How To Install a Diverter Valve on the Suction Side of a Pool


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Any pool configuration has two basic piping systems: suction and return. The suction side consists of all the pipes coming from the pool to the pool pump. In a basic system, these include the pipes from the main drain and the skimmers. The return or discharge side consists of all pipes going from the pool pump back to the pool. In a basic system, these include lines to multiple pool jets. On the suction side, you will want to be able to control the flow of water coming from either the skimmers or the main drain. This is done with a diverter valve. This page will provide a step by step process for installing a diverter valve on the suction side of the pump.

Click here to view diverter valves. 

Things You'll Need

Step by Step


Step 1

A 3-way Diverter Valve is assembled at the manufacturer so that the valve operates between the two ports away from the inlet port. In the picture at the left, the valve handle is turned all the way counter-clockwise to stop and close off the left port (skimmers). Water will only flow from the right port (main drain) through to the inlet port going to the pump.

Step 2

In this picture, the valve handle is turned all the way clockwise to stop and close off the right port (main drain). Water will now only flow from the skimmers to the pool pump. In either case, the handle cannot be turned to pass the stops to shut off the inlet port. This is important because if the inlet port is shut off, no water can flow to the pump: the pump will run dry and start to generate dangerous internal pressure.

Step 3

The picture at the left shows the normal operational position for the suction valve. With the handle place halfway between the left and right port, water is allowed to flow freely from both ports through the inlet port to the pool pump.

Click here to view diverter valves. 

Step 4

Some valves like this popular Jandy valve are designed to engage either 1 1/2" or 2" pipe. This picture shows the 1 1/2" pipe option with the pipe slipping into the port opening.

Step 5

This picture shows the 2" pipe option. A 2" coupler slips over the port and the 2" pipe fits into the coupler.

Step 6

When installing a value, you must first remove the internal valve assemble before gluing the valve body to the pipe. This will ensure that you don't accidentally glue the internal valve parts together. To remove the internal valve assembly, first, loosen the lock knob on top of the handle and move the handle halfway between the two upper ports. This will make it easier to pull the assembly out of the valve body. Now remove all 8 screws.

Step 7

Grab the valve handle and pull the valve assembly out of the valve body. You may have to rock the handle a bit to release the assembly.

Click here to view diverter valves. 

Step 8

The next step is to cut the pipe to the length required. Remember when measuring the length of the pipe, allow an extra 3\4 " to 1 1/2 " on each end for the overlap into the fittings (varies by fitting). You can use a regular hacksaw to cut the pipe. Just try to cut the pipe as squarely as possible.

Step 9

When you finish cutting off the pipe, be sure to file off the rough edges on both the outside and inside of the pipe. A file with one side flat and one side rounded works well.

Step 10

Now you are ready to attach the pipe. This is usually a two-step process. First put a thin coat of purple primer on both pieces to be joined: inside the port and the outside of the pipe. Make sure that all joining surfaces are covered and make sure that no primer enters the valve body beyond the ports. After the primer has dried, reapply the two surfaces with Universal CPVC glue. Again make sure that no glue enters the valve body beyond the ports. The CPVC glue and purple primer are usually sold together as a kit.

Step 11

Immediately after applying the glue, insert the pipe as far as possible into the valve port and turn the pipe 1/4 turn to spread the glue evenly. If any glue oozes into the valve body, wipe it out before it dries.

Click here to view diverter valves. 

Step 12

Repeat Steps 8 - 11 to add pipes to the other two ports.

Step 13

To reassemble the valve, make sure that the "INLET" label on the valve assembly lines up with the lower port going to the pool pump. Replace the valve assembly and screw in the 8 screws. Hand tighten.

Step 14

Complete the valve installation by attaching the three pipes coming out of the valve to their suction pipes. You will probably need to add 90-degree elbows to the pipes coming out of the ground from the skimmers and main drain. The picture at the left shows the end result of a typical valve installation for a basic pool.

Click here to view diverter valves. 


