How to Unclog a Blocked Pool Return Jet (eyeball)

If you notice a decrease in pressure from one or more of your pool return jets (aka eyeballs) you could have a blockage that’s restricting the flow of water back into your pool from the filter. We will cover some of the main causes and how to correct them in this article.

Here’s the short answer…

Sometimes jets get debris in them which blocks and clogs them. If you suspect a blockage, unscrew the jet, now use long pliers or a long screwdriver to dislodge the blockage. There are many other causes for return jets not working including incorrect aim, dirty filter, blocked skimmer or pump.

Now here’s the long answer on how to troubleshoot your blocked-up pool return jet.

Aiming swimming pool jets or nozzles too high creates bubbles and should be avoided.
Swimming pool return jet

What Causes a Blockage in a Return Jet?

Since a pool filtration system is a closed system, water has to flow into your pump from your pool and back out to your pool again and anything that introduces back pressure or constricts suction pressure can be called a blockage.

Through the process of elimination, you can easily determine where the problem is and determine the best course of action to get your water flowing smoothly once again.

Let’s have a look at some of the top reasons for return jet blockage, how to fix them, and some tips to prevent them from occurring in the first place.

Top Reasons for Blockages:

The most common causes of low return pressure or blockages of return flow are related to:

  • Debris in the skimmer basket(s) or pump strainer
  • Dirty filter and/or filter media

Although the skimmer and pump baskets are upstream of the pressure side of your system, they can still be considered blockages. Have a look at our other article on other reasons why your return jets may not be working.

Suction Side Blockages

It’s important to note that a sign that you have a suction side blockage is that you will see low pressure on your filter gauge and you will also notice that all of the return jets have low pressure.

A blockage here will occur in the skimmer line however it could impact the pressure in the return jet. Here’s a full article on unblocking skimmer lines: How to Unclog a Blocked Pool Skimmer Line

1. Skimmer Basket Blockage

This is the easiest of all to fix, simply empty your skimmer basket(s) and make sure that there isn’t a restriction in the suction pipe that your basket sits on top of.

Also, check to see that there isn’t any undissolved chemical that could be blocking the pipe. This is especially important when the water is cool as chemicals tend to dissolve much more slowly than during the summer when the water is warmer.

If you have an obstruction that you can see, simply take a pair of pliers, industrial tweezers, or a wet/dry vacuum and work the obstruction out or vacuum it out.

clogged-pool-filter
Skimmer basket with debris causing blockage

2. Pump Basket Blockage

This is the second stop on your troubleshooting journey, and again it’s a very easy one to do.

Power off your pump and remove the lid to access the pump basket. Remove your basket and do the same steps you did with the skimmer basket.

While you are working on the pump basket, go ahead and switch the breaker off to your pump so that it cannot accidentally be powered on. 

Either use your fingers or a clothes hanger hook (bend the hanger to form a 1.5-inch hook on the end and bend slightly so that you can guide it through the pump to hook any lodged debris).

*NOTE – Make sure you turn off the power to the pump so that it can’t accidentally start while you have your fingers or a tool in the impeller.

Pressure Side Blockages

Now that you have checked the suction side, it’s time to check the pressure side of the water flow where the water flows out of your pump and through the filter and return lines back into your pool.

1. Debris in the Return Eyeball

This is probably the easiest one to fix and is easy to identify if you only have 1 jet with low pressure. Simply unscrew the eyeball and feel for rocks or other leftover construction debris that could be lodged in the pipe and then remove with a long pair of tweezers or pliers.

2. Incorrect Eyeball Positioning

OK, maybe this is the easiest one. If the eyeball gets turned too far in any one direction it can restrict the water flow and you would simply unscrew the fitting and reposition the eyeball so that it points in the same direction as the others.

3. Dirty Filter

If you observe that you have high pressure on your filter gauge and low flow from your jets then chances are you need to clean your filter and check for blockages in your lines leading out of your filter and back to the pool. This can be done by backwashing DE and sand, removing cartridges from cartridge filters, and cleaning with a water hose.

4. Too Many Water Features or Equipment

Water features or the addition of new equipment such as a heater or saltwater chlorine generator can cause issues with return jets.

Although it may not sound like this is a blockage, it kind of is.

The addition of additional equipment or features after your pump and system was sized for your pool could restrict the flow of water back through your jets and increase the back pressure enough to reduce the flow by modifying the original hydraulic dynamic. 

If you have this situation it’s best to call a pool service to come to take a look as you may need to modify your system to accommodate the new setup. You may need to install a booster pump.

Extra reading: Do You Need  Booster Pump?

5. Diverter Valve Blockage

Although not too hard and less likely to be the cause, this can be a little tricky if you aren’t comfortable with working on your own equipment.

Sometimes rocks/plaster or other debris can make their way through the pump and filter all the way into your valves and cause a blockage. A quick disassemble, visual inspection and cleaning can take care of this one.

6. Clogged Heater Lines

Not as common, but sometimes there could be a restriction in the heater plumbing that can reduce the pressure back to the return jets.

If this is the case you will see an increase in your filter pressure as well and this is another time when you may want to call a professional if all else has failed to resolve your issue.

Tips and Tricks to Unclog a Blocked Pool Return Jet

The first tip is to think about your specific situation and what you are observing. If you have only a few jets that are low on pressure then that is a sign that your clog isn’t in a location that impacts all of the jets and you can start to narrow your search.

If you observe that it only happens in the spa or in the main pool then start at the restrictor valves and inspect those to see if you have something lodged in the valve or the pipe.

Or, someone may have simply turned a valve so first double-check that they are set properly and water flow isn’t diverted to one more than it normally is.

If you observe that flow is restricted with only one return jet then shout hurray and know that your fix is likely pretty easy!

Simply check to see that the eyeball is pointed in the correct direction and not turned inward too far, and if it looks good then remove the fitting and start looking for what’s blocking the flow.

If you find it an obstruction and are unable to remove it then try to break it up with needle-nose pliers, industrial tweezers, or maybe a screwdriver. You may also need to consider blowing it back through the pipe in the other direction with air pressure or use a wet/dry vacuum to try to suck it out.

If you did not find any physical obstructions from debris in your baskets or lines you may have a clogged impeller and you will need to remove the motor from your pump and access the impeller housing and impeller to actually pull apart and clean it.

This is commonly needed if you have pine tree needles or other small things that can slip through your skimmer and pump baskets and get lodged in the impeller. This is another more advanced activity that you may wish to have a pool professional do for you.

Lastly, an ounce of prevention is worth a pound of cure, or in this case, investing a few dollars and a few minutes can save you from hours of troubleshooting and potentially expensive service calls.

Here are some of our favorite tips for preventing clogged pool return jets:

1. Skimmer Socks

Using skimmer socks can prevent pine needles and other smaller debris from making their way through to your impeller.

Coopache 30-Pack of Pool Skimmer Socks - Filters Baskets, Skimmers Cleans Debris and Leaves for In-Ground and Above Ground Pools

2. Frequent Cleaning of your Skimmer and Pump Baskets

Keeping your baskets clean is an easy way to keep things from making their way through to your impeller and will increase the life of your pump as well since it will not have to work as hard.

3. Skim your Pool

If you have a heavy debris load it’s a good idea to help your system by removing debris from the water by skimming with a net before it can even get to your skimmer.

4. Replace Old or Broken Baskets

This is a common cause of a single blocked jet. If your pump basket gets brittle and the plastic pieces start breaking, they can make their way into your impeller or pipes then they can easily end up getting stuck in the jet and get lodged. The good news is that’s an easy fix!

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