do you have an existing solar system or is this all from scratch?

Florida Solar Design Group standard makes sense to me. Some use dual two way isolator valves but I agree with their logic that it's not necessary.

You can use a 3-way with a hole drilled in it, a 3-way and not completely close it for bypass mode, or ideally the specific Pentair 3-way solar isolator valve which has a tiny check valve in the blocker plate.

The main thing to wrap your head around is that the 3 way diverter needs to allow drain down from the supply pipe to the pool return when the pump is off.

 

stoteda

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Jun 15, 2020
15
California
I was looking to keep things simple, and did not think I need the isolator valve, but I do have the check valve and vacuum break to allow the drain down.

Also, I plan to run the solar heating in line with the pump and before the sand filter. I've looked at the link to the Florida Design, and found it helpful, but it did not show the full system. I've attached an overall plumbing diagram I plan to use to guide my project.

The Pentair 3-way valve does not seem to be easily found in stock, so I've been looking online for this part. I was wondering if I can replace the diverter assembly from the Pentair 263028 with the diverter assembly from the Pentair 263047. If so, I can plumb everything this weekend and order the diverter later.

1618533578128.png
 

hwy17

Well-known member
Mar 17, 2021
190
Northern California
You can definitely get simpler than the best practice. Mine is just an H with a two way valve in the bypass, the horizontal line. I rely on the built in check valve in my filter to prevent back flow.

The main problem with your plan there is unfiltered water to the panels. That is not advisable with any commercial panels, the channels can clog up with dirt and the pressure in the panel will be greatly increased.

I'm pretty sure you can replace the diverter in that three way with the solar drain down one, or you can just drill a hole in the diverter plate, or make sure to never fully close it.
 
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stoteda

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Jun 15, 2020
15
California
Once again TFP has saved our pool ; )

Great point on the unfiltered water, I will modify the design to move the solar intake to the filtered side, and out of caution, add a check valve below the diverter valve so the drain down flows out to the pool side and not back into the filter (which is what I was trying to avoid initially). So, this brings me to the original design you suggested without the one shutoff valve...thanks!
 
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stoteda

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Jun 15, 2020
15
California
Here is the modified plumbing diagram after taking your feedback into account. I also moved the intake to the Polaris pool sweeper to a point after the filter as well for the same reasons.

1618545542532.png
 
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