How to Set Up Pool Diverter Valves

Written by Michael Dean
May 9, 2023

pool diverter valve and gear icon

Good water circulation helps keep your swimming pool healthy and clean. Pool valves are a simple piece of equipment that allows water flow control to or from a water-filled pool.

Diverter valves, also called butterfly valves, can last decades, but they aren’t indestructible. Eventually, it will be necessary to fix or replace a valve. Follow these instructions, and you will find it’s not difficult to replace a diverter valve yourself.


Main Takeaways

  • Diverter valves are either two-way or three-way, with two-way valves controlling the flow from only one port and the three-way valves are usually connected to the pool drain and the skimmer.
  • You can repair damaged valves if it’s just the internal components that need replacing, but if the valve itself is broken or damaged, you will need to install an entirely new diverter valve.

How Diverter Valves Work

Diverter valves are either two-way valves or three-way valves.

Two-way valves let you control flow to and from one port. By rotating the handle through a 90° arc, a two-way valve can be turned off, on, or anywhere in between. The two-way valve is illustrated on the right side of my diagram above.

Three-way valves are T shaped with one center port and two end ports (the left side of my diagram). It is possible to divert part or all of the water flow from either end port but not from the center port. Rotation of the handle on the side opposite the center port is limited to 180°.

A three-way valve resembles a capital T. The vertically centered pipe connects the pump, and the crossbar is attached to the vertical pipe with the diverter valve. One side typically attaches to the pool drain, and the other to the skimmer.

Repair Considerations

It is possible to repair many damaged pool valves by swapping out the internal components within the body of the diverter valve. There are some instances, however, when the valve itself may break or become damaged. In that case, you will have to install a whole new valve.

It is not unusual for several control valves to be connected, and it may be necessary to replace more than one when replacing the broken one. However, finding a single valve or a valve isolated from the others is possible and simplifies the replacement process.

To avoid costly mistakes, review all of the instructions before starting your project.

Replacing a Diverter Valve

Below is the process that I use to replace a three-way diverter valve.

To start, you need to purchase a replacement diverter for either 1-1/2 inch or 2-inch piping. Many diverters will adapt to either size. Valves are available with paddles coated in Teflon that do not need to be lubricated. In the past, you had to lubricate diverter valves annually, but most modern diverter valves are maintenance-free.

The following are four quality brands of diverter valve replacements.

  • CMP
  • Jandy
  • Waterway
  • Pentair (pictured below)
Pentair 3-Way PVC 1-1/2" Pool And Spa Diverter Valve
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I may earn a commission if you make a purchase, at zero additional cost to you. This in no way impacts my research process or opinions.

You can purchase diverter valves with or without unions. Replacing your diverter valve in the future will be easier if it has unions since you will not have to cut the piping.

Once you have purchased your diverter valve, grab the following items:

  • A PVC pipe
  • Three PVC connectors that are straight
  • A hacksaw
  • A deburring tool, file, or utility knife
  • PVC cement or rain-r-shine PVC cement and purple primer
  • Two daubers
  • Shop rags

Step 1: Turn Off Your Pool Pump

Make sure that you turn off the pool’s pump. As a precaution, trip the pumps off at the breaker.

Step 2: Release Pressure

Release pressure in the lines by turning the safety valve located at the top of the filter in a counterclockwise direction. The filter pressure gauge should read zero.

Step 3: Cut Out Old Piping

During the original installation of your pool’s circulation system, PVC piping and fixtures were probably glued permanently together with PVC cement. To replace the diverter valve in your system, you must first cut the old one out of the piping. Then you can attach the new one with new piping and glue.

Using a hacksaw, cut all the pipes connected to the 3-way diverter valve. Ensure you cut the pipe far enough to fit a short pipe and a connector with a 3/4-inch overlap on each end.

It is best to keep your cuts as straight as possible when you are cutting these pieces. Make sure you use a very sharp blade, but you don’t want to force it. The pressure from pushing the blade edge to cut faster will cause the blade to bend.

Step 4: Smooth Out Your Cuts

All newly cut pipes should have the rough edges filed off. The process of smoothing the cuts is called burring.

