My Pool Filter Is Leaking From The Top (We Have a Fix!)

Ossiana Tepfenhart
by Ossiana Tepfenhart

A pool that doesn’t have a filter isn’t a safe one to swim in. However, if you are swimming in a pool that has a malfunctioning filter, then you are still not entirely safe. Even something as innocuous as having a pool filter that’s leaking from the top can be a sign that it’s not good to swim in your pool. Before you dip your toes in, make sure you fix that leak!

There are several reasons why a pool filter could be leaking from the top. The most common issues that make a pool filter top leak include:

  • Cracks Near The Top Of The Filter
  • High Filter Pressure
  • Loose Cover Rings
  • A Bad Assembly

A leaky pool filter that has water oozing out of the top of the cover might seem like it’s no big deal, but it actually can be a hazard. Our guide will help you troubleshoot this in a pinch.

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Before You Begin: Is This Something You Can Do On Your Own?

In many cases, you should be able to fix this without too much of an issue. However, we all know what it feels like to be overwhelmed with your repairs. If at any point you can’t find the source of the leak, call a repairman. It might be something that’s more worrisome than what we cover here.

How Bad Of An Issue Is This?

A pool filter that is leaking from the top is a problem that can have an exceptionally wide range of causes. Sometimes, it’s a matter of a filter that has been cracked from something hitting it. Other times, it could just be that you need to replace the sand. For most issues, having your pool filter leaking will not be a sign that you need it to be replaced.

High filter pressure, loose cover rings, and poor installation can all be fixed by yourself or through a call to your local pool maintenance company. However, there is a small chance that you may still need to get your pool filter replaced. If your leak is minor, then you shouldn’t jump to conclusions in terms of replacement.

Troubleshooting Your Leaky Pool Filter

Now that we’ve explained the basics of what you should expect with your repairs, we decided to break it down by the biggest issues that could be causing this. Let’s take a look at each one.

A Bad Assembly

If your pool filter is brand new, then the most likely culprit is that it was not put together correctly when it was installed. In most cases, this may require a call to the repairman or a quick refitting. In some cases, you might need some new fittings or connections to make the leaking stop. Either way, this should not be a common issue in older models.

Cracks Near The Top Of The Filter

This is another issue that could be cause for a leak, and diagnosing it doesn’t even require you to open up the filter. Take a look at the top of the filter. Do you see a crack or a source of the water leakage? In many cases, a crack in the shell of the filter could cause the leak. Sadly, large cracks in the main body of the filter usually means you will have to replace the filter body in its entirety.

There is some (kind of) good news that you should be aware of if you have a crack at the top of the filter. If you find that your pool filter cracked after a severe storm, it could be related to an impact blow caused by flying debris. Should this occur, you might be able to file a claim with your homeowner’s insurance company to cover the costs of a pool filter replacement.

High Filter Pressure

This is actually a majorly risky issue that might cause your filter to burst or shatter if you aren’t quick to fix the issue. To troubleshoot this, do the following:

  • Turn off the filter. You should never try to fix a filter that’s running.
  • Check the pressure gauge. If it didn’t go to zero when the filter was shut off, you have a bad pressure gauge and need to call a repairman to have this replaced. This could cause your filter to increase its pressure needlessly.
  • CAREFULLY open the filter and take a close look at the sand. If the sand appears gunky, oily, or grimy, then this is the cause of your leakage. Your sand needs to be replaced because it has too much “gunk” in there. If you have no sand in your pool filter, this doesn’t apply. Just check the cartridge to see if you need to replace it.
  • Also, check to make sure you don’t have too much sand in there. If you have no sand in your pool filter, this doesn’t apply. Your pool filter should only be filled 2/3 of the way up with sand.
  • Then, you may need to check the piping in your filter. Disconnect the water filter and take a look at all the pipes that connect to it. Remove any clogs that you might see.
  • Continue by checking the piping that leads to the filter and from it. Sometimes, the clog is here instead.
  • Finally, check the multiport valve. In a lot of cases, this valve will regurgitate water, making it hard for water to leave the filter. Water ends up building up, which in turn, causes a higher pressure.

Note: If your filter is still showing signs of high pressure and you can’t figure out why your filter is leaking after the end of our tutorial, call a professional.

Loose Cover Rings And Fittings

Your pool filter is held together by cover rings and similar fittings. If you notice your filter leaking heavily, then you may need to replace the o-rings that help keep your cover on. To make sure that your filter is properly tightened and fit together, do the following:

  • Remove and replace any o-rings or connectors that are rusty, cracked, or otherwise worn out. In most cases, the cracks or wear and tear are what cause the leaks. It makes your filter less watertight.
  • If your o-rings are still okay, give them a nice cleaning. You should clean them with a rag sprayed with all purpose cleaner. Then, lubricate them so that they remain watertight.
  • Tighten down clamp bands. These should never be loose, really. You can’t actually overtighten them.
  • Check the bolts in and around the top of the filter. If your bolts have started to rust, then you might need to get new bolts for your filter.
  • Look to see if the PVC has warped. Frequent temperature changes can cause the PVC around the filter to warp. If this occurs, you might have to change out the PVC piping before you can use your filter.
  • Check any unions or couplings near the top of the filter. Unions and couplings can both start to leak if they are very worn out.

What To Do If All Else Fails

If you have run through all the different causes of a top leak without any good results, call a repairman. Chances are that there may be a clog that you can’t see. While it’s not ideal, this may also be a sign that it’s time to replace your pool filter. This is especially true if it’s more than six years old.

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Related Questions

How can you tell if your pool filter is leaking?

If your pool filter is leaking, you will probably begin to hear the sound of dripping water coming from the filter itself. You may also notice a puddle of water forming around the area where the filter is located. If the filter is located above ground, you might also notice the water dripping down the filter from the source of the leak.

How do you fix a crack in a pool filter?

Larger cracks generally should not be fixed. They signal that it’s time to replace the pool filter or call a professional for assistance. If you have a small crack in your pool filter, you can usually use a waterproofing epoxy or caulk to fix it. Even if you do fix your pool filter’s crack, you should make a point of saving up for a new filter.It’s worth noting that fixing a crack in a pool filter is almost always a temporary fix. This is a major issue that should not be treated lightly. To ensure that you manage to keep your filter for as long as possible, keep an eye on it and add touch-ups when needed.

How long can an indoor pool filter last?

If your pool filter is away from direct sunlight, it should last for at least 10 to 12 years with proper maintenance. Heavy sunlight can cause your filter to warp and change, which means that you should expect to replace it earlier. At a bare minimum, you should expect your filter to last for seven years in rougher conditions.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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