Leaking Pool Filter Valve

Why Is My Multiport Valve Leaking?

Multiport valves are the main water route interchange for your pool water. If the water needs to be forwarded, reversed or drained out, it will need to be done through this valve. The routing system inside a multiport valve is essentially water’s equivalent to chutes and ladders.

These valves have as many as seven “positions” but for the most part the average pool owner will only use a handful of these.  Here is a list and explanation of the most often used positions so we have a solid footing moving forward: 

  • Filter – The standard operation mode; the water is cycled from the pump through the filter media and back to the pool.
  • Backwash – This selection is the cleaning cycle. The flow of the water is brought in from the pump  then routed to enter the filter reverse to the normal direction. This effectively begins to loosen and eventually eject dirt through the waste port.
  • Rinse – Rinse returns the normal flow of water through the filter but it maintains the exit flow routed to the waste port.  After a backwash some particles may still be left in the pipes so to avoid that dirt being ushered to the pool, we need to rinse.Picture1

The Spider Gasket

If the valve is the highway interchange of your water then the spider gasket would be the guard rail. These gasket spokes act as dividers to ensure the path of the water stays true.  If your multiport valve has a drip coming from the waste port line, most pool technicians will jump for the spider gasket.

The spider gasket is located either on the diverter pinwheel or the base of the valve the diverter faces.  When we select a function on a multiport valve and release the handle, we drop the diverter onto the spider gasket.  If the gasket has become worn and warped then the water will seep through the seam and end up in the waste.

The Fix: The solution is pretty simple, replace the gasket. Some gasket replacements are simple, remove the valve cover and old gasket, then lube in a new one. Other gaskets are glued into the diverter which requires a few extra steps.  If you want a step by step guide on the different ways to replace a spider gasket read this: How to Replace a Spider Gasket on a Multiport Valve

click here to find your replacement pool filter valve parts

The Diverter Spring

That tension we feel when spinning the selector handle is created by the diverter spring.  Besides making it hard to spin the handle, the spring serves the purpose of locking

Picture2the diverter against the spider gasket. If the spring in your valve is worn, it may be causing a seam between the diverter and gasket which shows itself in the form of a leak out the waste port.

The Fix: Replace spring, which to be honest, is not fun at all.  The spring is sandwiched on the diverter assembly which means it must be disassembled and assembled again. The hard part is getting the spring depressed enough to secure the handle pivot rod.  If you are feeling brave and want to attempt a spring replacement, please follow our guide: How To Replace a Pool Multiport Valve Spring

Valve Cover

The valve cover o-ring is found in the seam between the valve cover and main housing.  If water is found leaking from this seam then this gasket would be your culprit.  To access the gasket we would simply remove the 6 – 8 screws on the valve cover to remove it, peel out the o-ring, clean the groove, lube the new o-ring and re-attach screws.

The Fix: Read an inch above this line.

Valve to Filter Connection

Whether the valve is a top mount or a sidemount, it has to connect to the filter somehow.  At that joint connection there is a gasket holding on for dear life.  Because of the high flow at these connections, a blowout is somewhat common and easy to spot.

The Fix: Remove the valve from the filter and replace gaskets. Hopefully, the valve is piped in with unions so its removal is not a pain in the neck.  Once the valve is off, find the gasket and apply a freshly lubed replacement.

Thanks for skimming through our pool musings. If you have any further questions about pools, valves or otherwise, feel free to give us a call at 877-372-6038.

click here to find your replacement pool filter valve parts

119 thoughts on “Why Is My Multiport Valve Leaking?

  1. Hi, we have a strange water leak in our pool. It leaks only occasionaly, just up to the bottom of the skimmer level. Then for weeks it’s ok, then we lose water again! we’ve checked for wet areas around skimmer etc and all seems ok. i do know our Multiport valve has gone, the heavy spring doesnt work. When we move it we make sure it’s back in it’s proper place. There are no leaks within the pump room coming from the Multiport Valve so i guess it was ok. We’ve checked the main drain looking for any water coming out but cannot see any leaks in there either. Can there be underground leaks or leaks we cannot see if the Multiport Valve is causing this loss?

