Return line bubbles

Jul 15, 2007
64
Florida
My shortest return line (strongest output) has been spitting out bubbles for about a year now and was wondering what the symptom is and how to fix it. Pool has 5 return lines total (including Polaris connection) but this is the only one with bubbles and not flowing out smoothly. Output flow still feels strong though. I've also attached a pic below. Thanks for any advice.
 

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If the bubbles only last for a little while when the pump starts up they can come from the filter or solar panel and are not a problem. Constant bubbles can come from a vortex drawing air into the skimmer, a poor seal on the pump strainer basket lid, or a suction side plumbing leak. SWGs also cause bubbles when the cell is active, however SWG bubbles are normally much smaller than the ones in your picture. Regardless of the source of the bubbles it is common from them to only come out of the first return, or sometimes the first two returns, if your returns are plumbed on a single pipe run.
 
I too have bubbles (start up this past September) and builder could never come up with a solution. Mine is also in the first return line and as JasonLion said, mine didn't start until I activated the SWG, so I am assuing that this is where the issue is created.
 
The first or strongest return is nothing more than the law of hydraulics. A constant air stream is a sign of air intake somewhere. A bad pump seal is not going to leak air, it will leak water. Try this.

1. Make a visual on the pump lid o-ring, the intake pipe at the pump, and the suction valve if one exists. With the pump on, turn it off while looking at those areas. It's likely you'll see water eject out. That is your suspect area.

2. If that does not reveal anything and you have a suction diverter, go for that specifically. If there is an actuator, remove it. With the pump on, look at the stem where it comes through the cap AND listen after turning off the pump. This all has to be done quickly. Check the cap as well.

No visual signs of water in this process most likely means you have an underground suction leak.
 
repair_guy said:
1. Make a visual on the pump lid o-ring, the intake pipe at the pump, and the suction valve if one exists. With the pump on, turn it off while looking at those areas. It's likely you'll see water eject out. That is your suspect area.
Just to clarify, are you referring to the o-ring/lid of the pump basket? Isn't this supposed to spurt out a bit of water when the pump is turned off? That's what my pool builder told me. He said not to tightness the glass top to tight, and also states so on the lid. I take this to mean that it's a bit of a pressure relief, but I'm no engineer. I have absolutely no problems with bubbles of any kind with this issue.
 
ivyleager said:
Isn't this supposed to spurt out a bit of water when the pump is turned off? That's what my pool builder told me. He said not to tightness the glass top to tight, and also states so on the lid. I take this to mean that it's a bit of a pressure relief, but I'm no engineer. I have absolutely no problems with bubbles of any kind with this issue.

No, it isn't supposed to squirt water, but if there are no bubbles you aren't really going to have a problem. If water squirts out the seal isn't good enough. You can over tighten them and cause problems, so if you aren't having problems with bubbles or loss of prime you are okay.
 
Air is not supposed to squirt out. If it squirts out, it sucks in. As strong as you can tighten that lid is not going to break it. A tight lid will probably snap your wrist first.

If the lid o-ring squirts, replace it. You don't say what brand it is, but if it squirts, it has to be a Hayward or a StaRite. The NorthStar with the t-seal is pretty common too. Lousy design from the bottom up.
 
I think water squirting out of the Northstar after it is shut off is pretty common. Both of mine have done it since they were put in three years ago. I have heard of others who experience the same thing as well. The lid is releasing the pressure inside the pump basket area and does not cause any harm other than make the pad slightly wet. I am not sure if this is really a design defect but it wouldn't surprise me if they did this on purpose to reduce pressure waves inside the pump when it is shut off.

If the pump leaks when it is running then that is a totally different issue and should be corrected.
 
repair_guy said:
Air is not supposed to squirt out. If it squirts out, it sucks in. As strong as you can tighten that lid is not going to break it. A tight lid will probably snap your wrist first.

If the lid o-ring squirts, replace it. You don't say what brand it is, but if it squirts, it has to be a Hayward or a StaRite. The NorthStar with the t-seal is pretty common too. Lousy design from the bottom up.

My NorthStar with t-ring seal squirts upon shutdown, too. Wouldn't that condition (i.e., lack of completely tight seal) allow air to be sucked in during operation?

pj
 

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My NorthStar with t-ring seal squirts upon shutdown, too. Wouldn't that condition (i.e., lack of completely tight seal) allow air to be sucked in during operation?

Not necessarily. Most IG pools will have negative pressure (pump running) inside the pump strainer basket which, while it certainly can suck in air if the seal is faulty, tends to actually tighten the seal if it is in good condition.

When you shut the pump off, that negative pressure inside the pump is now gone so the seal is loosened allowing it to spurt water. That said, A good seal should stay watertight in all cases so it sounds like you need to replace it.

There may even be some instances where shutting off the pump creates a momentary positive pressure against the seal and I would think even a good seal would leak under those conditions.

If your pump is left off for hours, does air get into the system?
 
If your pump is left off for hours, does air get into the system?

No, the pump stays full of water.

There may even be some instances where shutting off the pump creates a momentary positive pressure against the seal and I would think even a good seal would leak under those conditions.

Probably so, as I've got solar panels on top of a two story house. My old pump never leaked at shutdown, though.
Maybe it's just a crappy seal design. I'll try some pump seal lube on it; it's more of an annoyance than a real problem, I guess.

Thanks for the reply...

pj
 
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