Air Bubbles in return when solar is on - would love advice thx!

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Andy714

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Jun 2, 2014
10
Huntington Beach
I have an all manual system and when the solar valve is on we continue to get air bubbles in the return lines. I replaced the vacuum release valve on the system. If I turn off the solar the bubbles will go away. It seems like an air leak as the pump has had trouble priming with the system on a few times. Is there a good way to check for an air leak on the solar panels? I don't see any water at all on the roof. Any advice would be appreciated.

Thanks!
 
You should have positive pressure at the panels, you may need to install a test pressure gauge where the water exits the panels to confirm this though, it is possible to have negative pressure at this point if the return line is sized too large. (a simpler, but less precise test is to loosen a fitting there and see if water gushes out while the panel is operating)

Ike
 
What is the pressure on the filter gauge and how high are the panels above the pump?

When was the last time you cleaned your filter?
 
Thanks for the replies. I just cleaned the filter. I have a Hayward Ecostar variable speed pump. At 3000 rpm it the pressure gauge reads 17psi with the solar valve closed, and 22 psi with it open. The panels are on the 2nd story of our house. Its a bit of length from the pool equipment underground and then up the house to the 2nd story. I replaced the vacuum release valve yesterday. Im pretty sure I have positive pressure when the water exits the panels since the solar is heating the pool. I think air is getting in the panels somewhere on the roof but I dont see any water at all.
 
Andy714 said:
Im pretty sure I have positive pressure when the water exits the panels since the solar is heating the pool.
Click to expand...
That is not reason enough. As long as there is flow, the panels will heat. However, it does not always mean that VRV is closed. That is the most likely place where the panels will leak air but at 22 PSI, there should not be an issue unless you have a lot of head loss between the filter and the VRV.

Do you run the panels at 3000 RPM?

Can you describe all of the fittings, valves and plumbing between the filter and the VRV?

Where is the VRV located? Supply or return side of the panels?
 
I do run the panels at 3000 rpm. The fittings between the filter are all PVC with a back flow valves as well. On the roof the panels are connected with PVC and it looks like "rubber" connectors. I am posting a few pics too. I'm not sure what "head loss" is.

photo.JPG

- - - Updated - - -

I had an old Vac relief valve that looked like it was "rigged. I'm pretty sure this is at the return side. I replaced it with the bigger 2" one. Here is a pic of the old one

photo-1.JPG

- - - Updated - - -

Heres what I replaced it with. Is there an easy way to check for air leaks between these fittings?

vac_relief_pool.jpgvac_relief_pool.jpg
 
Those are good VRVs. Same ones I have. Can you take a picture of your pad equipment? Maybe I can spot something there. Specifically from the filter to the solar supply.

Also the VRV looks like it is installed on the high point/return side of the panels. You might try installing it on the supply/lower side of the panels. There is more pressure there to close the valves.
 
Andy714, have you considered replacing the o-ring in the solar valve (valve you turn to send water to roof)? I thinking if this o-ring is bad, your system would suck in air as the water goes up.

I'm having a very similar if not exact same problem. Replaced old 2HP with Pentair VSP. FAFCO Solar. As I start to use solar, getting bubbles thru returns. The amount of bubbles is proportional to the RPM of the VSP. (2200RPM = lots of air, 2300 = less air, 2400RPM and above - champaign bubbles. At 2400RPM PSI is 16. I Replaced VRV. Cleaned DE filter, and also went ahead and replaced o-rings in all my jandy valves. 2 story home (perhaps taller than most with higher ceilings).

I have 2 questions.

1. Do I even have a problem? (I've been told that I should be able to run 2200RPM on my setup and run solar just fine. My goal here is to run at lowest RPM to save electricity).
2. Can someone provide some additional guidance on relocating the VRV. Right now, my (new one) is installed on the highest point on the highest panel (peak of roofline). Is it as simple as relocating the VRV to one of the next lower panels?

Thanks in advance.
 
If the o-ring on the solar valve was bad, water would squirt out, not suck air in. There is positive pressure at the solar valve.

But you should start your own thread instead of hijacking this one.
 

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The video is showing how a vacuum can boil water. That is completely different than pulling air out of solution. Although air will come out of solution before the water boils.

Both can happen in a pump but the first is called cavitation and you will not see air in the pump basket due to this because the vapor bubbles collapse very quickly in the impeller. Pulling air out of solution can happen too but it is a very slow process and takes many hours to develop a small bubble.

So I don't think either of those would apply in this situation.
 
mas985 said:
The video is showing how a vacuum can boil water. That is completely different than pulling air out of solution. Although air will come out of solution before the water boils.

Both can happen in a pump but the first is called cavitation and you will not see air in the pump basket due to this because the vapor bubbles collapse very quickly in the impeller. Pulling air out of solution can happen too but it is a very slow process and takes many hours to develop a small bubble.

So I don't think either of those would apply in this situation.
Click to expand...

Umm,...OK. Post was edited.
 
Have you inspected all your check valves? A bad one on the supply line would drop the pressure before reaching the VRV.

The center one in this pic would be my focus:

photo-1_zps52fbae0d.jpg
 
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