Main Drain Box in Deep End of pool - but no drain pipe to pump input

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
My pool has a drain box on the bottom of the deep end of my pool.

There are three inputs through J-valves to my pump.
1. spa drain
2. skimmer
3. pool vacuum
All three of these work, and are definitely labeled correctly.

But No Pool drain!

What are the chances that:
1. no pipe was ever attached to the drain at the bottom of the pool?
2. somewhere along the drain pipe they capped it off instead of connecting it to the pump input?

Thanks for any thoughts...

Tom
 

pooldv

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The bottom drain is probably plumbed into the skimmer. There should be two holes under the basket. The one away from the pool goes to the pump. The one nearer the pool is either plugged or plumbed to the bottom drain.
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
The bottom drain is probably plumbed into the skimmer. There should be two holes under the basket. The one away from the pool goes to the pump. The one nearer the pool is either plugged or plumbed to the bottom drain.

Thanks for the reply, but...

If the bottom drain is plumbed to the skimmer, as soon as the water level is below the skimmer the drain pipe will be sucking air. How would this allow the pool to drain until empty?

Tom
 

JohnT

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Thanks for the reply, but...

If the bottom drain is plumbed to the skimmer, as soon as the water level is below the skimmer the drain pipe will be sucking air. How would this allow the pool to drain until empty?

Tom

It doesn't. The term drain is a misnomer as it has little to do with draining the pool. It simply provides circulation to the bottom of the deep end.
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
It doesn't. The term drain is a misnomer as it has little to do with draining the pool. It simply provides circulation to the bottom of the deep end.

Thanks JohnT,

Does the fact that I have TWO pipes in the skimmer box prove that the second pipe is the bottom pool drain?

Also, from the spa drain I have one pipe that goes all the way to the pump inlet, and a SECOND PIPE from I don't know where, that is spliced into this spa drain pipe about 10' feet from the pump. What is the origin of this pipe?

Any idea as to the best way to EMPTY my pool, other calling a truck?

Thanks for any info,

Tom
 

JohnT

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Best way to empty it is not to do it unless absolutely required for repair. Many things can go wrong, and most are expensive to fix.

If you need to, use a portable pump to empty the pool.
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
Thanks JohnT,

CAN ANYONE ANSWER THESE TWO QUESTIONS:

  1. Does the fact that I have TWO pipes in the skimmer box prove that the second pipe is the bottom pool drain?
  2. From the spa drain I have one pipe that goes all the way to the pump inlet, and a SECOND PIPE from I don't know where, that is spliced into this spa drain pipe about 10' feet from the pump. What is the origin of this pipe?

Thanks for any answers,

Tom
 

pooldv

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Yes, if the pipe in the skimmer closest to the pool is not plugged then it is plumbed to the bottom drain. No idea on the second question.
 

mas985

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#2 Could be a vacuum release for the spa. Do you have an open ended pipe anywhere near there (not air pipe for venturis).
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
Yes, if the pipe in the skimmer closest to the pool is not plugged then it is plumbed to the bottom drain. No idea on the second question.

Thanks PoolDV,

And just to be 100% certain, when you say "not plugged" you are referring to it having some kind of a physical plug or cap, and not to a blockage by debris?

Tom
 

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TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
#2 Could be a vacuum release for the spa. Do you have an open ended pipe anywhere near there (not air pipe for venturis).

Thanks for the reply mas985,

Yes, right next to the spa there is a 1 1/2" vertical pipe with an open-ended "T" fitting. I thought that was a pressure relief for the pump that blows bubbles into the water jets inside the spa. Apparently, I was wrong...again. :confused:

If the pipe from the vertical open-ended spa pipe is spliced into the spa return pipe wouldn't it just allow air into this pipe which goes to the pump input whenever I drain the spa?

Also, the splice between the spa return pipe and the unknown pipe occurs about 25' from the spa and only about 10' from the pump. Couldn't it be spliced/connected right at the spa rather than running it so far from the pool first?

Thanks for any info,

Tom
 

mas985

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There may be two air pipes. One will make noise (sucking air) when the spa jets are turned on. The other would be a vacuum release that would be attached to the suction pipe from the MD. Do you have one or two air pipes? A blower may be on the second air pipe.

