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Vinyl Pool Return Leaks

Leaking vinyl pool return There are a number of ways in which a vinyl pool return jet can begin to leak. Once you have worked in the vinyl pool industry for a while you can start to recognize the most common reasons why you might be losing water from your return. The return itself, or the gaskets specifically, are often not installed correctly which means it can be leaking from the day that it is first installed. Leaks can develop over time in returns for a variety of reasons however most of these will have telltale signs...assuming you know what to look for. If you suspect that you have a return (or returns) in your vinyl pool that might be losing water then this page will help you to figure out if they are leaking, and if they are, how you should go about fixing them.


The gasket and flange system used for vinyl pool returns have a few known failures that you will encounter commonly in the field. The first and most obvious would be any time where there are screws missing from the return flange, or the screws that are there are not tight or are stripped. Another common leak would be from failing flanges that have started to crack either from strain or from chemical damage due to poor water chemistry in the pool. Leaks around vinyl liners from stretched or displaced vinyl, usually as a result of the pool being drained, is very common to see in vinyl pools. Finally, leaks on the back side of the wall are unfortunately extremely common in vinyl pools. These will be the hardest to locate since you will have no way of seeing them directly - only the symptoms that return leaks on the back side of the wall leave.





Gasket Orientation For Vinyl Pool Returns



Many of the problems relating to leaking vinyl pool returns is directly as a result of the gasket and flange orientation not being installed correctly. The main problem is that the two most common types of returns, Hayward and Jacuzzi, use a similar but uniquely different system and inexperienced installers often confuse the two.

The end result is that when installed incorrectly the gasket can fail to seal against the flange and begin leaking. Incorrect installation can also result in a short term leak free installation, but one that develops a leak within a few years time. When installed correctly, the gasket and flanges used for vinyl pools should easily last the length of the life of your liner.




Hayward is the more common of the two type of return fittings that you will encounter in the field. This video shows the installation of a Hayward return flange along with the correct gasket orientation. There are many different methods for how to install a return flange and this video is just one example of this.


Some installers prefer to leave screws under the liner for locating the return hole locations however you should not need to do this. It is not hard to feel the holes for the screws through the liner so long as you know what you should be looking for.




In this video you will see the installation of a Jacuzzi style vinyl return fitting which has a slightly different orientation than the Hayward return. If you were to forget to install the second gasket on this return on the pool side of the vinyl liner, similar to how the Hayward return is installed, it is not guaranteed to leak...but it might.


Problems with leaking returns from gasket orientation are much more likely to develop over time with Hayward returns. If you are going to have a problem with a Jacuzzi return leak, it will probably happen right away after installation.


If you suspect a leak in your pool return then unless your liner was just installed then it is not likely to be from gasket orientation. A much more likely scenario is that the flange has failed for one reason or another. Many of these failures would relate directly to a problem with water quality in the pool. The faceplate itself can become weak over time from chemical damage. This can result in stress fractures where each of the screws are located. Also poor water chemistry can have adverse reactions on the gasket material and this can adversely affect the compression tightness of the screws.


Cracks & Spinning Screws On Return Faceplates

The process of finding a leak in a swimming pool starts with a process of elimination to determine the leak location. Since return lines are one of the most common causes for leaks in a pool you will often find yourself at the stage where you suspect the return is leaking, but need to confirm your suspicions somehow. If the leak were in the plumbing line itself, then a pressure test will help you to identify and locate the leak. If your leak is not in the pipe, but instead is in the wall fitting, return jet, flange or gasket, then a pressure test is not going to help you.



If you suspect a leak in your pool returns then you should start by simply doing a visual inspection to see if you can see anything that might indicate a failure. Look for cracks in the return faceplates that start where the screws are located, as this is a common way that return fittings will start leaking.

You also want to take note of the type and condition of the screws that were used to install the return. All four screws should be of the same type, and all four should be in the same condition. If you see that one or more of the screws looks different, or if one or more of the screws look like they are rusting or deteriorating, then this would be a major red flag that would warrant a closer inspection.


