Questioning my Setup - No Check valve on Solar Apparently


Well-known member
Oct 20, 2015
Huntington, NY
Over the winter i had some branch fall and damage some of my plumbing. I have a 3 way valve for my solar. The pipe that leads to the solar from this valve was cracked along with the elbow and the valve itself. I ordered a replacement valve and was lining things up and making a list of parts to buy to swap in, when suddenly i realized, there is no check valve at all. Essentially, the way its plumbed, when my solar is "off" and the right side (top in the picture) of the valve is closed, water is being pumped up the return from my solar backwards up to my roof, through my panels, and then back down the and then getting blocked by the valve that is supposed to be stopping the water from being pumped the normal way up the panels. So yes, it prevents the water from actually reaching my pool, but basically whenever my pool pump is running and the solar is off, water is being pumped on my roof, pressurizing the panels, and it is sitting there constantly as long as the pump is on. i had these panels installed in 2017, so basically it has been running like this for years. I have not reached out to the installed since realizing this, as i want to make sure my understanding of the situation and how to fix it makes sense before i make any accusation that it was installed incorrectly.

My understanding of it, is that there should be a check valve that prevents the water from being pumped up the return back to the panels. it seems like this not only would prevent the solar from draining when the pool pump is running, but is actually forcing water up on the panels constantly. Could this lead to any damage to the panels, or the relief valve on the roof that is designed to be letting air in when they drain? I always wondered why, when i turned my solar on for the first time all day, the water came down excessively hot, but i just always assumed it was because it was the first batch of water pumping through very hot panels, not that that water had been sitting in the panels for hours on a hot roof.

Is this something i should reach out to the installer to cover my Rear, or simply order what i need and install it and move on. The panels are heliocol.

Here are some pictures of the setup. The blue valve is obviously off because of of the issue in order to stop flow to the panels right now (since it is plumbed in this weird way) but it would normally be open. Also, there is no pipe presently coming off of the 3 way valve because that pipe got damaged and i noticed all this while i was about to pull the valve off to replace it.

Below is a diagram, based on my i understanding of how the water would flow when the solar is off, with my setup beacuse it has no check valves. Below that, is how i think it should flow when the solar is 'off.' Below that, is how it would flow when its 'on'. It seems like it works fine when its on, its the off position where the water flow makes no sense. I have an open mind, perhaps i am wrong and its completely normal to plumb solar this way, so if i stand corrected then so be it. I appreciate any insight to confirm or contradict my suspicion.



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