The weirdest thing, when I turn my pump OFF is when my problem starts...

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S

stellsdad

0
May 24, 2016
14
Hudson, MA
Hi everyone,

I'm encountering the oddest behavior. When the pump is on, everything seems just fine. Good suction at the skimmer, good pressure, no leaking, all is well. Since i'm in the middle of SLAM and my pool is in a wooded area, I have to backwash 2x / day. When I turn the pump off, my problems begin: I get a giant whoooosh, water sprays out of my pump basket area. My skimmer bubbles up, air rushes out. Seems like pressure and air have built up somewhere, but only released when the system is powered down.

Here's where it gets super weird -- now my system is clogged. I have a gravity feed to the pump, but no water is coming in. I have to take a shop vac and suck the line for a few seconds before 'unclogging' things and getting water to flow normally. Once this happens, I can run the pump again just fine, no leaks, no buckling or pressure concerns. I don't get it.

The two things I've done this spring to the pool were:
  • Replaced a dying Hayward Superpump 1hp motor with a new energy efficient version
  • Had to replace an 18" section of PVC (the return line from my filter). The new piece is identical to before, only difference is it's about 6" off the ground (where the old one was on the ground). I forgot to snap a picture but I don't think this made any significant alteration to the system

At first I thought maybe a larger clog, so I ran a plumbers snake from the skimmer 3-4 times. It never seemed to hit anything, but admittedly that's hard to determine. Of course I'm concerned there could be a leak of some sort, except there's no water loss with the system on or off (other than the spraying near the pump when I shut it down).

Any ideas? I'm genuinely lost, not sure what else this could be.
 
The whoosh on shutdown is air in the filter tank. It compresses when under pressure and expands the instant the pump is off and shoves the water out. I suspect the air leak is at the pump lid, since that should be keeping water in as well as air out and you say water sprays out. One way to check is to open the air bleed on top of the tank before you shut it off. If air escapes and it doesn't whoosh, you know it's trapped air.

The loss of prime may be how your gravity system is set up. Air could be trapped at the top. I'd like to see pictures. If it is truly gravity feed, you wouldn't be able to open the basket without the pool emptying out through the plumbing when the pump lid is off.
 
AftonJeeper said:
Would love to see a pic of the water spraying because I think that is your issue. Look for a drain plug missing from the pump or filter.
Click to expand...

I'll take a picture, or rather a short video when I get home today. I thought of the drain plug too, but they both look okay.


Richard320 said:
The whoosh on shutdown is air in the filter tank. It compresses when under pressure and expands the instant the pump is off and shoves the water out. I suspect the air leak is at the pump lid, since that should be keeping water in as well as air out and you say water sprays out. One way to check is to open the air bleed on top of the tank before you shut it off. If air escapes and it doesn't whoosh, you know it's trapped air.

The loss of prime may be how your gravity system is set up. Air could be trapped at the top. I'd like to see pictures. If it is truly gravity feed, you wouldn't be able to open the basket without the pool emptying out through the plumbing when the pump lid is off.
Click to expand...

Ahh, interesting. I'm not sure I have an air bleed on my tank?

IMG_20160604_143157_zpsflzedscw.jpg


I'll take pictures later today to show you my gravity feed. You're exactly right, normally when the valve is open, water comes rushing into the pump basket. Something weird is happening to block this flow.

By the way, notice the auto chlorinator in this pic? It goes unused thanks to following instructions from TF Pool; however I wonder if it might be a source for air coming in? I tried removing it from my system, but don't have a good way to plug the two holes it would expose.
 
stellsdad said:

By the way, notice the auto chlorinator in this pic? It goes unused thanks to following instructions from TF Pool; however I wonder if it might be a source for air coming in? I tried removing it from my system, but don't have a good way to plug the two holes it would expose.
Click to expand...

You should be able to buy a cap to put in place of the white compression fitting that is holding the line in place. Hard to tell but it should be either 3/8" or 1/2" compression cap that you need.
 
Sorry for the delay. I thought maybe my problem was getting better on its own. I've had a few successful backwashes with lighter clogs and less "whooshing". I thought maybe this was all caused from algae in the filter, and now that the pool was clearing up the system was running better.

Until this morning, when it came back in full force. Here's a video:
https://youtu.be/LJjJIvfcmCY

You can see at the beginning, there are no leaks, the system is running fine. Before I started filming, I checked the skimmer for suction and the return for flow -- all look great. After filming, I removed the pump lid and had to take a shop vac to the line to get water flowing once more. It's important to note no debris ever comes out of the line. Somehow a vacuum of sorts is created that stops water from flowing.

I'm so confused.
 
Start with the pump basket lid gasket. It looks and sounds like you have an air leak there. And the fact that water can leak out when the system isn't under much pressure tells me it isn't sealing tight. Running it's under 20 psi, so it can't be any higher than that when the pump shuts off, and you figure water will be leaving in both directions, so it should be much much less than 20.

Check the seating surfaces and make sure they're clean and smooth. Really give the gasket a good inspection. One hairline crack is all it will take. Or if it feels stiff and non resilient. If it is well-lubricated. That it isn;t all mushy and swollen from lubricating with petroleum-based stuff like vaseline or WD40.
 
At the beginning there is leaks - that is why there is all the air/turbulent water in the pump basket. The leak is air getting into the basket, which as Richard alluded to fills your filter with air creating a pocket of pressurized gas. As soon as you turn off the pump the pressure drops and that air, compressed into a small bubble, expands forcibly pushing water out to the path of least resistance.

No water should come out of the pump basket like that. It comes out around the lid (lube the seal) and from the bottom (must be cracked). These are all symptoms of something larger going on in your suction piping. My only guess and just a guess is flexible (spa) piping is used from your skimmer into your basket and that it is collapsing and starving the pump of water. Then to try to feed the pump, the suction it is pulling air into any little leak there might be like at the pump basket top and bottom.

Use your suction 3-way valve to isolate flow from the skimmer and main drain presumably to see if one of the other stops causing the turbulent water/air mixture in your pump basket. If one stops the bubbles that will lead you to your problem.
 

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Yes, this is some sort of suction leak. pump lid gasket....if it's not that then likely an air leak
in your incoming plumbing. I had that exact same pump at my last house/pool where this happened.

I had a lousy pool repair guy replace a length of radiator hose with clamps the previous owner
had put in. I had him remove that and make it all pvc and after he finished the day before, when I turned off the pump, the air hammer
reaction blew the lid off the skimmer!

Needless to say that was the very last time i used that pool co.
 
How high is the water level in your pool? You could be sucking in air at the skimmer if the water level is too low. Look for a vortex swirling in the skimmer next time the pump is on. You pool has lost prime after blowing out air and water at shut down. If there is a significant air leak in the pipes or the pool water is very low it is going to have a difficult time priming on start up. Also it looks like the pump is a little bit downhill of the pool, which would contribute to the difficulty priming.

Check all the things Richard320 recommended, make sure the water level is at least 1/2 way up the skimmer opening and that there is no vortex in the skimmer when the pump is on. While you have the pump strainer pot open to inspect and lube, fill it with water to prime the pump, then put the lid back on and re-start the pump. Let us know what happens.
 
Seems like a leak at the pump basket lid. You could try putting soapy water around the lid and see if it gets drawn in when the pump is running. Even if it doesn't, there should not be any water coming out there, so the gasket may need to be replaced. As far as the chlorinator goes, see if one of the hoses is long enough to stretch from the connection before the filter to the connection after the filter. If so, just eliminate the chlorinator and connect the hose direct.
 
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