Frequently rough edges and stray pipe fragments are left behind after cutting or sawing pipe. Filing or deburring removes shavings or burrs, resulting in a smoother edge. A deburring tool is a special type of file. It features a flat side as well as a round side, but it’s not the only option. A utility knife can also remove shavings or other particles from each pipe.

Step 5: Wipe It Down

When the edges are smooth, use a clean cloth to wipe shavings and dust from the interior of the fixture port.

Step 6: Test the Fit

Dry-fit piping and fittings to ensure they are sized correctly and do not bend or twist.

Step 7: Glue the Connectors

To glue the connectors on each pipe, you will use PVC cement and purple primer. Often sold as a set, you can purchase PVC cement and purple primer at most hardware stores. While there are several types of glue, I typically use medium clear.

When working in a wet environment or where the pipes are constantly draining, you may want to use rain-r-shine PVC cement. It comes in a blue can.

Gluing requires two specific steps to achieve. If you’re bluing CPVC and PVC, you’ll want to start with a primer, which will soften the plastic. This gives it the right adhesion for the cement later on.

  • Apply a thin, even coat of the primer both on the outside of the pipe and the inside of the fixture you’re going to apply it to using a dauber.
  • Allow the primer to dry.
  • Use a different dauber for the cement than you did for the primer.
  • Apply a thin, even coat of cement over the primer. It should go on the end of the pipe and the inside of the fitting as well.
  • Immediately after applying the adhesive, push the connectors together with a twist (quarter turn) to make sure the glue is evenly spread throughout the connection.
  • Allow 30 seconds of holding the pieces together so the glue can set.
  • Wipe the excess cement from the surface with a rag.

Step 8: Trim Your Pipes

Trim three pieces of pipe to be the right size to go between each of the connectors and valve ports. Add 1 ½ inches to the length of two of the pipes to overlay the connector and valve. Cut the third pipe only one inch longer. This will make it easier to fit into the final pipe connection.

Step 9: Smooth Everything Out Again

The three tubes should be smoothed at both ends using the same techniques as in Step 4.

Step 10: Prep Your Diverter Valve

Remove the eight screws holding the new diverter valve cover in place and remove the diverter valve’s internal components. You do this to keep glue from getting on it when gluing in the short pipes.

Step 11: Make Sure Your Diverter Valve Fits

Dry-fit piping and diverter valve to ensure they are sized correctly and do not bend or twist.

If the pipes are too rigid to allow the last short tube to slip into the valve and connector, you may need to use a valve with unions.

Step 12a: Install Diverter Valves Without Unions

Starting with the longer pieces of PVC, affix each piece of pipe to its connector and valve port using the techniques in Step 7. Always follow the two-step method of first using primer and then cement. After applying the primer and glue, insert the tube simultaneously into both the connector and the valve.

After you’ve glued the longer pipes in place, attach the shorter piece, and force the short tube into the system by spreading the piping out a bit.

Step 12b: Install Diverter Valves With Unions

You might want to consider using a diverter valve with unions if the pipes are not flexible enough to force a new valve into the system. Installing it is a very similar process. Follow all of the steps listed above. However, you do not glue the unions into the PVC pipe. You simply screw them into place.

In the future, it will also be easier to change the diverter valve with this arrangement. You can simply replace the valve by unscrewing the three unions.

Step 13: Put It All Back Together

Replace the valve internal components into the valve casing and secure the screws. Ensure that the valve components are placed in the same direction as when it was originally installed. The “INLET” marking should be in the center of the section through which water enters. When the valve is inserted incorrectly, you could shut off the water to the valve.

Step 14: Let It Dry

You must let the glue cure for at least two hours before applying water pressure to the joints.

Word of Caution

Open and close diverter valves slowly. High water press can damage your valve and pipes if the valve is slammed shut.

Need Some Maintenance Help?

Send me a message! I can answer any of your pool maintenance, equipment, or other questions.

Final Words

With all the equipment and devices needed to maintain a pool, it is incredible how a few plastic pieces can significantly impact its performance and health. Don’t underestimate the importance of pool valves to ensure your plumbing works as it should and the water in your swimming pool remains clear and sparkling. For more on the importance of keeping your water moving, head over to my guide on pool water circulation.

Have questions about setting up a new diverter valve? Drop me a line.

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