How To Add a Pool Waste Line


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The best way to drain water out of a pool is through a 1 1/2" waste line. If you have a filter with a multiport valve, you probably have this feature built in as one of the valve mode. But if you have a cartridge filter you may not have this feature and you may be spending hours draining your pool with a garden hose. This guide shows you how to add a valve and 1 1/2" hose to drain your pool.

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Step by Step


Step 1

Before you cut into your pool pipes, make sure your pool pump is shut off. Turn off power to the pool pump at the circuit breaker.

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Step 2

Next you will have to relieve the pressure that has built up in the pool filter. To relieve pressure turn the air relief valve on top of the pool filter counter clockwise. Water will spray out initially as you see the pressure on the pressure gauge go to 0 psi.

Step 3

This is a picture of our current set up. When there is too much water in the pool, we have to purge the water by opening this spigot and draining the water though a garden hose. This process takes hours.

Step 4

To add a larger waste hose we will have to T fitting into a stretch of pipe on the discharge side of the pump. Ideally we will want a place next to a union so that we can remove a section of pipe and provide room to slip in a T fitting. The best place appears to be the section of 2" pipe coming off the heater union.

Step 5

Because we are going from 2" pipe to a standard 1 1/2" hose, you will have to use a 2" to 1 1/2" T fitting.

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Step 6

Loosen the exit union on the heater. If you can't loosen the union nut by hand , you may have to use a strap wrench like the one shown

Step 7

Put the new waste line fittings together and place it where it fits best. Mark the end of the T fitting where it hits the 2" pipe.

Step 8

Measure how far into the T fitting the 2" pipe will slide in and add that amount to the line previously marked. In this case we are adding 1 3/8".

Step 9

Mark the pipe 1 3/8" up from the first mark.

Step 10

Cut off the 2" pipe at your second mark. Try to make this cut as straight as possible.

Step 11

Deburr the edges of the pipe with a rounded file and clean the pipe with a damp rag. This file has two sides, flat and rounded.

Step 12

Adding the T fitting will make the length of pipe going to the union longer so we will have to shorten this pipe. To determine how much to cut off, measure the inside of the T fitting between the two stop ridges. The measurement for this T fitting is 2". Add 1/4" to this to allow for none square cuts. Note: not all T fitting are the same size so measure the T fitting you purchase.

Step 13

Glue the T fitting to the lower end of the 2" pipe. Gluing is a two-step process. First apply a thin but even coat of purple primer on each surface to be joined: the outside of the pipe and the inside of the fitting.

Step 14

After the primer dries, apply a thin even coat of glue to both surfaces.

Step 15

Immediately push the T fitting onto the 2" pipe and twist 1/4 turn to spread the glue. Make sure the T fitting is lined up in the correct direction. It may help to side a 1 1/2" pipe into that side of the fitting to see where it's going before gluing the fitting. Wait 30 seconds for the glue to set.

Step 16

Mark 2 1/4" on the extracted 2" pipe (as measured in Step 12).

Step 17

Cut off the extracted 2" pipe at the 2 1/2" mark. Make the cut as square as possible.

Step 18

Deburr and clean the 2" pipe

Step 19

Slide the loose pipe into the T fitting to check the length of pipe fits to the heater union.

Step 20

Glue the shortened 2" pipe to the T fitting. Before the glue dries (15 secs) make sure the other end of the pipe lines up with the union.

Step 21

Screw on the union nut and hand tighten

Step 22

Cut and deburr a length of 1 1/2" pipe that will get us past the other pipes

Step 23

Glue this pipe to the T fitting.

Step 24

Glue a 1 1/2" ball valve to the other end of this pipe. Be careful not to get glue into the ball joint.

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Step 25

Cut, beburr and then glue a short section of 1 1/2" pipe to the other end of the ball valve.

Step 26

Add an elbow and short pipe as required to redirect the flow of water.

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Step 27

Attach the hose to the waste pipe. You may have to leave the end of the hose in the sun for a while to soften it up so that it stretches enough to attach to the pipe. Wrap the end of the hose to the pipe with duct tape to keep it on. 

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Step 28

Lay the hose out to the driveway.

Step 29

Wait 2 hours for the glue to completely dry.

Step 30

Turn on the pump.

Step 31

Close the relief valve on top of the filter.

Step 32

Open the ball valve.

Step 33

Check that water is flowing freely out of the end of the hose.

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(1 to 8 of 8)

 Posted: 8/29/2020 

Thanks for posting this. I'm in the process of moving the equipment for my above-ground pool from the side of the pool to a dedicated equipment pad, and this is exactly the kind of setup I want to add for the waste line. About ten feet away from my pad site is a gutter drain line that empties out far away from the house, so that will be the perfect place to attach the waste.

InyoPools Product Specialist  Posted: 9/1/2020 

Out of curiosity, why did you decide to move your equipment? Was it an aesthetic choice or just for better drainage?

 Posted: 7/30/2018 

I have a pop–up valve out front for my drainage and a collection bin about 12' from my equipment. As a former pool builder, I can't understand why another builder wouldn't put in a water–line drain in the tile when planning the project! I like your idea for a DE or sand or even cartridge filter if a collection bin isn't within proximity to conceal the subterranean application I propose. My cost to do this may be prohibitive, but I’ll make sure to budget it and get authorization from the boss! Bottom line, I think I’ll be happier with a buried drain than that dang garden hose partially hidden by my St. Augustine grass. Simple solution? Replace the spigot fixture with the seized hose; however, that doesn’t resolve the above ground draining of the pool/spa. Will advise, Will

 Posted: 1/24/2018 

Patrick - It would seem to make more sense to place the waste line before filter. If you are using the waste line to vacuum out debris on the bottom of the pool, you would like to avoid having all this debris going into the filter. However, since the piping is more accessible after the filter, most people insert the waste line there.

 Posted: 1/22/2018 

would you install the wasteline before before filtering the water or after the water has gone through the filter?

InyoPools Product Specialist  Posted: 9/21/2017 

Leo - No, you do not need another shutoff valve. The water will still go through the filter as it goes on to the waste line.

 Posted: 9/20/2017 

Do you need to place another shutoff to keep the water from going through the filter? Or will it just take the path of least resistance?

 Posted: 11/17/2011 

Run your hose to the drain that is locaed normally in the front of your home, that way it drains directly back to the waste water plant vice into the public sewer system.