Replacing pool pump - where do I cut old plumbing?

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LoneStarPool

LoneStarPool

Active member
Feb 12, 2025
34
Austin, TX
Pool Size
10000
Surface
Plaster
Chlorine
Liquid Chlorine
I'm replacing my old pump with a variable speed pump to save on electricity costs. I'm new to pool plumbing, but from what I gathered watching a few videos, everything is glued together and people usually just cut pipes and add couplings when replacing equipment. The problem with my setup is that I'm pretty sure it's been done already in the past, so I don't really have much room to cut anything. Here's a picture of my existing setup, with the new pump placed on the side. The inlet is on the same height as the existing pump, so I will be able to keep it on the slap, but the outlet is further back, so I will need to move the vertical pipe a few inches towards the back:
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My questions is, where should I cut (or perhaps unglue?) old pipes in order to make new connections? I'm posting my current plan below. The pipes are 2.5" ID. I want to cut at the marked locations and then glue an elbow at the top cut and a coupling at the bottom cut. Is that the right approach here, or should I attempt ungluing an old connection first closer to the pump, and only if that fails, go with the cut approach?
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I also have a question about this little spigot. What's the purpose of it, should I incorporate one in rebuilt version?
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Any help/advice would be appreciated!
 

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Spigot is to drain some water from the pool. Hook up a hose and open it. However you have a waste line on the MPV.

You can cut the pvc input to the pump right at the diverter, then use a "socket saver" (google/youtube search) to cut the remaining pipe out of the diverter, then just glue a new piece leading to the pump.

Get new high temp unions for the pump.

Your cut for the pump --> filter line is just fine. Get another union for the MPV.

Proper unions should have an oring where it threads into the pump and MPV like this:
1747523990513.png
 
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>> Spigot is to drain some water from the pool. Hook up a hose and open it. However you have a waste line on the MPV.
Do you think there's a point to installing the spigot in the new setup, given I can just use waste setting on the filter valve?

>> You can cut the pvc input to the pump right at the diverter
By diverter do you mean the black 3-way valve (Jandy valve)?

>> then use a "socket saver" (google/youtube search) to cut the remaining pipe out of the diverter
Yes, that would indeed be the ideal solution. How easy is it to screw this up? Are there any other tools/materials I should get to make extracting the old pipe from the 'diverter' easier?

>> Get new high temp unions for the pump
The pump came with the following hardware (2 sets of 2.5" and 3.0" couplings). Should I use this, or should I be getting something else?
1747525546827.jpeg
 
No. Yes. Difficult to screw up, if you get a good socket saver. Nothing else to get. Unions came with the pump are fine, and with that pump appropriate to the pump.
 
So it turns out it's impossible to find 2-1/2 Schedule 40 PVC pipe anywhere near me, they have every other size except for this one (Home Depot doesn't carry it, neither does Lowes). I found one seller on Amazon offering it for $45, but the shipping is like 2 weeks:

I also found one on plumberstock.com, for only $10, but am not sure if it's rated for pool pressure:

2-1/2" PVC Schedule 40 Pipe, White - 5' Length | PlumbersStock

Buy this deal now on the 2-1/2" PVC Schedule 40 Pipe, White - 5' Length from the PlumbersStock store - leaders in home improvement.
www.plumbersstock.com www.plumbersstock.com

Any tips?
 
I tried looking at those, but they're all quite a distance away, and closed till Monday. Let me ask this way - is it safe to assume that if it says Schedule 40, like on the site below, then it's good for pool use?
1747537904667.png
 
LoneStarPool said:
I tried looking at those, but they're all quite a distance away, and closed till Monday. Let me ask this way - is it safe to assume that if it says Schedule 40, like on the site below, then it's good for pool use?
Click to expand...
I cannot answer that question. They do no provide sufficient technical detail. Plumbing house is your best bet. Make sure it is sched. 40 or dual use and pressure rated.
 

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wireform said:
You can also cut the pvc pipe flush with the diverter valve and use a 2.5" coupling on the outside of the black valve body and then just use a reducer bushing (2.5" X 2") in the other end to continue with the 2" pvc.
Click to expand...
Interesting. I didn't even realize I can slip a pipe onto the valve body, rather than inside. Do I even need a coupling? If I can slide a 2.5" pipe over it, I can use the 2.5" adapter the pump came with and go directly from the valve to the pump with the 2.5" ID pipe. I'm assuming I should still ream out the remnants of the 2" pipe from the valve to improve the flow?
 
The issue with slipping a pipe over the diverter and using a reducer is that it it's once and done. The only way you can replumb again is to use a socket saver on the reducer...which will reduce the length of pipe from the diverter.

With a pipe IN the diverter, you allow for the use of a socket saver again in the future. YMMV.

I'd always bias towards not having to replace the diverter (using pipe over the diverter) vs. being able to socket saver and not have to replace the diverter.
 
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LoneStarPool said:
Interesting. I didn't even realize I can slip a pipe onto the valve body, rather than inside. Do I even need a coupling? If I can slide a 2.5" pipe over it, I can use the 2.5" adapter the pump came with and go directly from the valve to the pump with the 2.5" ID pipe. I'm assuming I should still ream out the remnants of the 2" pipe from the valve to improve the flow?
Click to expand...
Just understand the valve body is 2.5" , equal/same size as 2.5" pipe so you need a coupling as the pipe itself won't slip/fit ontop.
 
PoolStored said:
The issue with slipping a pipe over the diverter and using a reducer is that it it's once and done. The only way you can replumb again is to use a socket saver on the reducer...which will reduce the length of pipe from the diverter.

With a pipe IN the diverter, you allow for the use of a socket saver again in the future. YMMV.

I'd always bias towards not having to replace the diverter (using pipe over the diverter) vs. being able to socket saver and not have to replace the diverter.
Click to expand...

Good point. I guess I can use it as Plan-B if I screw up with the socket saver tool. I just figured slipping the pipe over would improve the flow dramatically since I wouldn't be constricting the flow to 2" at all. I'm looking into ways to save electricity.
 
wireform said:
Agree, but was just making the statement that it's not once and done as there's always the fall back.....
Click to expand...
Fair point, but now I have a franken monster diverter with an overlay, I don't know where to cut the overlay even with the end of the diverter, so I can socket saver. Doesn't seem trouble free. Again, YMMV.
 

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