Pool Valves Explained: Types, Diagrams, and Common Questions

Pool valves are an important part of learning your pool plumbing system and water circulation. You need to understand all the types of valves in your pool and how to use each one at the right time to divert water throughout your swimming pool and keep water flowing in the right direction.

In this article, I dive into the basics of pool valves, the types of pool valves you need to know, sketch out some diagrams to explain the whole system, and answer some frequently asked questions I get about valves. Let’s get into it.

What Are Pool Valves?

If the plumbing system is the road for your pool’s water to follow, valves are the street signs. Like traffic flows in real life, the plumbing system needs help to keep everything running smoothly.

Circulation for a pool is critical. As many pool owners know, keeping water moving prevents things like mosquitoes and backyard swamps. That’s because pool water needs to get moved around for the filters to do their job. If you aren’t forcing water through the filter, the stuff trapped in the water won’t get removed. It all comes down to that movement.

Pool valves ensure that everything moves in the direction it’s supposed to. Everything in your pool’s plumbing system is meant to work with water flow going a set way. If water starts flowing the opposite way, we can run into problems. Remember those mosquitos and swamps we talked about earlier?

Besides those unwanted headaches, there’s also a concern about backpressure. Having water diverted back in the direction it just came in prevents unfiltered water from getting cleaned. If that goes on for too long, you’ll have worn-out motors and burst pipes to worry about on top of those unwanted visitors.

How a pool valve keeps everything moving correctly depends on what kind of valve it is.

The Different Types of Pool Valves and Features

Different valves have specific ways to direct water, but they all function to keep things going as they’re supposed to. Here are some valves and features you will likely find in your pool.

Multiport Valves

You’ll find a multiport valve on your pool’s filter. A multiport valve’s job is to allow water to flow in many directions, depending on what setting you choose for it.

Earlier, we mentioned that you don’t want water to flow in many directions when your pool is running. That’s still true here! A multiport valve allows you to change the flow’s path depending on your actions.

For example, if you’re using a flocculant to clear up cloudy water, you’d use the multiport valve to direct water away from your filter. That way, the flocculant has a chance to work without getting filtered out first.

You can also direct the flow to do other tasks, such as backwashing your filter, expelling wastewater, or removing water from your pool while manually vacuuming it. Multiport valves also have a winter mode setting to keep water in your pipes from freezing inside mechanisms. That setting prevents damage to them when the weather is cold out.

I linked my complete multiport valve guide above and have another article on repairing and replacing your multiport valve if necessary.

Diverter Valves

Also called butterfly valves, these can completely open or block off a pipe with a flap you control with a top handle. The point is that you can direct water towards or away from one part of your plumbing system. There are two different kinds of diverter valves for pools:

2-Way Diverter Valve

This valve has a handle on top that rotates 90 degrees. You can turn the water flow entirely off, entirely on, or to a partial flow when you turn the handle. These isolate one part of your plumbing system from the rest of your setup.

3-Way Diverter Valve

This valve has a handle that rotates 180 degrees across one input and two outputs. Turning the handle allows you to shut off one of the two outputs or reduce the flow to the two outputs but not isolate anything. For example, you could close off your skimmer or drain with this valve, but not both if they’re connected to a 3-way diverter.

For more, read my article on what is a pool skimmer diverter.

Check Valves

Check valves are one-way streets all the time. Their primary purpose is to keep water from backflowing into places it shouldn’t when you’ve got the pump turned off. Depending on the design of your system, you might have just a few of these valves or over a dozen.

These valves get used in combination with several pieces of equipment and features for your pool. Some of the common ones are listed below.

Automatic Chlorinators

Chlorinators are the last place your plumbing system routes water through before emptying back into the pool. That’s because concentrated chlorine is corrosive and can damage the machinery of your swimming pool pump or pool heater.

A check valve gets installed between the chlorinator and the pump or heater to ensure chlorinated water doesn’t backflow into these machines and damage them. Without a check valve, when you turn off the water flow for the system, this backflow can happen as the water settles inside the pipes.