When it comes to the screws installed on your returns, at some point you need to check the compression tightness of each screw. Hayward flanges use a plastic receiver, old style Jacuzzi returns use a brass grommet receiver on the wall side of the return fitting and the new style Jacuzzi has a plastic flange similar to the Hayward design. At a glance you should be able to tell the difference by looking at the screw. The old style Jacuzzi screws are much thicker, and have a machine thread as opposed to a coarse thread designed for tapping into the plastic receiver flange. With the old style Jacuzzi screws your concern is that the brass grommet on the back side of the wall might drop off, where with a plastic receiver flange your concern will always be simply stripping the flange from over tightening the screw.


Be warned that if you start to inspect or test your return screws in any way you do run the risk of causing a problem or making a problem worse which you MUST then attend to. You should not attempt to spin screws on your returns, or do anything more than a visual inspection or dye test, unless you are ready to take on any work that might develop from your testing.


Jacuzzi returns are notorious for the brass grommet to break away from the wall flange which results in a situation where you are not able to tighten the screw nor are you able to unthread it from the faceplate. A plastic flange screw stripping out is not good, but a much easier fix than stripping a grommet on an old jacuzzi return (or skimmer) where you can't tighten or remove the screw. Regardless, if you start checking the tightness of each screw, and you accidentally cause one to strip or start spinning, then you have now opened a can of worms. If your return was not leaking before you can count on the fact that it is surely leaking now.



Fixing a spinning screw in a return flange is a real problem for the average pool owner to deal with. An experienced liner installation technician however, would be able to fix this problem without even coming close to breaking a sweat. If you have a Hayward return, then your first repair attempt should be simply to try to install a slightly larger screw. Since the back side of the return flange is made from plastic, more times than not you can tap a larger screw in just by using a screwdriver. So long as the screw pulls the flange tight to the wall, and you are able to tighten the screw without it spinning, then problem solved.


Jacuzzi style returns can have a plastic style flange or a brass style flange with a receiver grommet. You should be easily able to tell by partially removing one screw from the return. The older style is a very thick screw, with a very fine machine thread. Newer style Jacuzzi returns have a smaller, course thread screw. You can also tell what kind of return you have simply by the shape of the faceplate. Hayward return faceplates have rounded edges, where the Jacuzzi style have a more boxy, and angular profile. In the same way the Hayward return screws can potentially be oversized, so can the newer Jacuzzi style with the plastic flange. If over sizing the screw does not work, or if you have the machine thread style Jacuzzi returns, then you will need a more involved repair solution.


When all else fails, the easiest solution to problems with the screws in your returns is to drill new holes on either side of the offending screw. This requires draining down the pool below the return to facilitate using a cordless drill. You want to drill through the faceplate, and right through the wall behind the flange. You do not need to actually tap the wall with a tap. If your screw is just slightly larger than the hole that you have drilled then you will be able to gently coax the screw in by hand with a screwdriver. You do not want to snap the screw, and stainless screws can snap fairly easily, so stop if you can feel the screw binding. You also want to be sure that when the screw bites through the wall, that the flange pulls tight against the wall as opposed to pulling away from the wall as you tighten the screws. If the screw binds, or if the flange pulls away from the wall, simply back the screw out and try again. Once the two new screws are installed you would remove the original offending screw and squeeze some 100% silicone (not epoxy) into the screw hole.


Inspecting The Return For Leaks

So you suspect your return might be leaking, but you have no reason to suspect that the gasket orientation is done incorrectly, and the faceplate itself does not appear to have any cracks. You checked the screws and they at least appear to be very tight, and you could either not tighten them any more, or you were only able to tighten them a tiny amount. There are more ways that your return might be leaking but it is going to get harder to be able to determine this with any level of certainty. As mentioned earlier in this article, if you think the return pipe itself might be leaking, then you will want to conduct a pressure test of the line. This will confirm with certainty if the pipe is leaking, and you will have a chance to locate the leak by listening with a stethoscope or electronic listening devices. If you want to learn more about pressure testing then read this article on swimming pool pressure testing. If you need to learn more about the leak detection process itself, then you can read this article about pool leak detection.


