Air in jets when running solar heater

[Bart]

Lately I've noticed a steady stream of very tiny bubbles comming out of my jets when I run the solar heater. I did a test last weekend where I turned the solar off but kept the pump running and instantly the bubbles disappeared. After a half hour or so, I turned the solar back on and instantly the bubbles appeared. I called the solar guy and he said it could be due to my filter being clogged. The pressure is a little high and I was going to backwash it this weekend anyhow, but I'm just looking for other opinions or a sanity check here.

Is this being caused by a dirty filter or is there something else happening here?
Could it be sucking in air somewhere along the piping and heating pannels on the roof, or would I see water leaking out?

Thanks!

 

[cramar]

Maybe some info on your plumbing set up will help others comment (is it a mixed feed or a dedicated return, panels on roof, etc)

On my solar set up I have a dedicated return from panels to the pool and when I get bubbles coming thru it's usually due to not enough pressure in the line therefore throttling the valve so more water is directed to the solar panels solves the problems.

 

[mas985]

A dirty filter can reduce the pressure at the vacuum release valve and allow air to enter the system. Clean the filter and the air should go away.

 

[Bart]

Thanks!

 

[jeremymiles]

I agree with the others - I've had the same problem here. Your pump needs to maintain enough pressure to keep the panels full of water - if it's not pumping hard enough, then the panels will suck in air through the vacuum valve at the top. The most likely is a dirty filter (or not enough speed on a variable speed pump).