Air bubbles and lose prime when vacuum hose connected

mlucas · Postby **mlucas** » Mon 01 Jun, 2009 18:56

I'm still quite new to the whole pool thing. I don't know a whole lot about the pool because it was neglected for over a year and a half before we moved in. I do know it's somewhere around 10-15 years old. It was disgusting when we inheritated it. the first season was a partial one because we didn't buy the house until the end of July 2007. The pool company came and put a new pump in because the old one was burnt up. It took my son and I 4 days of vacuuming to waste and refilling the pool to get it decent. I struggled on my own using literally hundreds of dollars in baquacil. Wow was that a mistake. Toward the end of the season I switched to chlorine (BBB). Didn't have near the work or money after that. Season two (last summer) didn't have much problem until I forgot to backwash and the pressure got too high on the pump and it was blowing water out of the seams of the pool. I'm not sure if that's what caused my air bubble problem or not. Then towards the end of the season the pipe broke that goes from the multi port valve into the filter and water flooded my pool house. So I called the pool company, they came and closed the pool and said it would be better to work on it when we opened this spring. Well it's this spring and I still have air bubbles coming out of the jets (the main drain is worse than the skimmer) so the pool place put it skimmer only and said they think I have a leak in the main drain just run it on skimmer. Well, that's all fine and good, but when I try to vacuum, the pump loses it's prime. I, personally think it's a leak in the pump, but the pool place thinks it's a leak in the main drain. Anyone have any ideas? Oh, I did mess around with it because it's been driving me crazy and I put it on main drain only and I turned on the pump and shut it off a few times and I would check the basket in the pump and there were like 10 or 20 little tiny stones and some really gross little bleached out leaves. I'm wondering if it could be possible that I have a clog. Would a clog cause air bubbles. I'm not losing any water other than normal evaporation.

Thanks for any and all help.

Postby **Denali** » Mon 01 Jun, 2009 20:17

mlucas wrote:I'm still quite new to the whole pool thing. I don't know a whole lot about the pool because it was neglected for over a year and a half before we moved in. I do know it's somewhere around 10-15 years old. It was disgusting when we inheritated it. the first season was a partial one because we didn't buy the house until the end of July 2007. The pool company came and put a new pump in because the old one was burnt up. It took my son and I 4 days of vacuuming to waste and refilling the pool to get it decent. I struggled on my own using literally hundreds of dollars in baquacil. Wow was that a mistake. Toward the end of the season I switched to chlorine (BBB). Didn't have near the work or money after that. Season two (last summer) didn't have much problem until I forgot to backwash and the pressure got too high on the pump and it was blowing water out of the seams of the pool. I'm not sure if that's what caused my air bubble problem or not. Then towards the end of the season the pipe broke that goes from the multi port valve into the filter and water flooded my pool house. So I called the pool company, they came and closed the pool and said it would be better to work on it when we opened this spring. Well it's this spring and I still have air bubbles coming out of the jets (the main drain is worse than the skimmer) so the pool place put it skimmer only and said they think I have a leak in the main drain just run it on skimmer. Well, that's all fine and good, but when I try to vacuum, the pump loses it's prime. I, personally think it's a leak in the pump, but the pool place thinks it's a leak in the main drain. Anyone have any ideas? Oh, I did mess around with it because it's been driving me crazy and I put it on main drain only and I turned on the pump and shut it off a few times and I would check the basket in the pump and there were like 10 or 20 little tiny stones and some really gross little bleached out leaves. I'm wondering if it could be possible that I have a clog. Would a clog cause air bubbles. I'm not losing any water other than normal evaporation.

Thanks for any and all help.

Hi,

Does the system run fine (except for some air bubbles) when the vacuum hose isn't attached?

I would check your vacuum hose closely for leaks just to make sure that isn't a problem.

If there is a leak at the pump you should see some water around the pump or when you shut the system off, you may hear air being pulled in at the pump.

Another thing to check is the impeller at the pump. With the system off, open the pump and remove the basket. Feel in the back of the basket area for an opening to the impeller. Debris gets trapped in there and when connecting the vacuum hose the extra pressure may cause the pump to lose prime. Make sure the impeller is free of debris.

