Air Bubbles in Return Line


New member
May 3, 2012
I am having a lot of air bubbles in my return lines to the pool. I have a AutoPilot Salt Chlorine Generator (RC 35/22) it is see through and i can see a lot of air in the cell. There are no air bubbles in the pump (when you look through the plastic cover over the basket). I recently had all the lines pressure tested by a pool company and they found no leaks.

There is a three way valve imedialtely after (in line with ) the salt chlorine generator cell before the water goes into the pool. This three way valve controls which returns get the water. There are 4 returns so you can have two on at a time or leave the valve in the middle and then all 4 returns shoot water out.

The interesting part is the when I turn the valve all the way over to only use the 2 returns in the steps of the pool no air comes out, when i turn the valve to 50/50 or on the two other returns outside the pool steps the i got a lot of air.

How is this possible? It is not on the suction side so how can air come into the system. If there is a leak wound water shoot out somewhere?

Please Help


30'000 Gallon Salt Water
AutoPilot Digtital Nano Salt Water Chlorine Generator
AquaCal Heat Pump
CoPilot Ozonator
Jandy 1.5 HP Model#PHPM1.5
Candy Pool Filter Model#DEV48


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Salt Water Chlorine Generator's generate bubbles when on. See if the bubbles stop when your Generator is not on (but the pump is on). If no bubbles -- no worries.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

I suspect that when you have all four returns open the flow is less and that allows you to see the bubbles easier. When you have the return water only going to two of your returns the pressure goes up and makes it harder to see the bubbles.

As mknauss says, if the bubbles are only there when the SWG is producing chlorine, then you have nothing to worry about. I'm not familiar with your specific SWG, but most of them turn on and off every few minutes based upon the percentage of output you it set for.

Jim R.


TFP Expert
Platinum Supporter
LifeTime Supporter
Moderator Emeritus
Aug 10, 2012
FL panhandle
Agreed. My SWG makes plenty of bubbles. Turn it off and see what happens. The other two returns might be capturing the bubbles somewhere and will give a big bubble sooner or later.


Aug 8, 2016
San Antonio
I am absolutely brand new to pools and most of this is Greek to me. However just after we bought the house our pool started to blow bubbles out the jets. Not sure if that's what you are talking about or not. I found out my water level was to low and the skimmers were sucking air. Once I got the water level back up where it was suppose to be it quit. Again brand new but thought this might help.
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