    1. Yes, there can be leaks from the leaks in the pool basin, but it would be odd for that type of leak to go away for a couples weeks then come back. The multiport valve could also be the issue, especially if your multiport valve spring is shot. A bad spring can cause water to flow through the backwash port. have you checked the area to where the backwash pipe drain to determine if the area appears wet when it shouldn’t be?

  2. My multiport valve is leaking under the handle (hayward), could it be the spring or the spider gasket? And could that leak be the reason why my pentair Intellichlor generator has a solid red flow light and salt water low light blinking red? I also hear bubbles coming from one of the return lines.Both returns seem to be full power (albeit the occasional bubbles). I already cleaned the Intellichlor cell with the acid, but there wasn’t any calcium in there anyway, this is it’s 2nd summer. After putting it back together, the flow light was green for about 10 seconds before going back to red.

    1. It would have to be a heavy flowing leak to compromise the flow switch in a cell. But your system sounds like it has two separate problems besides the cell: an air leak and leaking valve.

      The bubbles coming from your return are likely from an air leak. Here is a guide that can help you in find the source: How to Correct Low Water Pressure in Your Pool System.

      The leak from the top of the multiport valve could be a bad diverter stem o-ring or broken washer. You will have to open up the valve to take a look. I am not sure what which valve you have but this exploded part view of a valve may help. Key 7,8,and 9 are the washer, spring, and stem o-ring respectively. null

  3. Had a leak for while coming from the handle of the MPV. So took it apart, cleaned it, and reassembled. Smooth turning of the handle but leak probably a little worse. Plastic washer looked a little worn and was quite a gap from the plastic washer under the handle from touching the stem. So took back chance and bought a washer from a Hayward MPV as mine is no longer listed online or sold anywhere as it’s so old. Anyway, I reinstalled but it didn’t fix the leak from under the handle. So reinstalled and flipped the original plastic washer, still no joy. So I repeated procedure and added vaseline to plastic washer and metal washers either side of the spring. Still leaking. Can’t see any cracks, spring has lots of tension in it. Can’t see what the problem is. Please help?

    Also does it matter how tight I tighten the 6 screws? Will it make a difference?

    Just to confirm I have no leak from the sides of the MPV. The metal washers either side of the spring are not bent and look true. They are identical when paired together. What’s my next step?

    1. What is the model number of your valve? I need to get an idea of what you are working with.

      As long as the screws/nuts aren’t juggling they should be tight enough to prevent leaks.

      1. Thanks for the reply. Where can I find a model number of the valve? The only markings or name is on the handle itself.

  4. I have a Pentair 261050 high flow valve that was sticking awfully on turning. It never actually leaked, but I always thought it not good that it make loud creaking noises when turning it. I figured maybe something inside just needed a lil lube. So I disassembled it (8 screws) and the washers look a little bent but otherwise everything looks fine. The spring has a lot of tension. No damage seen to gasket or diverter. So I cleaned everything and wiped the spring and washers with a paper towel that had a little wd40 on it and put everything back to gether. The valve now turns smooth as butter but there is a tiny leak under the handle. A little bit of water collects under there, not a huge leak. So I took everything apart again, and took the oring off the diverter (which wasn’t easy) and lubed it, and put everything back together again but it still leaks a little under the handle. I ordered a new oring and will see if that helps. Someone suggested it might be my spring but I don’t understand how. It has a lot of tension. The handle does jiggle but the handle screw is threaded. Considering the handle is simply used to lift the diverter I don’t think this is the cause of my problem. I ordered a new handle too anyway. I guess I’ll order a spring next, and washers next. I hope I don’t need a new valve. Your opinion?

  5. I have a sta rite sand filter and it is leaking slowly out the waste port. It will stop when the filter is set on recirculate, but is leaking when on filter. Any suggestions??

