Bubbles When Vacuum Is Running

Jump to latest Follow Reply
M

Mark L

0
Feb 21, 2014
4
California
Hi
I just built a pool at my house and when the vac is running I see air bubbles coming from the suction line into the pump. When I switch the valve over to the skimmer it stops so the problem is with the suction pipe coming from the vacuum connection (it's a dedicated line 40' long with 2 sweep 90's and then connect to a Jandy valve prior to entering the pump ) After doing the basic troubleshooting;
Checking hose for leaks
checking pump and valve for leaks no improvement.
Tried different pump speeds, lower speed helps a little but doesn't stop it
I suspect a possible restriction in the pipe so I removed the Hayward thread in wall fitting from the pool to look inside pipe and bubbles stopped!! . Reinstall the fitting and the bubbles return immediately
It appears that any restriction causes bubbles

Any ideas
 
Welcome to TFP :)

It is normal for the suction cleaner hose, they are friction connections and are not alway air tight, as long as the air bubbles are not filling up the pump or filter and restricting flow you are good :)
 
well that is interesting, it is all under water right? I have no idea how it would get air completely under water unless you have a suction side air leak and when you constrict water flow it is sucking air somewhere in the line... they are a pain to find but can be done..

Pool School - Suction Side Air Leaks
 
cowboycasey said:
well that is interesting, it is all under water right? I have no idea how it would get air completely under water unless you have a suction side air leak and when you constrict water flow it is sucking air somewhere in the line... they are a pain to find but can be done..

Pool School - Suction Side Air Leaks
Click to expand...




How likely is it for a pipe buried under 2' of compacted dirt to leak air into the pipe???
 
How likely is it for a pipe buried under 2' of compacted dirt to leak air into the pipe???
Click to expand...
Virtually impossible.

I scanned your response perhaps too briefly but what makes you think the vacuum hose is not sucking in air? It is easily the most common problem.
 
duraleigh said:
Virtually impossible.

I scanned your response perhaps too briefly but what makes you think the vacuum hose is not sucking in air? It is easily the most common problem.
Click to expand...

I removed the vac hose and held the flap open and ran the pump. Still had bubbles. Then I removed the threaded on wall fitting so there was just an open pipe and the bubbles stopped. Put the fitting on and the bubbles returned
 
There is an air leak somewhere between the Hayward threaded fitting and the pump. The fitting is providing enough restriction of water to the pump that it is pulling air into it somewhere in between. To start I would first lube the pump basket lid o-ring and pump drain o-rings. If that doesn't stop it your problem may be worse. How much of the pipe is exposed?
 

Enjoying this content?

Support TFP with a donation.

Give Support
There is an air leak somewhere between the Hayward threaded fitting and the pump. The fitting is providing enough restriction of water to the pump that it is pulling air into it somewhere in between.
Click to expand...
Well, of course. Thanks for that, Pool Tool. and Mark L, I apologize that I couldn't envision what Pool Tool has posted....I think he has nailed it.
 
Isn't it possible the pump is being starved for water with only a single suction providing the pump and cavitating? I can't use my vac port or even just one of my skimmers to vacuum without cracking another skimmer open. Just not enough water. This is with the pump on high. On low I can .
Kris
 
Bubbles in the returns are not caused by cavitation. When a pump cavitates, it creates vapor bubbles but these do not exist outside of the pump impeller. They collapse immediately as they travel from low pressure to high pressure inside the impeller. The ONLY way to get bubbles out of the returns is when air is getting sucked into the plumbing system.
 
mas985 said:
Bubbles in the returns are not caused by cavitation. When a pump cavitates, it creates vapor bubbles but these do not exist outside of the pump impeller. They collapse immediately as they travel from low pressure to high pressure inside the impeller. The ONLY way to get bubbles out of the returns is when air is getting sucked into the plumbing system.
Click to expand...
he only talked of bubbles in the pump... Not coming out of returns.and they would go away when an additional water source was introduced.
Kris
 
Ok but that is still not cavitation. And if air is getting in the pump basket, it will eventually make it out the returns. It has no where else to go.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply