Pool Therapy jets not sucking air, and adding an overflow

[vtsmike]

I have a 4 year old in-ground pool that had a leak in the in-floor pop up system. 1 zone was plugged to prevent the leak, and it has worked. The leak detector company re-plumbed the gearbox for the pop-ups, and now instead of 5 good zones, we have 2 mediocre (large) zones.

Anyhow, I share that because when they put the thing back together (all fittings were removed to 'plug' outlets and inlets to isolate the leak) the therapy jets do not work. There are 2 main return lines for the jets, and 1 has 2 jets, the other has 2 and a regular return nozzle. When the 'air intake' is opened on the deck, it blows water instead of sucking in air.

I asked them to figure out what they did, and they could not, their cure was to leave the jets out of the pool. I have put them back in, but they still do the same thing. I asked about 'priming' it, and that was left with a shrug.

I have inspected the jets, and they don't seem to have any moving parts, but since both separate lines, and 4 different jets all started doing this at the same time, I am perplexed. There appears to be the same amount of pressure coming in on the return lines as before the leak repair.

Lastly, hopefully unrelated. I want to put a PVC tee for overflow control in the relief pipe that comes up out of the ground. I was told by the builder this line is tied to the 2 main drains (probably 1, just 2 openings) as a 3rd spot for relief. But, there are 2 pipes that are about 4-6" above the pool deck level. 1 is capped with a plug, the other has a vented tee with 'screens' on it. I suspect I can install a tee at the maximum water level I want, and pipe it away from the pool and down, into rocks. I would like to hear - yeah that's right from someone. But, what is the other pipe with the solid plug?

I can't remember what I have in the signature, so: 17,200 gal in ground, 17X27 rectangle, solar heat, 1-1/2HP pump, cartridge filter, Zodiac Salt Chlorinator, in-floor pop-ups.

Thanks.

 

[Poolsean]

An absolutely uneducated guess would say that you have too many heads on one zone and not enough pressure to pop the heads up properly. Therefore with the heads being not full raised, there is extra back pressure that is forcing more water to return via the jets, but there too, there is too much back pressure with the return wall fittings attached, thus causing the water to take the path of least resistance, your air injection fittings.

My guesses are based upon the information you're providing.
Can verify if your floor heads are all fully extened up when it hits those zones?
Did you say that AFTER you replaced the wall fittings, the system started blowing water out of your deck mounted air control fitting?
Conversely, when you have the wall fittings off, there is no water coming out (but it's possible that the floor fittings are all still not fully extending up.

Why did they reduce your systems down to 2 large zones, rather than 3 normal zones and 1 large zone?

 

[vtsmike]

Partially working jets

Thanks for the input.

I have 3 return lines from the pump, each with a valve. 1 for 2 outlets in the deep end. 1 for 3 outlets in the shallow end. 1 for the pop-ups.

I went back out, and removed the jets, and tried to see how they work, I have no idea, but I did find out that when properly installed, they have about 1/16 of a turn for gradually on and off. There are moving parts, the guts rotate. Anyhow, previous to the pop-ups being rezoned, the jets had very good air intake, and air bubbles. We would typically use the deep end jets, and turn the other 2 valves off. Now 1 of the 2 in the deep end is actually working. They share the same air intake, so I don't know why the other does not work. With only that return line open, and I put my hand over the jet with no air coming out, the other jet stops taking in air, and water comes out the deck. And vice versa. I have no idea how these things work, but it seems strange that if we had run the 1 return line only in the past and it worked fine, and now running on that same line, only 1 jet works.

Likewise, in the shallow end, 2 of the 3 jets started putting out air.

At this point I am suspecting that maybe the things were not screwed all the way in. There is a rubber type seal on the back end, that must seat and seal when screwed all the way in.

The pop-ups do not seem as powerful as before. They do pop all the way up when on. I am guessing the gearbox got boogered up when they did all this, and between that and the rezoning of the 'dead' zone that was sealed because of the leak, we ended up with an incorrectly working pop-up system. Since we were losing quite a bit of water with the leak, we are probably happier with it sealed, than working properly.

As for the other question, I am still interested in knowing about the overflow set-up.

Thanks.

 

[Poolsean]

The wall returns are most likely connected to venturi jets. These are designed to suck air in, via your deck mounted air adjustment fittings.
With the fitting screwed down all the way, they are not suppose to draw air in, so no bubbles. As you open the fitting, it allows air in by drawing it in via venturi action. The more opened they are, them more air they will draw in.
If you have a restriction on the return jet, or simply stick your hand over the return jet, water will be diverted out of the deck through the fitting, as you're seeing.

Some types of pop up systems use an in line union with a strainer screen to block debris from ruining the pop up zone valve assembly. You may want to check this.
If your filter needs to be cleaned or there is debris clogging the impeller, it will slow down flow and make everything work as you're describing too.