Main Drain not seeming to work in new construction

Oct 9, 2015
41
baton rouge
I just had a new pool constructed and started up this week.

Communications with the builder has not been the best, and the turnover was fairly simplistic.

After they left, they said to sweep/scrub the pool daily towards the deep end so that sediment from the plaster work will be drawn into the main drain and filtered out. This is very fine particulate and mostly produces a small cloud when swept. However yesterday being the first day I noticed that there was no visible intake of this cloud or smaller debris that would float right over the main drains. I went to the equipment and noticed that the valves were set so that suction would mostly come from the skimmer with just a small portion from the main drain.

I moved the handle so that it was mostly or all Main Drain, and as I did, the pump began struggling and I noticed that the pump filter pressure gauge fell to nearly zero which to me indicated that there was very little flow. The noise from the pump was very loud (the noise of water being churned with air I suppose as it struggled to suck from the main drain). I checked the returns in the pool and there was a small amount of water flow, so that seems to indicate it is not totally plugged. I then moved the valve back to mostly skimmer.

So my question is: Is this normal? I had a pool in the past and I dont ever recall the pump struggling no matter where it was sucking the water from.

Second question, the pump is running 24 hours a day. The timer is set to the ON position in the over ride. They told me to just scrub scrub scrub and they will check in on me every few days to test the water balance, but in the meantime I have not been able to reach them.

Hoping someone can help me!!!
 
1. It doesn't sound like it's draining properly. Hopefully it's something simple. Have them back out.
2. Even though they're testing the water you could be doing it independently. Get a recommended test kit.
 
Welcome to the forum. :wave:

As you read further, You will see we are dedicated to self testing. No one cares about your water more than you and, with the support of this forum, you can managed your pool in a sensible way without depending on sketchy input from your builder.

If your main drain is not plugged or restricted, then about the only other possibility is a bad suction leak in the above ground piping from the main drain to the pump. My bet is the main drain has got some junk in it.
 
Welcome to the forum. :wave:

As you read further, You will see we are dedicated to self testing. No one cares about your water more than you and, with the support of this forum, you can managed your pool in a sensible way without depending on sketchy input from your builder.

If your main drain is not plugged or restricted, then about the only other possibility is a bad suction leak in the above ground piping from the main drain to the pump. My bet is the main drain has got some junk in it.


Thanks everyone,

Finally the builder called back and they are going to send someone out to look. I totally agree with me checking it independently and I will.

The pool work turned out very good....very happy....my only complaint has been with communications....very bad!!! The whole process it was like pulling teeth....with an attitude of just let us do our job and quit bugging us. If it were not for that attitude I would have given them an excellent rating. Through the process I had concerns or questions. Sometimes my concerns were not warranted, and that was cleared up with a simple visit or call, but on other occasions I was correct.

Rick
 
Still waiting for them to show up.....brushing the pool each day as instructed. The pool started off 4 days ago nice and clear and blue, now its cloudy most of the day. Obviously something is not right. There is very little intake from the master drain. Im sure the skimmer is not going to clear up the plaster dust on its own. I have a Jandy filter its about 4' tall. The pressure reads 10 when the skimmer is the only operation, and if I switch to Main Drain only, the pressure drops to less than 5. I guess I am wondering what is NORMAL for pressure. I believe the skimmer is working properly, the operation sounds smooth with nothing unusual. Only when I turn it to main drain only does it sound loud and struggling churning so hard it produces air pockets. Interestingly the water seen through the pump plastic REVERSES in its swirling motion. That tells me that the normal swirl from water entering the pump is so low that the impeller motion is now determining the way the water is swirling because of the blockage....if you understand what I am saying.
 
Can you post a pic of the valve? I know when my pool was installed, just looking at valve handles I assumed they were channeled one way, but it was actually the other way. In other words, can you be sure you opened the valve to the main drain, instead of totally closing it off? Modern main drains have very low pull speed due to child safety laws, it can look like its not doing anything. Your filter dropping to 0 pressure sounds to me like you turned the valve and shut off all flow. Maybe that's too simplistic of a possibility but I made that mistake.
 
This may sound crazy, but is the valve suction source mislabeled? I.e., the valve when you switch it to Main Drain is actually switching entirely to skimmer?

the skimmer in our new build isn't suction, it's pressure - in other words, it blows water through a Venturi under the basket which draws water past the weir door and traps the floating material in the skimmer. There's a Venturi outlet right below the skimmer inlet which has a constant outflow when running, and there is no suction going TO the pump from the skimmer with the valve setup about 20% to skim outlet and 80% to in floor cleaning.

if you can post a picture looking down into your skimmer bowl without the basket in place, that might help. Also, not unusual to run 24/7 pump action on high speed after the first startup to ensure circulation and pump motor test/breakin.
 
This may sound crazy, but is the valve suction source mislabeled? I.e., the valve when you switch it to Main Drain is actually switching entirely to skimmer?

the skimmer in our new build isn't suction, it's pressure - in other words, it blows water through a Venturi under the basket which draws water past the weir door and traps the floating material in the skimmer. There's a Venturi outlet right below the skimmer inlet which has a constant outflow when running, and there is no suction going TO the pump from the skimmer with the valve setup about 20% to skim outlet and 80% to in floor cleaning.

if you can post a picture looking down into your skimmer bowl without the basket in place, that might help. Also, not unusual to run 24/7 pump action on high speed after the first startup to ensure circulation and pump motor test/breakin.


