How to Replace a Spider Gasket in Multiport Valve

The spider gasket, also known as the spoke gasket or seal is located in a pool filter’s multiport valve. It’s a common cause for water leaks from the filter or poor filtering performance.

In this article we’ll show you how to inspect it, clean it or replace it. It’s an easy job any DIYer can handle. Let’s get stuck into it.

What Does the Spider Gasket (Seal) Do?

Firstly before we get into replacing it, let’s have a quick recap on what the spider gasket (spoke seal) does.

The multiport valve works by directing the water flow through a series of chambers depending on the function selected. The spider gasket is located inside the multiport valve of sand filters and Diatomaceous Earth (DE) filters and provides a seal between each of these chambers, ensuring that the water is directed the right way depending on the filter function selected.

These functions could be:

  • Filtering
  • Backwashing (or Waste)
  • Rinsing
  • Recirculating
  • Winterize
  • Close

Spider Gasket

Spider Gasket, Astral, 1-1/2" Multiport Valve

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Why Replace the Spider Gasket (Seal)?

So now we know that the spider or spoke seal is responsible for directing the water the right way through the valve. If this seal is worn or isn’t seated correctly, it means the pool’s filter will not function correctly.

A worn or defective spider gasket could mean:

  • Water leaking through the backwash or waste outlet
  • Poor filtering performance
  • Low filter pressure
  • Some filter functions not working (like backwash, filter, recirculate etc).

If you have any of these issues with your filter, before you replace the spider gasket, try the following:

  • Backwash and clean the filter
  • Clean out skimmer and pump baskets
  • Check for blockages in the pump
  • Make sure all unions and pipe joines are tight
  • Your pump is primed properly

If you’ve done this and still have issues, it’s time to check the spider gasket for issues.

How To Replace or Repair A Damaged or Worn Out Spider Gasket

The only way to fix a damaged or worn-out spider gasket is to replace it with a new one. This method is similar for many multiport valves, including:

  • Hayward multiport valve
  • Pentair multiport valve
  • Waterco multiport valve
  • Onga multiport valve
  • Poolrite Enduro multiport valve
  • Starite multiport valve
  • Astral multiport valve
  • Hurlcon multiport valve

If you prefer video instructions, check out this video.

Here are the written instructions of how to replace a spider gasket:

1. Turn off the pool pump

Turn the pump off at the breaker, release the pressure from the pool filter by opening the pressure release valve.

2. Remove the multiport valve head

Do this by undoing the screws on the top of the valve and then lifting the head and separating it from the body.

3. Remove & Inspect the spider gasket

Before you remove the spider gasket, take a note of how it is seated. It should be sitting flush. If it’s twisted or out of position, that will cause a leak and it needs to be replaced.

You can now remove the gasket. Inspect it for cracks and check its shape. If it is misshapen or cracked or broken, you’ll need to replace it with a new one.

4. Clean the gasket surfaces

Another common cause for multiport filter valve leaks is the surface that the spider (spoke) gasket sits on is dirty and caked with gunk. Use a plastic scraper to clean this off the valve body. Remember to do the top and bottom parts of the multiport valve.

5. Fit the new spider seal

Before installing the new spoke gasket, compare it to the new one and make sure it is the right size and shape.

Drop in the new seal taking note to make sure that it aligns with the chamber of the valve. Make sure it is sitting flush otherwise it will not seal correctly.

Tip: if you’ve recently replaced the spider gasket and it keeps moving out of place, you can glue it down to the ports to keep it locked in place but it’s best not to do this unless you need to as it will make removing it in the future difficult.

6. Reassemble and test

After carefully positioning the new gasket, put the head of the multiport valve back being careful not to move the seal. Tighten up the screws then turn the pump back on.

You should bleed the air out of the filter when you do this too. Here’s how:
How to Bleed Air From a Pool Filter (answered!)

How to Maintain a Spider Gasket

Proper maintenance of your pool filter will extend the life of the filter and also the spider gasket and multiport valve. Here’s how to maintain your multiport valve.

Keep Pool Chemicals Balanced

There are many parts in your pool’s system that need proper chemical balance. Maintaining a pH level of between 7.4 and 7.6 will help prolong your pool’s system. If it is too basic or acidic, this will corrode your pool’s components and spider gasket.

In addition to this, keeping the chlorine level between 1 and 5 ppm will also extend the life of your pool’s spider gasket. Strong concentrations of chlorine will degrade all of your pool’s system.

Regularly Remove Debris from Pool

Keeping the debris out of your pool will not only mean a better swimming experience for you, it means you’ll need less chlorine, and it will keep the dirt from building up in unwanted places, like your multiport valve.

removing debris from pool
removing debris from pool

Keep Skimmer and Pump Baskets Clean

Clogged skimmer and pump baskets are the cause of many filtering issues. Not only does this strain your pool’s pump, it means extra debris inside your filter which can stick to the multiport valve and clog up the gaskets.

Clean Multiport Valve Once a Year

And the final tip to extend the life of your spider gasket is to regularly clean out your multiport valve. As mentioned earlier, dirt and gunk do build up inside your valve. And when this happens, it may not seal properly or the functions may not work at 100%.

Dismantle your valve and clean out the gunk regularly to keep it working at 100%.

multiport valve sand filter
multiport valve sand filter

Conclusion

The spider gasket (or spoke gasket) is a common culprit for your pool’s filter not working correctly. From leaks to poor filtering performance to low filter pressure, all these common problems can be caused by a damaged or broken spider gasket.

I recommend that you check this gasket if you are having issues with your pool filter and at the minimum, clean out the valve housing once a year to ensure your pool filter functions at 100%.

Happy swimming!

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