  6. Hi. We have a Hayward Series Vari-Flo XL. We have been having problems with our filter not properly filtering and now we have an algae issue. We noticed when vacuuming the pool green was coming back into the pool. My husband took out all the sand, checked the later assembly intake valves and then replaced the spider gasket. When putting everything back together; we now have water coming up from under the handle. Help! My daughter is having her 8th birthday party in 3 days. Any help would be appreciated.

    1. The two problems are separate issues. If you have green water going into a filter, green water is going to come out. You need the shock your pool, and add algaecide to kill the algae. Read/watch this guide: How to Clean a Green Pool?

      And you are seeing a leak from the multiport valve handle because either a gasket or gasket is broken on the diverter stem. Or they were dislodged as you were servicing your filter.

  7. I have Pentair filter. When filtering, I have a leak coming through the hole in the stem of the air pressure relief knob. The local store says to replace the whole valve. Is there a way to fix the leak instead?

    1. Tim, did you find something to solve your problem? Mine is the exact same as yours. I was able to solve it a few years back by bet this – putting crazy glue around the top part of the hole where the pressure valve goes in but this year that isnt working. I really dont want to buy a new one!

  8. Matthew, I have a 12,500 Gal salt water pool with a Pentair 1.5 HP pump and a Pentair SD-80 sand filter with a 1.5″ multiport valve. The valve handle is on top of the sand filter and I have noticed while the pump is running in the filter position the MPV leaks around the handle, haven’t noticed this that much in the backwash or rinse positions but its probably as bad too. Also the handle seems to have a lot of play in it. The sand filter also drips from the drain plug in the bottom and the sight glass, not bad but if I am going to fix one thing I might as well fix em all . Otherwise the filter cleans the water and holds pressure fine, I think its the spider gasket and spring but don’t know how to go about replacing it, isn’t there a certain procedure to follow?

    1. The handle problem you are describing sounds like a bad diffuser spring and/or diffuser stem part. In the diagram below, in Box 1 we see all the parts contained on the handle-to-diffuser assembly. The Spring marked as Key 8, the Washer as key 7 or The o-rings as key 9 are likely bad are all things that can cause the leak or the handle to have too much play. We have guides on how to fix the problems in on DIY section.

      How To Replace a Pool Multiport Valve Spring

      1. Matthew I don’t see a diagram, I looked at the diagram for the Sand Dollar filter but it only lists a box 1B which is the full Multiport valve and does not break it down to the diffuser parts.

  9. Hi,
    I have a Waterco T600 filter and it nearly drains my pool when its on filter,and if i put it on waste it drains but at the same time you can see the dirty water returning to the pool.Could this be the spring on the multiport valve?

  10. My spider gasket and the diverter spring failed on my Hayward VariFlo XL valve, so I purchased a new valve to replace it with. After removing the 6 screws I pulled off the old valve and installed the new. I noticed that there was no gasket between the diverter and the multiport valve housing. After tightening down the bolts in a star pattern I had a lot of seepage coming from that seam. I cannot seem to stop it completely. I removed the valve, cleaned the mating surfaces thoroughly and applied a layer of plastic epoxy between the two surfaces. After curing the leaks are mostly gone, however I am still getting a slight leak from one area between two screws. Could the mating surface of the multiport housing be warped or should there be a gasket between the two surfaces? The new valve didn’t come with one, nor did the old valve have one installed.

  11. If there is a leak in the multi purpose valve, could this cause the creepy not to function? There is leaking around the valve handle, bubbles shoot into the pool (but no jet of water) and there is no suction on the creepy.

    1. The multiport valve is on the pressure side of the system, so it should not cause your Krauly to not work. Have you checked the cleaner’s hose for air leaks, or the cleaner’s disk and foot pad for excess wear?