Water Features

Water features are cool features unique to your pool. These could be a fountain, a waterfall, or an aerator installed in your pool. This water source can be either your pool water or a separate water reservoir.

If the water feature uses pool water, you don’t need a check valve since these features don’t usually backflow into any problematic parts of the plumbing system. Since we’re not worried about backflow here, a check valve isn’t needed.

But, a separate water reservoir means you have to be more careful. This water is on a separate loop, so it might not get chemically treated like your pool water. A check valve prevents backflow from flowing into the pool when everything shuts off.

Spas/Hot Tubs

If you have a spa connected to your pool, you might have noticed the water level in the spa is usually higher than in the pool. This is because a check valve connects the spa to the rest of the plumbing, keeping the spa water separated as best as possible.

If you need to turn off the pump for the spa, you don’t want this water flowing back or fully draining into the pool. This can mess up the pool and spa levels, causing an overflow.

Solar Heating

Solar heating has a unique design feature that makes a check valve important. Solar heating captures sunlight with solar panels to heat your pool. This heat gets transferred to the water inside the pipes, and the water returns to the pool.

Since the most space-efficient place to put solar panels is the roof, that’s where most folks install the panels. However, your roof is above your pool, and water in the pipes would typically flow down to the ground when the pump shuts off.

Installing a check valve between the plumbing and the solar heating system prevents this backflow of water from happening.

Valve Actuators

Many of the parts in your pool’s plumbing system are automated. But, the valves have all been talked about as if you have to operate them manually. While they certainly can be manually adjusted, it’s possible to automate your valve’s functions, too. Valve actuators are the devices that make this possible.

Valve actuators allow you to hook up your valves to the pool’s control box. They install onto diverter valves and react to the controls you input on the control box. With the push of a button, the actuators will turn the valves into the desired position for the command you enter.

This way, if you have to divert water away from one part of the pool, you can do so without opening and closing all the valves yourself. Automation here makes it easier to remember what valves you have to open and close by replacing that need to remember with a button press.

Pool Valve Diagram

A. Heater
B. Filter
C. Pump
D. PTP valve with electric actuator
E. Manual P2 valve
F. PTP valve with electric actuator
G. Manual PTP valves
I. Check valve

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When Should I Adjust a Pool Valve?

Typically, you don’t need to adjust the valves on your pool for regular operation. Valves will get changed when you go to do maintenance or cleaning, but otherwise, stay in a position that best suits your filtering needs for your pool.

You might have to adjust your valves depending on what sort of filter needs you have, though. If you get many leaves and branches in your pool, adjusting your valves to favor your skimmer can help catch that debris. If dirt or similar particles often settle at the bottom of your pool, adjusting your valves to favor the drains can help clear that out faster.

It’s best if you don’t completely shut off your skimmer or drain for long periods. Your pool uses both of these inputs for the plumbing, so favoring one over the other means you aren’t cleaning from all angles like you should be.

When Should I Replace a Pool Valve?

Unfortunately, pool valves wear out over time. As moving parts, general wear will break down the valve’s plastic with time, preventing the valve from functioning. If you worry about when to replace your valves, you can follow a few guidelines.

First, if your pool is getting up there in years, it’s time to check the valves. Shut off the water flowing to that valve and check the valve to see if you can find any broken or brittle ends. Either of those is a reason to replace the valve since broken and brittle parts result in a loss of capability.

Second, you should check your valves when you notice the flow isn’t redirecting the way it should be. If you see leaks when you’ve closed the valve all the way, that could be a sign that the valve isn’t holding up well.

Check your valves every few years to see if they have any wear and tear. If you catch a problem early, that can save you much on repair costs and headaches later.

Putting It All Together

The valves in your pool work to ensure everything flows as it should. Different valves exist to suit different purposes, like single or multiport funneling. Though your valves shouldn’t have to be adjusted regularly, it’s essential to check on them and ensure they’re still strong. Valves are vital to your pool’s health, so the more you know about their function, the better you can ensure your pool works when you need it.

Got valve questions? Drop me a line; always happy to help.

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