How To Replace a Pool Filter O-ring on a Cartridge Filter


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A Pool Cartridge Filter has an O-ring between the filter head and the filter body. If you see water leaking or spraying out at this junction, it's time to replace this O-ring. This guide shows you how to replace the O-ring on a typical pool cartridge filter. Note: We'll be using a D.E. filter for this guide.


Step by Step


Step 1

The first step is to shut off power to the pool pump at the circuit breaker. This will stop the flow of water through the pool filter.

Step 2

Next you will have to relieve the pressure that has built up in the pool filter. Note the pressure on the pressure gauge. It will typically read between 15 - 20 psi. To relieve pressure turn the air relief valve on top of the filter counter clockwise. Water will spray out initially as you see the pressure on the pressure gauge go to 0 psi.

Step 3

To access the pool filter cartridge O-ring you will have to take the pool filter head off the top of the filter. Turn the locking knob counter clockwise until you feel the pool filter head is loose. Note: The locking knob does not come off the top of the filter head.

Step 4

Lift the pool filter head off the top of the filter. It may be a little hard to lift initially as you break the O-ring seal between the two pool filter parts.

Step 5

The Pool Filter O-ring should be in a groove in the collar of the filter head. If it's stretched like this one, it may fall out of the groove - a good indication that it's time to be replaced. Roll the O-ring out of the groove and off the filter head collar.

Step 6

Clean out the groove with a damp cloth.

Step 7

Inspect the new O-ring for any factory defects like cracks or bulges. Roll the new O-ring into the groove of the filter head.

Step 8

Apply a thin layer of silicon based lubricant onto the Pool Filter O-ring. This will help preserve the O-ring. Do not use petroleum based lubricants, like petroleum jelly as these will deteriorate the O-ring.

Step 9

Replace the pool filter head on top of the pool filter. Position the top so that you can read the pressure gauge.

Step 10

When replacing the filter top, watch that the Pool Filter O-ring doesn't bulge out of its grove. This becomes more of a problem as the O-ring becomes older and stretches. It should not be a problem with a new O-ring.

Step 11

Hand tighten the locking knob clockwise

Step 12

Turn on power to the pool pump to repressurize the pool filter.

Step 13

The air relief valve should still be open. As the pressure builds, air will be released through the relief valve. When water starts to spray out of the valve, turn the valve clockwise to close it.

Step 14

Check the pressure gauge. It typically reads between 10 - 20 psi but this will vary according to the make of pool cartridge filter or its age.


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InyoPools Product Specialist  Posted: 8/17/2013 

luis - If you are replacing your old DE filter with an identical DE filter and you can keep your old multiport valve, you can unscrew the collars going to the new DE filter tank and reattach the ports when you have replaced the filter. If you are not replacing the same DE filter, you are probably going to have to cut the filter out at the multiport valve. The new filter will generally not line up with the old piping.

 Posted: 8/16/2013 

im trying to replace my d.e filter for a new one. its not a cartdrige filter is the hayward pro-grid vertical de filter. how do i remove the old one with out cutting the pipes?

InyoPools Product Specialist  Posted: 4/28/2013 

loose canister - Generally once the canister is placed into the filter tank, it is locked in place when the top of the tank is replaced. Make sure you have the right size cartridge and that it is placed all the way down when it is replaced. If you are having black pressure problems when you shut off your pump, check for clogs in your system after the pump. If cleaning your cartridge does not help you may have to purchase a new cartridge.

Anonymous  Posted: 4/26/2013 

What if the bottom of the canister does not stay tight and it blows off under pressure

 Posted: 6/3/2012 

Such a simple fix. Helps me save money. I thought I needed to buy a new pool filter