If the pipe from the vertical open-ended spa pipe is spliced into the spa return pipe wouldn't it just allow air into this pipe which goes to the pump input whenever I drain the spa?
Do you mean suction pipe? The return pipe would be the water that travels from the pump back to the spa jets (returning water to the spa). If that pipe is a vacuum release and if you were to drain the spa, eventually air would enter the pipe but it is hard say at what level that may happen. If there is very little head loss from the spa to that vent pipe, then you could possible empty the spa before the vent pipe allows in air. Have you tried this before?


Also, the splice between the spa return pipe and the unknown pipe occurs about 25' from the spa and only about 10' from the pump. Couldn't it be spliced/connected right at the spa rather than running it so far from the pool first?
Yes, you are better of having the splice closer to the spa so it doesn't drain accidentally.
 

pooldv

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Yes, not plugged means that there is not a plug screwed into the hole in the bottom of the skimmer.
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
Thanks for the info mas985!

There may be two air pipes. One will make noise (sucking air) when the spa jets are turned on. The other would be a vacuum release that would be attached to the suction pipe from the MD. Do you have one or two air pipes? A blower may be on the second air pipe.

1. I have a blower connected to the spa via a 2" pipe (the other 8 pipes are 1 1/2") that disappears under the pool.

2. A vertical pipe with an open "T" fitting is located right next to the spa.

3. On the suction side of the pump I have a spa drain.

4. Spliced into the pipe from the spa drain to the suction side of the pump, I have a 2" MYSTERY PIPE...

5. On the pressure side of the pump I have a pipe that fills the spa.

6. Also on the pressure side of the pump, I have spa therapy jets.


Do you mean suction pipe?
Yes, I do. I have to watch my terminology...

If that pipe is a vacuum release and if you were to drain the spa, eventually air would enter the pipe but it is hard say at what level that may happen. If there is very little head loss from the spa to that vent pipe, then you could possible empty the spa before the vent pipe allows in air. Have you tried this before?

I don't think I'm following what you're saying, but when I open the spa drain valve the spa completely empties, and I then hear air entering through the drain at the bottom of the spa. Of course I always plan to stop the pump just before this occurs, but sometimes I don't quite catch it before it 'gurgles.'

Tom
 

mas985

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So is #2 the same pipe as #4? Since it is close to the spa, I suspect not. That is the one that I thought could be a suction release pipe.

Does the #2 pipe make any air sucking noises when the spa jets are turned on?
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
So is #2 the same pipe as #4? Since it is close to the spa, I suspect not. That is the one that I thought could be a suction release pipe.
At the moment, I have no idea. I'm trying to figure out a way to find out. Any ideas GREATLY appreciated...

Does the #2 pipe make any air sucking noises when the spa jets are turned on?
I don't think so, but if so, it isn't much.

Thanks,

Tom
 

JoelFitz

In The Industry
Dec 18, 2014
134
Houston, Texas
My company caps the second hole in the skimmer so the best way to tell if the main drain is plumbed into the skimmer would be to hold the weir door shut and allow the skimmer to empty. If you have water coming up from the second hole it's from the main drain. No weir door? just block the skimmer throat with a towel or pool noodle.
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
I just tried stuffing the garden hose into the open-ended "T" fitting on the top of the vertical pipe next to the spa. The water pours out the therapy jets immediately. I don't know if it reveals anything about the "Mystery Pipe", but the "T" is definitely connected to the jets...

Tom
 

TANEAL1

Active member
Aug 3, 2015
35
Orlando/Florida
My company caps the second hole in the skimmer so the best way to tell if the main drain is plumbed into the skimmer would be to hold the weir door shut and allow the skimmer to empty. If you have water coming up from the second hole it's from the main drain. No weir door? just block the skimmer throat with a towel or pool noodle.

JoelFitz, thanks for the reply...

When I do that the skimmer empties immediately, and loudly sucks air. I'm assuming that water is only pulled from the pool drain pipe inside the skimmer by the flow of water over it from the pool that is sucked into the skimmer inlet. Wouldn't any flow from the pool drain pipe stop when the last of the water is pulled out of the skimmer?

At any rate, I've wondered for years what this second pipe was supposedly to do. As far as I could tell no water was going into, or coming out of, this second pipe.

Tom
 

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