  12. Spring is not slack at all. The cloudiness started about 2 weeks after the new filter was installed. I thought it was a chemical issue at first. Chemicals are perfect according to a local pool store. The first time I used the waste was this past weekend. Thats when I realized the water was going to waste and returning to the pool. Before that though i was noticing sand returning into the pool but I thought maybe because we had just changed it out that it was normal. Now more and more is coming in.

    1. Because you are getting sand in the pool, you may have a lateral or standpipe issue but that does not explain the water going the wrong way. Before you had the water diverting issue did you remove the valve cover or check the spider gasket?

    2. Was the MultiPortValve brand a CMP product? They had huge issues with the entire line of valves and have never been able to fix the quality issues. Buy OEM always……cheap product is well just cheap product…. i.e. CMP

  13. Help!! I have a brand new Hayward S210 Pro Series Sand Filter. When i try to send my vacuumed water to waste, the water goes to waste AND returns into my pool! I can’t get in touch with Hayward. Wait times to talk to them are 20 plus minutes. My water is extremely cloudy so I used floc in it and now can’t vacuum it out because some dirty water is returning to the pool. Sand filter is only 40 days old!! I’m hopeful its a warranty issue but I can’t get in touch with Hayward to find out. Spider gasket looks good and so does the spring.

  14. Mathew, I was wondering if you could help me. Our pool company recommended we change the filter gasket since the pool vacuum was unable to get good suction. (We checked the hose for any tears and had the pool company try their vacuum and had the same issue.) so we purchased a gasket and after changing it there is water gushing out of the filter by the top where the handle is. We cannot run the pool now because the amount of water is so much. We took a before picture to make sure we lined everything up the same way when we put it back. Any help would be greatly appreciated.

    1. Mia,

      Did you replace the main tank gasket of the filter or a gasket on the valve? If there is water escaping from the multiport valve handle, you likely have an issue with the o-rings or washers on the diverter stem. Can you provide the part/model number of the multiport valve?

  15. Thanks for reply. Yes I tried another gauge, same read exactly 10 psi. Will disassemble and check grids again for defects. Good suggestion checking waste port for leaks, will do that too.

  16. I don’t have any visible leaks, but my filter pressure is not rising – it’s been fixed at 10 psi all season. Not normal. Also, some material I vacuum comes back in returns. Filter grids are new, so could it be bad multi-port valve?

    1. First thing, have you tried changing the pressure gauge? It may be reading a constant 10 psi because it is broken.

      The dirt showing up in your pool may be torn grids (even if new) or a manifold issue. The only way to know for sure is to take it apart to find the defects.

      The normal sign for a defective multiport valve is water where it should be i.e. flowing from the waste port when set on regular filter mode or from the valve housing itself.

  17. My filter is leaking where the multi port valve attaches to filter ball.pours out checked the o ring looks fine put lube on it put it back still leaking?

  18. The other day we tried draining some water from the pool now it won’t stop leaking/draining from the waste end. I don’t know if it got stuck on drain or if something else is wrong with it. We tried moving it to filter and even close and it keeps draining even when we unplug the whole thing

  19. I have water leaking out the pipe that backwash water runs out of, when it is on filter it leaks bad out there we have to add water to our inground salt water pool twice a day

    1. If the valve handle is not too jiggly, it sounds like a bad spider gasket.

      Do you know the model number of your valve? I may be able to find you the correct replacement gasket.

    2. I have a brand new filter and pump, and having the same problem. Why is water running out of the waste port after the pump runs for a time and I’m trying to filter my pool to clear the water

  20. Water is leaking from under the valve, it looks like its coming from where the valve and tank meet. Is this the regular gasket, o-ring or spider gasket?

      1. Hi Matthew, I’m having the same problem (valve leaking from underneath). I have a Hayward multi-port valve, model sp-715-a 50 that connects to a DE-6020 filter. it’s an older unit, and it looks like the new model # is SP0715XR50.

        1. Hello Eric,

          The original poster has a top mount sand filter, which is going to have a different configuration than your sidemount DE filter. Can you give more detail as to where, underneath? Like is it coming from the main body of the valve, underneath the valve cover(where the Backwash, Rinse, and Filter sticker is, or from the unions that attach to the tank?

