Air bubbles coming from return (from crack in pump pot)

[AnnaK]

Something I read in another thread triggered my memory that I had wanted to ask you about this.

When I vacuum my pool (manual vacuum) there are small air bubbles shooting out the return jet, enough of them so you can see the stream of water coming out. Vacuum suction is fine and the pressure gauge is ok. It moves from 5 psi (normal on the LO setting) to 14 psi (normal for the HI setting).

I had not noticed this happening last year and I haven't changed anything. It seems that something is sucking in air during the vacuuming process but I don't know where or what to check. The plate that goes over the skimmer basket and which the vacuum hose is attached to is on so tightly that I have to shut off the pump to take it off when I'm done.

Can you help me with some ideas on what might be going on?

[chrisexv6]

My pump recently started doing this. In my case it turned out to be the drain plug on the pump itself. I had lost the o-ring on it, and forgot to add some RTV sealant before starting everything up. Worked fine without bubbles until the added suction (and a little cavitation) when the vacuuming started. Easiest way to find something like that is cycle the pump on and off. When you cycle it off, water will tend to "back out" of any leaks that you might have. Sure enough, I watched a couple drops of water come out the drain plug on my pump.

Another possibility is the cuff for your vacuum hose. The swivel cuff is meant for the vacuum head itself, as it is not sealed. Make sure you have the swivel end attached to the vacuum. Its also possible that even the sealed cuff has become a little less sealed and is sucking air while vacuuming.....my guess is you would hear that though.

Try the pump cycle option to see if you see any water dripping. Then Id try to see if you can get a known good vacuum hose after verifying all of the connections on the current one are correct.

-Chris

[AnnaK]

There's a drain plug on the pump? Guess I better go look at that and see if I can find it.

I do seem to have a small leak on the hose that comes out of the light fixture and that leak is new this year. I hadn't done anything about it because it's just a very minimal occasional drip.

As ro the vacuum hose. A swivel end and a fixed end? I think the ends on mine are both fixed though the vacuum head has a swivel point of attachment for the hose.

Thanks for the tips, they'll get me started.

[AnnaK]

Chris,

I can't locate any drain plug on my pump. This is a Pentair 2-speed. The pot sits in front of it and there's a puck chlorinator plumbed in but I have that turned off.

There aren't any leaks that I can see on any of the PVC pipes or the hoses other than that slow drip from the light. I think that's supposed to also function as a return but the valve on that pipe has always been turned off.

My husband is only home on weekends. It's my job to maintain the pool and I'm doing great with the water chemistry, but this mechanical stuff escapes me.

[chrisexv6]

All of the diagrams of Pentair 2 speed pumps that I see have a drain plug. They are normally located in the bottom of where the water comes into the pump (the place you empty the basket from).

As far as the vacuum hose, all of the ones Ive seen have 2 different ends (usually different color too). One of them swivels and the other doesnt. That is in addition to the swivel connection on the vac head itself.

How many bubbles are you seeing thru the return? Can you hear air in your multiport valve? (will sound like a crackling noise). Try taking a length of garden hose and put one end on each pipe and the other to your ear. Try the inlet to the pump, then from the pump to the filter. If there is air you'll hear the crackling. If there is no air in the inlet (possibly more than one inlet to try depending on your pipe setup) but the air shows up from the pump to filter, you've narrowed it down to something in the pump. Thats actually how I started to narrow down my suction leak. Even the little drain plug leak was pushing a decent amount of air into the pool.

-Chris

[AnnaK]

Found the plug, Chris. It's on the pot and for some reason I never thought of the pot as part of the pump but in looking at it closely, it clearly is. No leak there, though.

I pointed my husband to this thread and he wrote back that "we'll be doing some detective work this weekend."

The hose I use for manual vacuuming has two white ends and neither swivels. It's the same kind of hose I have attached to the filter for when I backwash/rinse. I'm guessing this is not a vacuum hose then?

Thanks for working with me on this. I'll post if/when we find the cul[rit air leak.

[waste]

Anna, how are you- other than the air? I 'bookmarked' this post last night, in case that Chris' excellent advice didn't work. You can take a bucket of water, or better yet - a garden hose turned on just enough to 'dribble out' and slowly pour the water on any suspect plug, fitting, the pump lid... and see if the air bubbles lessen - this will pinpoint the air leak.

Another possibility is that you have an obstruction in either the vac hose or the skimmer hose, in which case the water is cavitating thereby producing the bubbls.

I wish you and your husband well with the 'detective work' this weekend, if you need any more help - you know where to find us

[AnnaK]

Just wanted to give a quick update.

There is probably a leak in the pot housing. It's dry around the plug but water collects on the lip at the very bottom of the pot. We turned off the pump, closed all the valves, drained and dried the pot and inspected it as best we coul. No cracks that we could feel or see.

After everything was put pack together and the pot filled and closed, dang it if water didn't appear on the lip again! So there is a leak but I just cannot imagine it would shoot as many air bubbles as what I get when there's suction. It makes a visible, opaque stream of tiny little bubbles.

So . . . waiting for the weekend to work on this some more.