I'll check back to see if any of this helps. Good luck with it.

Postby **mr_clean** » Mon 01 Jun, 2009 20:39

Well, that's all fine and good, but when I try to vacuum, the pump loses it's prime. I, personally think it's a leak in the pump, but the pool place thinks it's a leak in the main drain. Anyone have any ideas? Oh, I did mess around with it because it's been driving me crazy and I put it on main drain only and I turned on the pump and shut it off a few times and I would check the basket in the pump and there were like 10 or 20 little tiny stones and some really gross little bleached out leaves. I'm wondering if it could be possible that I have a clog. Would a clog cause air bubbles. I'm not losing any water other than normal evaporation.

Thanks for any and all help.

do you prime the vac hose before plugging it into the skimmer? if you don't you will have air in the vac hose which will cause the pump to run dry.

The bubbles coming from the return lines & not going away would mean a suction side leak happening before the pump.

could be as easy as lubing the pump lid o-ring,a clogged impeller, but could be cavitation possibly from the new pump maybe being to big?
What size pump did you get put in?
Did you have this problem before pump was installed?
When you look at the pump lid when the pump is on does the water in the pump pot fill up all the way to the lid?
or does it fill only half way up or three quarters of the way up?
if this is the case only 1/2 or 3/4 this would be why you have air in the return lines from cavitation and air always being in the pump pot.

the pump basically being to strong for the size pipe you have for your pool along with possibly the number of returns lines not being enough so hydraulically it's not going to work correct.

depending on the size of pump you could down size the impeller so it creates less sucking when running.

cloggs do sometimes cause air and if you think something is stuck in skimmer line or main drain you can blow air through lines from pump.

get air compressor with nosle that blows air go to pump remove lid & basket. Take nose & rap ashirt around it & stick it into the skimmer pipe. Blow air which will cause water to blow out the skimmer & if there is something in the pipe it will come flyin out.

try this & see what happens, know anything beyond pump, filter-heater, would leak water not suck air.

mlucas · Postby **mlucas** » Mon 01 Jun, 2009 21:06

I will try to answer each of your questions as you asked them.

I prime the vac hose the best I can. When the valve is on skimmer only the pump pot is almost all the way up to the lid. When the valve is on half and half it's about 3/4 full and when it's on main line only it's about half full. I have 3 return lines but only 2 are used. The other I guess is an extra one. When the pool co. came to open the pool they had to put on a new multi port and after that they opened the pool and the kid opened the wrong return. One had water coming out the other one didn't. So we closed that one and put in the spout for the other one. The pump looks like it says 1.0 hp.

Can I use the air compressor on the main line also, or is that only for the skimmer?

Postby **mr_clean** » Tue 02 Jun, 2009 09:29

if you have a main drain cover then no need too.

when you vac, you need to have the valve turned to skimmer only so you do not share suction with the main-drain as suction would be less & not good enough to vac.

what type of valves do you have? their name? some can go bad/leak.......

as for 1hp pump should only be used with 2" pvc pipe or bigger if you have 1-1/2" pipe & 2-3 return lines could make pump cavitate.

when looking through pump lid water should be up to pump lid with little or no air in it.

mlucas · Postby **mlucas** » Tue 02 Jun, 2009 10:29

There is no main cover, if you mean one that covers it for the winter.

I always have the valve turned to skimmer only for vacuuming.

The valves are new.

The pipes are 2".

The reason I asked if the air compressor is because I turned the valve to main line only and turned the pump on and off a few times and got a bunch of bleached out leaves and some small pebbles. So I was thinking there may be a clog.

I'm really grasping at straws here, because I don't even want to think of the possibility of having to replace the main drain under the pool.

Postby **mr_clean** » Tue 02 Jun, 2009 18:00

so when you have the valve turned to "skimmer only" the pump goes dry?

try loading the vac with water at a return line so it's fully primed as a lot of people do not like to prime vac hose with their mouth & see if this still happens.

Does the pump stay primed?

even if you prime vac hose bad a new pump should self prime the system back up after a few mins.

