How to Unclog a Blocked Pool Skimmer Line

You might’ve noticed that your pool skimmer has been removing the water a little slower than usual. If you have, your pool skimmer line could be blocked, in which case we’ll show you why this might be as well as ways to fix the issue.

There are several ways you can go about unclogging a skimmer line, such as manipulating your pool’s diverter valve, using a drain cleaning bladder, or using a snake/wire.The most common ways a pool skimmer line can get blocked is through a cracked skimmer basket or by removing the skimmer basket while the pump is still running.

As you can see, there are several ways you can unclog your pool skimmer line. Which one to use is the real question, which is something we’ll focus on in this article.

The pool pump sucks water from the skimmer line.

How Do You Know if Your Pool Skimmer Line is Blocked?

Before actually going about reading through this article and attempting to clear your pool skimmer line, it’s important to understand if the problem is a blockage. Here are some signs you should pay attention to and ways you can identify if the problem you’re having is a blocked skimmer line.

1. Your Pump is Pulsing/Loud

If you’re noticing water surging or pulsing in your pump, you could potentially be dealing with a blocked skimmer line. But first, it’s important to check your pump for blockages and air leaks.

To do this, first, check the O-ring (this article tells you more about how damaged O-rings can cause air leaks and how to fix them) on the pump lid.

Next is to look for blockages in the pump and the pump impeller. The pump impeller is located behind the pump basket, so it’s possible that it could’ve gotten clogged in your pump basket is compromised. In either case, make sure to turn your pump off when checking.

Another potential cause for an air pocket to form is if you’ve just cleaned your pool filter, as removing your filter could’ve caused outside air to enter into the area between the filter and pump.

2. Pump Water Intake is Slow

If you notice that water is slowly reaching your pool pump, that could be a sign that your pool skimmer line is blocked. However, like always, first, check these other potential reasons to rule them out.

First, empty the skimmer basket out. A full skimmer basket can restrict the flow of water. And if you’re using a skimmer sock, if it’s dirty or clogged, remove it or replace it with a new one.

If you’re not sure what a skimmer sock is or if you should get one, check out this article: What is a Pool Skimmer Sock, and Do You Need One?

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Second, check that your skimmer door/weir isn’t stuck as that can reduce the amount of water going through the skimmer.

Finally, be sure that the water level is at its normal level, which is about halfway up the skimmer.

If all of these are normal, it’s most likely that you have a blocked skimmer line.

3. Your Pump is Loud but the Pressure is Low

If your pump is loud, but you’ve noticed the pressure is low, that could indicate that your pump is having difficulty creating a vacuum to pull in water. Again, it’s important to first rule out other potential reasons (such as an air leak or low pool water level) before focusing on your pool skimmer line.

How to Check if the Skimmer Line is Blocked

Since both your skimmer lines (pipes) and main drains direct water flow to the pool pump, you’ll want to know which line has the issue before you decide on unclogging your skimmer line.

To do this, you’ll want to run your pool pump and check each line individually. This is done using your pool’s diverter valve.

Open the main drain valve and note the pump pressure. Then switch off the pump and open the skimmer line only. Switch the pump back on and note the pressure.

If you notice one line that has low pressure or causes your pool pump to lose suction, that specific line has either an air pocket or a blockage.

As a reminder, remember to always leave at least one line open when you’re doing this test, as you don’t want to leave your pool pump running without any water flowing to it.

3 Reasons Why Skimmer Pipes Get Blocked

Before we go on to learn about how to unclog your pool skimmer line, you should understand the potential reasons for your blockage, as knowing the cause can help you avoid such an issue again in the future.

The two most common reasons why your pool skimmer line is blocked are a cracked skimmer basket and removing the skimmer basket while your pump is running.

1. Cracked/Damaged Skimmer Basket

The skimmer basket is there to prevent large pieces of debris, such as leaves, flower petals and the like being sucked into your pump.

It’s important to inspect your skimmer basket every time you empty it. Make sure there are no cracks or gaps in your basket that could allow debris to pass through them.

Regardless of the size of the crack/gap, as long as there’s a way for the debris to escape the skimmer basket, your skimmer line could get clogged up.

Cracked or damaged skimmer basket l Image Credit: Amy Bailey-Lemieux

2. The Skimmer Basket Was Removed With the Pump Running

Another issue you might’ve overlooked is if you removed your skimmer basket while your pump was still running.

If you forget to turn off your pool pump, it’ll continue sucking in water and debris. And usually, when you remove the skimmer basket, leaves and other debris tend to float around in the skimmer.

As such, if you forgot to turn your pump off while you were emptying your skimmer basket, any debris will get sucked into the skimmer suction line. And this could easily clog up your line.

Thus, always remember to turn off your pump while you do your weekly skimmer line cleanup.

3. Buildup of Other Debris

In addition to larger debris, things like hair, small petals, and broken-down leaves can get past the skimmer basket. If you have enough of these they can build up in the pipe causing a blockage.

Sometimes undissolved pool chemicals can cause blockages too. That’s why you shouldn’t add chemicals to the skimmer.

Skimmer basket full of leaves.
Debris, petals, and leaves piling up in the skimmer basket can lead to some getting into the skimmer line.

How to Unclog a Blocked Skimmer Line

There are several ways to unclog your pool skimmer line, but it’s important to use the most appropriate one relative to your blockage, to save you time, money, and any potential damages.

1. Use Your Hands or a Screwdriver

Sometimes the blockage may be at the very start of the pipe in the skimmer. This is usually easy to fix.

Start by turning off your pool pump then remove the skimmer basket. Now poke your fingers into the holes (inlets) at the bottom of your skimmer. Pull out any debris.

You can also use a long screwdriver or a wire coat hanger to try and dislodge debris.

2. Use the Diverter Valve

If your skimmer line has been blocked by common debris like rocks and leaves, you may be able to unblock it using your diverter valve. This will save you from spending money on other tools.

To do this, move your diverter valve back and forth, as that will allow water to alternatively flow from your main drains and skimmer lines to the pump. Each time you move the valve to your skimmer lines, wait a few seconds before moving it back to the main drains.

After doing this a few times, you might be able to dislodge or remove whatever air pocket/debris that might be in your skimmer line into your skimmer basket.

Again, remember to always have at least one line of water flowing into your pump at all times.

3. Use a Drain Cleaning Bladder

If the previous methods haven’t worked, your skimmer line might have a more tightly wedged blockage. You can try using a drain cleaning bladder to clear it out.

A drain cleaning bladder attaches to your garden hose, after which it’s inserted into the clogged line.

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When you turn on the hose, the bladder pushes pressurized water down the line, thus removing the blockage by pushing it into the pump. Just remember to shut off your pump and remove your skimmer basket before inserting the bladder.

4. Use a Drain Snake/Wire

In the rare instance where your skimmer line might’ve been clogged by something denser, you might need to use a drain snake to physically dislodge it.

Snaking is rarely required as, despite it being invaluable when clearing a typical clogged drain, it has several disadvantages when it comes to pools.

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It’s difficult for the drain to negotiate the 90-degree angles of the pool lines. That’s why they’re typically used when pipes are curved or straight.

To use one, turn off the pool pump and take out the skimmer basket. Slowly push the snake into the line turning it as you go. You will probably feel when you hit the blockage. Jiggle it more, then pull it out.

Often it will pull out the stuck debris.

Final Thoughts

Hopefully, you were able to find this guide helpful when it comes to unclogging your pool skimmer line. If neither of these methods works, it might be time to call a professional to help. But before you do that, make sure to give these methods a go and repeat them a few times if necessary, as sometimes these methods will take several tries before they work.

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