Definately the main drain, because when I turn off the SKIMMER it stops skimming with no water flow, so the MAIN DRAIN off position is the one. I also verified it is correct because when I shut of the SKIMMER and then sweep some stuff over top the MAIN DRAINS (2 of them) it will take in a bit of debris so long as you get it right up to the drain.

I am going to upload a VIDEO so you all can see this and tell me what you think.

Despite me asking the pool people to meet with me.....they show on the property, and I just miss them by a few seconds. I noticed the person was out there, then by the time I got off my phone, they were GONE! Never bothered to tell me they were on my property.

I called their office and quized them....and they told me that yes he checked the main drain and it is fine. I really took exception to this because to me it is quite obvious. I also said HEY I had a pool for 10 years at my last home and it never acted like this.

Their response "ours is plumbed differently".

OK....I'm willing to give them the benefit of doubt, but I cant imagine why the pump would struggle so much when the skimmer is off and the main drain is 100% on.

They said they are coming again of Friday to do "pool school" so I said I will take it up with that person when they arrive, but they were quite adamant that this was NORMAL.

If you all dont mind looking at the video and letting me know what you think. I did my best to shoot it in such a way you get to see and hear what is happening when I switch.

You cant see it super clear, but when you see the gauge on the filter......when it is in SKIMMER MODE, the pump is not laboring, and the pressure reads nearly 10. When I switch it to MAIN DRAIN, you will immediately hear the laboring sound of the suction, and the pressure reading on the filter goes down to nearly 3 or 4. But I dont know what that indicates.

Maybe I'm worried about nothing but I just paid a small fortune for this pool and I want to be sure it is working properly.

VIDEO IS HERE: https://youtu.be/JQ32PqnW6jo

Thanks
 
When you play the video, I first have the valve in the position where both the Skimmer and Main Drain are on. They told me to leave it where it is, which is a little more main drain then skimmer. At this point there is no real suction noise because the skimmer is nearly wide open. Next thing in the video I turn the MAIN DRAIN complete off, and again you see no real difference in the noise, and the filter pressure gauge reads about the same. I then place the valve in the position where the SKIMMER is completely OFF and now you will hear all the noise as if it is struggling. The water in the viewing window of the pump is being all churned up with air pockets and you can clearly hear the loud noise. The water swirling is also completely reverse. You then see the filter Pressure gauge drop to about 3.

Again....I confirmed the positions and what they turn off. The valve in the SKIMMER OFF position stops water flow completely from the SKIMMER. The valve in the Main Drain OFF position stops any flow from the Main drain.

There is some flow....no doubt, but very very little. Also.....when I turn the SKIMMER valve to OFF and you hear the struggling....you will also see bubbles come out of the pool returns, and the water flow is not nearly as forceful when it is MAIN DRAIN Only.

Hope this will allow some "Pros" here to either tell me that I am worried about nothing, or give me some ammunition for the Friday visit.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Good video to show the issue. I don't think it's right. It appears that the main drain line has much less flow than the skimmer. I think the builder may have created a problem in the main drain line somehow.
 
Good video to show the issue. I don't think it's right. It appears that the main drain line has much less flow than the skimmer. I think the builder may have created a problem in the main drain line somehow.


I had a pool before and I dont ever recall there being a suction difference between the skimmer and the main drain. This is not a deep pool and the pump is only 30 feet from the main drain compared to at least 45 feet in my previous pool. To me there can only be one reason for the difference in flow, and that is some sort of restriction. I hope this isnt going to be a battle with these guys.
 
I had a pool before and I dont ever recall there being a suction difference between the skimmer and the main drain. This is not a deep pool and the pump is only 30 feet from the main drain compared to at least 45 feet in my previous pool. To me there can only be one reason for the difference in flow, and that is some sort of restriction. I hope this isnt going to be a battle with these guys.

This problem has been resolved. The pool company came and changed the pipe between the pump and the valves. They also put "eyeballs" on the pool outlets and this has solved the issue. They explained to me that this is a high velocity pump and the pipe was too small and it was creating back pressure, and that the "eyeballs" needed to go on to provide a little pressure. It was all sort of mumbo jumbo to me, but the pump operates the same now in both the skimmer and the main drain position, and the jets produce a very powerful stream when in the Main Drain position, so I assume everything is good.
 
I have a new install going on. I have a builder just like yours. If questions are asked he said the same thing. " Just let us do our job". Were just at the rebar stage waiting for gunite. But the communication gap is dragging me down. That's when and if he shows up. I asked about my paver's and told him I would like the T pattern. But he said it will be the basket pattern. But when I was in the contracting stage he took me to another install to show me the paver's and they have the T pattern. I'm happy for the company to keep people employed but why a new one every day. Yes their all sub contractors. I will be watching the drains and really like the video to see if I have a problem down the road. Thank you so much for posting the video.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.