If this does not work look inside skimmer how deep is it? Some skimmers which are old are shallow & when hooking vac onto a diverter valve in a 1-hole skimmer can suck air as it will stick out of water.

when pump is primed and vac is primed & your able to vac. is it only returning bubbles?

lift vac hose out of water in small sections at a time, "when it is able to vac" & listen for air leaks but not removing bottom of "vac/pole of course". If you hear air it's the vac hose leaking & buy new one.

when you are running your pump it should not cavitate meaning have water go down 1/2 or 3/4 in pump pot
when valves skimmer/main drain are sharing suction.
when you only run main drain this can happen and lower only a little do to pressure.

I think the air bubbles in your return lines when your pump is running is caused by cavitation meaning the pump is to big for your system. When replacing an "old pump" with a "new pump" it is "normal" to down size to a smaller pump as the new one's are much stronger and will cause this problem.

you can down size your impeller to a 3/4 or 1/2 which in many cases will fix the cavtation problem only costing a few bucks.

if main drain had a leak you would loose water & yes you can blow air

mlucas · Postby **mlucas** » Tue 02 Jun, 2009 20:11

The pump doesn't go completely dry, but it does get real low. I can feel some water going through the hose and it will actually vacuum for about 2 minutes then the suction is gone. There is enough suction to keep the hose over the skimmer but not enough to suck up anything in pool.

I have been very creative in priming the hose, so I am pretty sure that it's been primed good. I also bought a new vac hose the other day. There is however a crack in the part that the hose goes into that goes over top of the skimmer. But it is under water and it catches quickly by the suction when put into place.

When we bought this house it was the end of July 2007 and the pool was nasty. The pool company came and put a new pump in because the old one was burnt up. God only knows what was in the pool because it was left uncovered and not running for several months before we got it. It took my son and I 4 days of vacuuming to waste and refilling the pool to get it decent. It was running pretty good that first season. Last summer (2nd season) was when I started having trouble with it.

I'm really starting to believe that, by newbie mistakes of my own, letting the pressure get too high and not backwashing when I should have has blown the seal out in the pump. There has been quite a few times in those first 2 seasons that water would be spraying out of the seam where the motor is connected to the pump. Especially if you say that I would be losing water if there was a crack in the main line. I haven't lost any water other than normal evaporation and when I backwash.

As far as the size of the pump, for some reason I am thinking that it had like a 1 1/4 hp that was bad when we moved in and they replaced it with the 1.0 hp pump. But that I could be totally wrong on. I do know they charged me $800 for this new pump. $500 for the pump with a 5 year warranty and $300 for labor. I found the same pump on ebay for like $129 later.

Postby **mr_clean** » Wed 03 Jun, 2009 09:01

just because you allowed pressure to get to high & water leaked out the gasket does not mean it "the gasket is bad" as it would still leak now.

I have not seen your set up or how close or far your equipment is from the pool, you say the valves have been changed which sounds like an older pipe set-up "indivudal valves (water-spickets maybe) sharing the pump suction", the pump is new/year-old, the pipes are 2", you have three return lines but one is shutoff/does not work-so 2-return lines, you are not loosing water, you have air bubbles in return lines that work and the pump does not have water in the pump pot all the way up to the lid and goes down more under pressure.

sounds like cavitation bro, talk to a pool tech in your area about down sizing your impeller should be around $100 for impeller/install. I would ask for impeller that would go to same brand but 1/2-hp pump & see what happens.

last post here for me bro, you can believe it or not believe it.....................

forboon · Postby **forboon** » Thu 04 Jun, 2009 17:37

I was looking around this site for numerous problems I have had and figured i'd at least give back some that I have learned. I had little pressure coming from my returns and small bubbles too. was worried there was a suction side like. eventually my creepy crawler wouldn't run, my pump would completely lose its prime and there was no water flow. in desperation I took the pump apart (was quite easy) and realized 2 of the four impeller sections where clogged. with a wire and about half an hour I unclogged it and the pump runs twice as good as it used and there are no bubbles. there's no way i could check the impeller or clear the debris without opening it. any handy person could do it, i think