Need help with returns and pressure issue

[Finkle]

Hello, I am new to the forum, but have already learned so much. I would just like to thank everyone for all the help I have already received just from reading through other people's issues. I am new to pools; as many others, I became a pool owner and a home owner at the same time. Please forgive any ignorance on my part.

Attached is a photo of the plumbing setup for my pool. I have a 22,000 gallon inground vinyl liner pool, with a pentair whisperflo 3/4 hp pump, a DE filter, and in line chlorinator. As you can see from the photo, I have three suction lines (skimmer, main drain, and what I assume is a dedicated vac line on the wall of the pool). There are two discharge lines after the chlorinator, which both branch out to two lines before the pool for a total of four jets in the pool; two in the steps and two on the wall (the steps are paired and the wall jets are paired). Normally I have the three way valve set to split evenly between the two lines. My normal operating pressure is about 14-15 psi. With this setup, one of the two wall jets never really had any good flow (it happens to be the furthest line from the equipment). Recently I had an issue with an eyeball on one of the jets at the steps was stuck on, and when I tried to remove it, the fitting between the eyeball and the steps started spinning with the eyeball. I was able to remove the eyeball, and I retightened the fitting. Now, I suspect I may have a minor leak (which has been really hard to diagnose as we've had really hot days, so I can't tell if its evaporation and we've had a lot of rain also, so I can't let it keep going to see where it stops). Also, my pressure is now at about 8 psi split even, the same if I discharge just to the steps, but it shoots over 20 psi if I discharge just to the wall jets, and I finally get good flow at the one jet that never seems to. It also seems like there is less disturbance/cavitation in the pump basket when aligned to the wall jets vice the steps.

So my question is, is this just an alignment issue or do you think i have an issue/leak at the steps, or a clog at the wall jets? I recently backwashed, so the 8 psi is a fresh pressure.

Any help is greatly appreciated.

[attachment=0:1k1dse34]photo (2).JPG[/attachment:1k1dse34]

 

[duraleigh]

Welcome to the forum. :lol:

Probably the easiest way to address that issue is with varying size eyeballs. You can get them in 1/2. 3/4 and full inch, I think. By restricting the flow to the ones currently flowing the best, your water will be directed more to the others.

Your psi may change some but that is not relevant and won't hurt a thing.

 

[Finkle]

Thanks, I'll give that a try. Im not so concerned about the filter pressure reading lower than it had before, but I'm still not sure why I see such a drastic change in pressure based on how the discharge diverter valve is positioned. Both lines are the same size, its almost like there is a blockage in one, but how would that be possible on a discharge line? I guess I'll try the different sized eyeballs and go from there.

Thanks again for the advice

 

[Bama Rambler]

Can you give us an overall layout of the pool and equipment?

Depending on how it is plumbed you can have a significant difference in flows between the returns. And since you say the fartherest return is the one with the least flow it makes sense.

The fact that the pressure stays low when the flow is diverted to the steps but jumps to 20 psi when diverted to the wall returns could indicate a blockage. Even with one line being a lot longer than the other still wouldn't account for that much difference in pressure if everything else is equal (i.e same sized eyeballs, etc.).

 

[Finkle]

Dave,

Attached is a diagram of the layout of the pool, the above pic shows how it is physically arranged. Don't worry, i was not running with the valves set that way

So, I was thinking maybe there was a blockage as well, but of course being the longest run it may be difficult to clear if that's the case. That line splits underground, and only the one jet has flow issues, I get fairly good flow at the closer wall return. So if it is a blockage, its after the "T". I believe all the return lines are the same size.

Are return blockages common? I'm not sure how something big enough would get past the filter to block the line. I was also thinking maybe it was an issue with the valve, but if that were the case I would think I would see a problem at both the jets on that line.

Thanks again for the help.

Nick
[attachment=0:3b2kljlx]Pool Diagram.jpg[/attachment:3b2kljlx]

 

[Bama Rambler]

What size eyeballs do you have in all the returns?

Depending on how they actually routed that fartherest return it could have a lot of flow restriction. What happens if you close off the step returns and plug the closest pool return? How much flow comes out the furtherest return? And what's the pressure?

 

[Finkle]

I'm not 100% sure, but I believe all of the eyeballs I have in are 3/4".

For most of the beginning of the season, I had been running at 14-15psi (which is the "clean" mark on my filter gauge) with the valve set halfway between the steps and the wall. Now for some reason i've dropped to about 8-10 psi with the valve at halfway, and that pressure does not change if i use just the steps. However, if i align just to the wall i see a pretty big jump to about 25psi. I have not closed off or restricted the other wall return, but I'll give that a shot and see if anything changes. I suppose i could align the valve at about 70/30 wall/steps to get back to around 15psi, but I think i might be avoiding not solving the issue. And even at that, there is still not much flow at that jet.

 

[Bama Rambler]

Have you checked the impeller to see if something is partially clogging it?

Also check the eyeballs to make sure they're all the same size.

 

[Finkle]

I haven't checked the impeller other than sticking a finger down in there, but it's tight and hard to tell if anything is in there. I seem to be able to spin it somewhat freely. I suppose I could just take the pump apart, I have unions on either side.

I'll double check the eyeballs as well.

 

[Finkle]

Actually with the discharge on top I can remove the motor without breaking any plumbing.

 

[vinper]

In that picture ,valve handle , looks like you either have only the skimmer or main drain on not both .. is your pump not starved for water your lines are reduced at the ground in size assuming the 3 way valves are piped sized 1 1/2" ?that would make your return lines 1 1/4".....

 

[vinper]

what happens when you just plug with your hand .the wall return closest to pump . Does the other get good flow?

 

[Finkle]

All eyeballs are 3/4". As far as I can tell, all underground piping is 1-3/4" and above ground piping 2-1/4".

Yes i was running with the skimmer/drain valve at about 80% skimmer because otherwise i didn't seem to be getting the flow into the skimmer basket i thought I should. That said, I have now set it to 50/50 and it seems that the pressure may be back up to about 12psi.

So, i set the return valve to 50/50 with poor flow at the far return. I set the valve to 100% to the wall returns, covered the close return and could see across the pool that the flow was stronger, but unfortunately there also seemed to be some bubbles coming out as well (this only happened when I covered the close return). With the starting pressure higher at this setup (27psi about), the chlorinator starts leaking water from the top, i guess being the weakest point (maybe the o-ring needs to be replaced there). So, i had to crack the valve to the steps a bit to relieve that. The pump/filter equipment is not close enough to the pool to read the pressure when covering the close return, and my wife was occupied with my 13 month old, so I was flying solo. If I set the return valve to 70/30 wall/steps i get fair flow to the far return, but the steps are still flowing very well. No matter how I align everything, I can never get the flow as good at either wall return as I get at the steps. Even the close return never gets that strong.

 

[Bama Rambler]

I would change those wall return eyeballs out to 1" Especially the fartherest one.

Understanding that the diagram is just that and there's no telling how they actually ran the piping, I can believe that the step returns are always going to be the stronger flow. There's an extra 90º el in the wall return line before it even enters the ground so there's no telling what gyrations it goes through before it gets to the pool wall.