When you plug the pipes to conduct a pressure test, it is sometimes possible that this temporarily plugs the leak at the return. If you consider how the return fitting is installed on the pool, you can see how this can happen. Part of the return flange is installed on the pool side of the wall, and part on the back side of the pool wall. Usually these two parts thread together to sandwich the steel wall of the pool in between. A liner and a flange is added on the pool side, and a pipe is connected on the back side of the pool wall.


incorrent return pipe orientation corrent return pipe orientation


A very common situation with pool returns is that the pipe itself is not installed correctly. This can result in the connection point where the pipe meets the back of the return flange to break due to being a leverage point. If the ground surrounding the pool settles it will move the pipes with it. The pool return being attached to the pool wall will not be able to move at all. This results in the return flange breaking right where it meets the pool wall. Pressure testing of this specific leak location is difficult as the pressure test plugs themselves can block the leak during the test, which would give you the indication that the return pipe is not leaking. It may be leaking from this well known leak location and you will need to do both a visual inspection as well as a dye test to see if you can locate any sign that you are losing water here.



A visual inspection of the inside of your return port is obviously going to be difficult. Usually you will feel inside of the return with your fingers to see if you can locate any obvious cracks. Failing this, you will want to perform a dye test of the return to see if you can detect any dye being pulled actively into the return. Dye tests are seldom conclusive, but this is the final test you can conduct before your only option is to open the deck and dig down to inspect and repair the return fitting. Before you go so far as cutting the deck open you need to be pretty sure that this where the leak is located. If the leak is in the pipe behind the return then you will be able to cut and repair the pipes. If the leak is from the return fitting itself then this is a much more involved repair.


In order to take the return fitting completely off for replacement, you will usually need to replace the liner in the pool. This is an unfortunate reality of return (and skimmer) problems in vinyl liner pools. This is why it is so important to thoroughly inspect vinyl pools and address any potential leaks prior to installing a new liner. I have also seen installers who put a huge, 12" diameter vinyl patch over the whole return location to facilitate changing a cracked return flange on an existing liner. I certainly do not endorse such tactics but if you have a new liner in your pool and have discovered that you need a complete return assembly (or skimmer) replacement then you have very few decent options. By far the best would be to seek out vinyl liner on-site welding services. These people are hard to find, as there are not many of them, but having a mobile vinyl welding and repair company deal with this issue is most likely your best option at this point.


Underwater Camera For Inspecting Pool Returns

Sure if you had an underwater camera / endoscope that you could send into your returns that would make it a lot easier to inspect for cracks and other leaks. It used to be that equipment such as this would be hundreds, if not thousands of dollars, and still can be if you require professional grade equipment. As a pool owner it simply would not make sense to spend this kind of money just to inspect your pool return.




Fortunately the cost of such technology has come down dramatically. As a pool owner you really only need a basic setup to vastly improve your ability to inspect inconvenient and hard to see places like inside your returns. This USB endoscope would make for a VERY handy little tool to have and the cost is low enough that you can easily warrant purchasing it to help inspect your own pool. You would probably find a dozen other reasons around the home to have it also. The only down side is that this might actually allow you to identify cracks in your return fittings or pipe...and then you have to fix it! At least, in most cases, finding a leak in a pool is by far the harder part of most leak repairs. Once you have actually idenified where the failure is, and where the water is escaping, fixing it is the easier of the two tasks...usually. Always be sure to inspect and test vinyl pools thoroughly before installing a new liner. Nobody wants a problem with their returns or skimmers right after a new liner has been hung in the pool.





Swimming Pool Steve

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