Replacing of a Pool Filter O-ring on a Cartridge Filter

This guide discusses the procedure for replacing the O-ring on a typical pool cartridge filter. Note: We'll be using a D.E. filter for this guide.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. 

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.

2. 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.

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.

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.

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.

6. Clean out the groove with a damp cloth.

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.

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.

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

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.

11. Hand tighten the locking knob clockwise.

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

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.

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.

If you have any other questions about pool and spa products please do let us know - we are here to help!

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