Pool Valves: What You Need to Know



The ins and outs of pool plumbing might not be the most exciting topic in the world but understanding the movement of water in your pool’s circulatory system can end up being useful insight. Circulation of water is one of the most important parts of pool maintenance, water sanitation, and for keeping your pool looking and feeling its best.

The best place to dive into pool circulation is with pool valves, which manage the movement of water in your pool. So put on your red jumpsuit, hat, and oversized gloves because today we’re playing Mario and getting to know all about pool valves and pipes.

Pool Valves 101

What are pool valves and what do they do? More importantly, why should you care about any of this?

I’ll tell you why. The circulation of water in your pool is the number one way we keep our pools healthy, clean, and free of debris. If your water didn’t move around then pool filters wouldn’t work, mosquitoes would set up shop, and yard debris would start piling up in your soon-to-be swamp. 

Pool valves keep your pool water moving in the right direction. You wouldn’t want the water going the wrong way through the filter, right? If that happened, you’d have all that filter gunk pushed back into your once-clean swimming pool. 

It’s also a good idea to be aware of the valves that connect your pool equipment together. These pathways are important to familiarize yourself with so you know how each part of the system connects to the others. 

Which valve leads to the pool heater? What about the skimmers and returns? The pool drain? Which valves can be changed and which have only one function? Valves are the gatekeepers of water that move it in and out of your pool while also moving it through your pool accessories so that every component is doing its job to the fullest. 

Getting to Know the Types of Pool Valves

Pool valves come in all shapes and sizes to perform their different operations. In order to better know your pool valves, let’s take a look at the variety of types you might encounter. 

The four big ones to be aware of are:

  • Multiport Valves
  • Diverter Valves
  • Check Valves
  • Valve Actuators

Multiport Valves

When starting your pool valve scavenger hunt, the first place to search for a multiport valve is on the pool filter. This type of valve allows you to do a multitude of things (get it?) such as backwash the filter, filter the pool water, or get rid of water from your pool on “waste” mode when you’re manually vacuuming your pool.

Multiport valves also offer an option to keep your pool water circulating without filtering it too. But why would you want to do that? When using a flocculant, of course. Flocculants are used to clear cloudy pool water and need to be moved around your pool without being filtered out. 

If all of those functions weren’t enough, multiport valves actually have a winter setting too! If you live in a chilly place that freezes in the winter, then the fear of freezing water in your lines always looms large. This setting blocks off those lines so that water can’t get in there and damage your equipment during the winter.

Diverter Valves

The technical term for these are Butterfly valves because they can flap open and closed. No, there’s not a lepidopterarium (it’s a real word) or butterfly sanctuary, in the valve. Think of it as a big flap. When it’s closed, the flap completely blocks the pipe and stops all the water flow. 

As you open it, the flap shifts sideways and unblocks the pipe. Pretty easy right?

That’s a 2-way valve that you’ve probably seen by your own pool system. They usually have a big lever on top that you twist open and closed.

There’s also a 3-way flavor of diverter valve. It works the same way, but there is one inlet and two outlets and the flap that blocks the water is a bit more complicated. The 3-way diverter valve can be open and closed stop water completely, allow water through 1 of the 2 outlets, or allow water through both outlets. 

Always go slowly when opening and closing these types of valves. If you slam the valve closed, all the water pressure will hit your valve and could cause damage to your pipes if the pressure is high enough. 

Check Valves

Check valves, also known as non-return or one-way valves are installed in plumbing to prevent the backflow of water, usually due to gravity. Also, if the pump is turned off, there’s nothing to keep the water from flowing the wrong way. This could lead to some nasty situations ending up in your pool. To protect your sparkly, clean pool from this terrible end — we have check valves.

Depending on the type of pool equipment you use, you may have a couple of check valves in your system or you may have a dozen. Let’s look at the pool accessories that require the use of these one-way wonders.

Water Features

If you have a fountain, waterfall, aerator, or any other water feature installed in your pool, there are two possible sources for where the water comes from. The first is right from your pool water. If that’s the case, you’re not going to need a check valve for this particular function.

If, however, your water source is a reservoir, you’ll need to add a check valve to keep the water from draining into the pool when the feature is turned off. 

Automatic Chlorinators

The term ‘automatic chlorinator’ encompasses things like salt chlorine generators as well. These devices chlorinate your pool as the last stop the water makes as it moves through your filtration and circulation system, pumping super-concentrated chlorine into the water at the last second to sanitize your pool. 

If your pool has one of these, you’ll definitely need to add a check valve as the last stop on the chlorinator express. Think about the chaos that would ensue if that highly-chlorinated water accidentally flowed back into your pool equipment, rather than your pool. Catastrophe, right?

Your pool filter, heater, and other accessories were not meant to handle that kind of heavy dose of chlorine. This is where check valves really shine. They are the last bastion of protection against rebellious water that may try to flow in the wrong direction. 

Solar Heaters

Feel free to skip over this part if you have a regular heat pump or pool heater since those use diverter valves, which we’ve already talked about. Solar pool heaters, however, really need check valves in order to function.

Solar pool heaters work by warming the pool water in the toasty rays of the sun, usually positioned on your roof for optimum coverage. When your pump is turned off, though, all of that water is just going to go splashing back down thanks to the laws of physics. A check valve will stop this backflow from happening and keep the water on your roof where it needs to be.

Valve Actuators

Phew! As you can see there are a lot of moving parts going on here. From automatic chlorinators to pool heaters to water features, there are a lot of automated devices powering your pool. It stands to reason then, that your valves could be automated too!

Why spend half your day walking from pipe to pipe, twisting levers and opening and closing valves when you could set it and forget it? That’s right, it can be done with little contraptions called valve actuators. The future is here today.

Once you’ve installed the valve actuators where you need them to go, these can be wired to a pool control box with a panel of buttons. Now, when you want to divert water or turn on your waterfall, all you have to do is push a button.

If only the ancient Roman baths had had these handy little gadgets. (I bet they’d be pretty jealous.)

When to Replace a Pool Valve

Pool valves, like any other type of pool equipment, do not last forever. If your pool is getting up there in years, it may be time to start replacing those worn out parts. 

Now that you’ve discovered the importance of pool valves to your system’s internal plumbing, you can start checking your valves periodically and replacing them when they’ve grown old, brittle, or worn.

The More You Know About Ebb and Flow

There you have it! You are no longer a pool valve novice. You’ve graduated to pool valve authority and can tell everyone about your newfound knowledge at your next poolside barbeque. 

It’s amazing how such small, seemingly insignificant plumbing components can have such a dramatic effect on the health and functioning of your pool. Now that you know, you can keep an eye on all of your valves and replace the worn-out ones when the time comes. 

Categories: Pool Care, Pool Maintenance