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 Posted: 12/27/2017 

Cobus - Many people with long supply lines between the pool and the pump install a check valve in that line to keep water from draining back into the pool when the pump is shut off. For information on check valves, see our guide on "How To Select a Pool Check Valve – Overview”.

 Posted: 12/24/2017 

Hi guys, I am writing from New Zealand. I love your stuff! Question: if the suction line is 17 meters from the pump and it take more than 5 minutes to try and get the pump to prime without any success, is it okay then to install a check valve or any other closed/open valve? I did everything in the book that I know to prime the pump, nothing work. What I see is that water flow out from the ceramic sealbetween pump and motor. MEANING AIR! That must be fixed and before I go that way, I need to know if it will be good to install a valve before the pump as itis along distance from skimmer to pump!

InyoPools Product Specialist  Posted: 6/22/2017 

Kim - I'm not sure I understand your question. If you need to replace the diverter valve on you main drain line and you are asking how to turn off the water to the valve, just turn off the pump. It's the pump that is moving water through the valve.

 Posted: 6/20/2017 

This is great information. My question is that I have to replace the valve for the main drain. My main drain & skimmer are on two separate lines. How can we replace this. Alive with the water flowing? In other words, how can we eliminate the flow of water up to the main drain Valve! Is this possible? Thank you

InyoPools Product Specialist  Posted: 3/31/2017 

anonymous (diverter valve) - Yes. you can replace the inside of a standard diverter valve with a NeverLube Valve Assembly. See our guide on "How To Repair a Diverter Valve". And yes you can use MagicLube to grease the other standard valves.

Anonymous  Posted: 3/30/2017 

I have the gray Jandy valves with the grease cup. The diverter is messed up on one of the valves...the rubber part on the front is stretched out in one corner. Would this cause water to leak or air to get I my system? Are the "never lube" diverters compatible with the existing equipment? I don't want to replace the entire valve, just the inside diverter.

I used Magic Lube with them but it isn't the same as the blue, thicker stuff my installer used. What is the blue stuff and should I use that instead? My pool was built in 2014 so I'm not sure why the installer used this type of Jandy valve vs. the never lube, as I understand that type was out then. Thanks!


InyoPools Product Specialist  Posted: 9/11/2016 

Bill Smith - I think you are referring to the cap on the grease port. This is how you keep the valve greased in some of the older valves. It sounds like the cap needs to be replaced. See our guide on "How To Replace a Broken Grease Fitting On Your Diverter Valve".

 Posted: 9/9/2016 

On the 3 port diverter valve there is a black knob on the front side. What is this for? Mine is real loose and will not tighten up.

 Posted: 6/27/2016 

Yep, that's exactly what happened on mine... Just installed a new VS Pentair Superflo and when I flipped it over to the Cleaner/Vac side, I immediately lost all water flow and the pump changed tones. I instantly turned off the pump and fortunately since I installed a new see thru flo-thru check valve with a union, I was able to take apart both the valve and the check valve section, grabbed a coat hander and bent it so that it would only pull debris through and was able to unblock the line. Works perfect now, tons of suction..

InyoPools Product Specialist  Posted: 5/5/2014 

Paul - It's hard to isolate your problem without seeing the actual valve configuration, but it sounds like the pipe on the right side may be blocked with debris.

 Posted: 5/2/2014 

trying to learn, maybe someone can advise: I have this same set up plus in ground cleaning system. I shut off in ground portion to vacuum bottom of pool via skimmer. Jandy valve was lined up with pump, all okay. 2 pipes one on left and one on right marker as skimmers. I turned Jandy valve to the left to close off left skimmer for max suction for the right skimmer and pump shut down due "pump dry", no water. So I imagine if instead of turning valve to the left I turned it to the right the same thing would happen? Guess I always need to leave Jandy valve handle in pump direction, full open and only shut off in ground cleaning system when I want to use vacuum??????? Please advise. TIA

 Posted: 3/20/2011 

Reading is fundamental. I learned something new today. Did not know at first that the Jandy valve was either or... just saved a bunch of money!!! Thanks a Million!!!