When to Replace Your Pool Filter O-Ring

Written by Michael Dean
May 5, 2023

pool filter system

What do you do when you notice a leak around the area that houses your filter? Initially, you may start to stress about the cost and time needed to repair it. However, many different things can cause this issue, and not all require a hefty bill or hours of labor.

One common reason for a leak is an issue with the O-ring in your filter. Thankfully, this is a pretty simple fix. Fixing a problem with the O-ring doesn’t cost much and can be knocked out quickly. In this article, let’s explore what an O-ring is, what it does, how to replace it, and more.


Main Takeaways

  • An O-ring is the seal that prevents water from escaping through the filter’s connections.
  • Some signs that your O-ring has gone bad include: a leaking pool filter, a decrease in filter pressure, and a reduced water level in the pool.
  • How often you replace your O-ring will vary from filter to filter.

What Is an O-ring and What Is Its Purpose?

The purpose of the O-ring is to create a seal that prevents liquid from getting through. When it comes to your pool filter, the O-ring keeps the water from escaping through the filter’s connections and entering the mechanism itself. You’ll see that it is made of elastic/rubber material and resembles a large rubber band. You can pick one up at any pool supply store. Here’s one I found at my local Leslie’s store.

Initially, they called this type of ring an “O” ring because of its shape. However, since its inception, there have been a variety of rings with the same purpose. Even though the concept is the same, there are slight variations in the design and manufacturing. The O shape doesn’t always apply, but it is still called an O-ring.

Common Signs That Your O-ring Has Gone Bad

There are two parts to diagnosing a bad O-ring. The first part is recognizing that it’s relatively simple to figure out when the O-ring needs to be replaced. The second part is you will immediately notice something is wrong. This isn’t because of anything catastrophic, but three issues can occur:

  1. Leaking Pool Filter – this might happen when the filter is under pressure or turned off.
  2. Decrease in Filter Pressure – check your filter pressure gauge; any gaps in the filter seal will cause the system to lose pressure.
  3. Reduced Water Level in Pool – especially for above ground pools.

Other signs you can look for include the ring’s appearance, as there may be cuts or breakage in the material. This can happen if the ring hasn’t been adequately maintained and lubricated. Without adequate lubrication, the ring can dry out and crack., which causes the filter to leak.

Additionally, you may be able to tell by the smell. Due to the part being made of an elastic/rubber material and housed within a mechanism that includes a motor, a worn ring can smell like a burning tire.

How Often Should You Replace Your O-ring?

The frequency of replacing your O-ring will vary from filter to filter. It is also specific to the type of O-ring that you utilize. Some pool owners choose to be overly cautious and replace theirs yearly as part of routine maintenance. However, this isn’t necessary by any means. Depending on the type of O-ring, you can go several years without changing them, at times even up to 15. Other O-rings are built to last for the duration of the filter itself. Therefore, it is best to explore the life expectancy of your filter’s O-ring.

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What Steps Should I Take in the Event of a Filter Leak?

In the unfortunate event that you notice a leak in your pool filter, do not immediately jump to the conclusion that you need to replace the O-ring. You can do several things to try to identify the cause of the issue. Some usual suspects are not as labor-intensive as the more severe scenarios. Therefore it is best to start small.

  1. Take a preliminary look at each component of the filter. Make sure the bands are in the correct place and the clamps are tight. Check the bands internally and externally. Additionally, check the O-ring itself is lined up correctly and in its respective spot.
  2. Clean all of the bands, O-ring, and the areas around them. Again, pay attention to both the bands and O-rings inside the filter and outside. Follow up with lubrication and apply an adequate amount.
  3. At this point, if the previous steps haven’t proved successful, you want to consider replacing the O-ring. You can find new O-rings at most hardware or pool supply stores. Make sure that you purchase the correct size for your specific pool filter. Purchasing a size that is too large or small will only increase your frustration. Additionally, buying the wrong size will also prolong the repair.
  4. If you are still experiencing leaks, you may want to check the gasket. It may not be necessary to do a total replacement. You may be able to repair any problem areas with the gasket maker. This can also be purchased in supply stores.

Although pool issues can initially cause a lot of stress and frustration, the repair itself doesn’t have to be. Typically, you can fix minor problems with a thorough inspection and consistent maintenance. O-ring issues usually don’t require a complete unit replacement, but if you have an old filter that needs replacing, read my research on the best sand, DE, and cartridge pool filter systems for recommendations on the best brands based on my testing.

Quite often, people don’t pay as much attention to the small components of a mechanism. The O-ring falls into this category. With all the different parts and pieces of a filter, it’s hard to believe that something as simple as an O-ring would have such power. But in fact, it makes a huge difference in the smooth operation of your pool’s setup. Therefore, be sure to take the time to properly maintain it so that it can keep your pool running when you need it most.

Speaking of maintenance, I have an entire guide on sand filter maintenance tips if you need more help with your filter.

Have any questions? Feel free to drop me a line.

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