Another solar heater bubble problem.

[bluegirl]

Hi all,
I have had solar heaters installed for about 5 years and this year I am experiencing constant bubbles at my 1st return (I have 3 ). So far I have back washed & deep cleaned my sand filter and switched the VRV from the top of my run to the bottom. When I close 2 of the jets the bubbles stop. My pad is about 5 ft away from my pool & the plumbing to the heaters (4 of them) is on the second story right next ton the pad. This is the first year I have had this problem. Pump basket is full of water with no significant air & the bubbles stop with the heaters off. My pressure with clean filter is 16 & with heaters on is 19. My guess is either the check valve or the VRV. How do I find out which?

 

[pooldv]

I don't see how a check valve could let air into the plumbing. Closing off returns I troduces more backpressure which points to the VRV.

 

[bluegirl]

Is it possible to repair a VRV? Mine is the type with the metal mesh on the end. Hard to see where is is a valve and not just a vent as there are no visible moving parts.

 

[pooldv]

I dont know. There is a ball or similar object inside that is pushed against the opening to seal it. Something is impeding that; debris, algae, etc? Solar Direct sells VRVs.

 

[mas985]

Has the filter pressure changed at all since the bubbles started appearing?

The check valve after the filter looks to be fairly new. Was that recently changed?

switched the VRV from the top of my run to the bottom

The bottom of the supply side?

 

[bluegirl]

The check valve is original with the rest of the system. I did have to replace the diverted a couple of years ago. I have tried the VRV on both ends. What would happen if I completely eliminated the VRV & put in a plug instead?

 

[mas985]

Ok but has the filter pressure changed recently?

You could try plugging the VRV to see if the problem is solved. If not, the it wasn't the VRV. If it does, then it is.

But a VRV should never be installed on the return side of the plumbing unless it is up near the panels.

 

[bluegirl]

So I went up and removed the VRV & put in a winterizing plug. Bubbles are gone. Pressure still 19 as before when bubbles were appearing. Dismantled the valve and found a rubber gasket, a metal disc, a spring and the the mesh cover. Pretty simple the was a small bit of algae on the rubber gasket. Probably that's enough to mess with the seal.