  21. I am getting small air bubbles blowing into the pool with the return water. Is this caused by a bad spider gasket?

  22. My valve is only leaking when on “filter”, and by leak I mean it is flowing almost as much as when it is on backwash. It is air tight when on recirculate. Any suggestions on what component might be the culprit?

      1. I just purchase a new valve and gasket and it is very hard to go from rinse or backwash to filter, it is leaking by, in filter mode

        1. Because the valve is new, the diverter spring is going to be hard to compress. It should unstiffen over time. As for the leak, we covered that in the article, try opening the valve to see if the spider gasket is out of place.

      2. I actually am having the same problem as Sarah. I recently had a broken lateral line, so we purchased a replacement lateral line assembly from you guys. It works, but like hers, the water is coming out of the waste/backwash port when it is on filter. I do notice the handle seems a little loose, but when you take out all the screws and take the head off then the handle is tight again. The gasket seems to be fine.


        1. On rare occasions, the spring can lose some of its stiffness. So, when your water pressure rises, the diverter will rise just enough to allow water out the wrong port. This is a problem that would only present itself when the valve is under pressure, and hard to test for.

          1. I went ahead and purchased the whole top multi port . We put that on and it still leaks just as bad as it did with the old one. Any other suggestions?

    1. I had the same problem, even after replacing the spider twice!
      The culprit is a broken or collapsed side wall grove that holds the spider in place on the backwash sector. the spider gasket then cannot be held by both sides in its groove/position and thus during filter mode, water shushes through this into your backwash.
      Solution is to buy a new multi valve.

      1. I found after replacing the valve 3 times that it was an issue with the water pressure in the pump causing the leak. I adjusted my inlet and outlet water and it works perfectly now.

        1. Jason how were you able to adjust you inlet and outlet water. I also changed my valve 2 times and still I have the same problem of leaking.

    1. Hello Henry,

      Under the handle, on the stem of the diverter there are gaskets at the base of the spring that are meant to prevent such a leak. If your valve is leaking from under the handle the gaskets and/or spring are likely worn, or they are out of alignment. These guides should give you some more insight on how to disassemble and the location of the parts: How To Replace a Pool Multiport Valve Spring and How To Replace a Pool Multiport Valve Handle

      1. Hope I can post here about my own pump leaking from the hole under where the handle goes into the pump on the top of my Hayward DE filter pump….hope this is something I can fix myself?

      2. I have a triton multiport valve that is leaking water from where the handle attaches. Just had the spring, washers, o ring etc. replaced. Any idea why it’s leaking?

        1. There may be a crack in the cover? A replacement cover can be purchased (depending on the valve model number), but a key cover and handle assembly should fix the problem altogether.

        2. Pool is only losing water when running but nothing is leaking out that’s visible above ground . I do not have a waist line as my system is closed . ( I think ) my hot tub is draining back into pool but I believe check valve is problem . My pool has been off for a week with no loss of water including skimmers . I cannot see any bubbling above ground . In ground gunite pool .

Leave a Reply

Your email address will not be published.

Recommended Resources

how to fix a pool filter lid

Poolside Chat Episode #20: Should I Fix My Cracked Filter Lid?

This is Poolside Chat where every week we answer your questions on how to fix and maintain your swimming pool. Poolside...
Read Now

Should I Fix My Cracked Filter Lid?

February 16, 2016
Should I Fix My Cracked Filter Lid? In this video, we look into whether or not you should fix your cracked...
Watch Now

When Would I Use The Waste Position On My Multiport Valve?

Do you have a diatomaceous earth(D.E.) or sand filter? If so, you may have a multiport valve that controls the filtering,...
Read Now

Looking for pool parts?

Shop Motors Shop Filters Shop Pumps Shop Salt Systems Shop Lights Shop Cleaners
Copyright © 2020 INYOpools All rights reserved