How To Replace the Hayward CL220 & CL110 Lid O-Ring


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In a chlorinator, the most common o-ring that causes leaks is the lid o-ring. Finding the correct o-ring and ultimately replacing it, is a common duty pool owners will find themselves doing. Using this guide, you will have your new lid o-ring changed in no time.

Things You'll Need

Small flat head screw driver

Socket set

Protective eyewear

Rubber gloves

Step by Step


Step 1

Before starting, I cannot stress that you should do this in a very well- ventilated area, outdoors if possible. Chlorine gas is very dangerous and should be taken seriously.

Step 2

First,turn of the pump and filter. Once the pump and filter have been turned off, remove the lid off of the chlorinator. If the lid is difficult to remove, the lid wrench will make it easier.

Step 3

Remove the protective cap that is covering the retaining screw. You can do this by inserting the tip of a flat head screw driver into the slot of the cap.

Step 4

Once the cap has been removed, the retaining screw is now visible.

Step 5

While wearing rubber gloves, hold the bottom half of the cover in place. Using either a number 19 or a 3/4 socket, begin loosening the screw.

Step 6

Once the retaining screw has been removed, the two main parts that make up the cover can be separated. Make certain to notate the position of the white plastic washers.

Step 7

The o-ring should be visible now. Using a flat head screwdriver, pop the o-ring off the bottom part of the cover disk. Once the o-ring is removed, clean the o-ring seat and cover threads using a brush or a rag and warm soap and water.

Step 8

Lubricate the new o-ring using a non-petroleum based lubricant, and begin installing it by pressing it into the groove. The lubricant will help prevent the o-ring from getting “pinched” when the cover is threaded back on. The application of lubricant will also help protect the o-ring from corrosion caused by the chlorine.

Step 9

Work the o-ring into the groove using your fingers as pictured.

Step 10

Before assembling the cover, make certain that the two plastic washers are in place and properly seated. Otherwise, the cap/cover will leak. This is the washer on the cover.

Step 11

When the two halves are put back together, both the top and bottom washer should be aligned and should fit into the groove on the cover.

Step 12

You can now install the retaining screw to hold the two halves together. Make certain not to over-tighten the screw otherwise it can break.

Step 13

Befor installing the screw cover cap, make certain that the groove is lined up with the notch on the cover. This is the groove on the cap.

Step 14

This is the groove on the cover.

Step 15

Once they are aligned, the cap can be easily pushed down into place.

Step 16

The cover assembly is now fully assembled and you can install it back onto the chlorinator.

Step 17

Once the lid has been installed onto the chlorinator, you can turn on the pump and filter to check for leaks. If there are leaks present, turn off the pump and filter and review the steps above.


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InyoPools Product Specialist  Posted: 8/5/2017 

Trasky - Try using a solution of TSP. You can buy TSP at any hardware store.

 Posted: 8/1/2017 

It seems that my cover gets more difficult to close over time - i'm seeing a buildup of - what I am assuming is the breakdown of the gasket and it is mucking up the threads. I tried soap and water but it just isn't getting it clean - do you recommend any other type of cleaner that may work? THe build up is on the threads of both the chlorinator and the cover.

InyoPools Product Specialist  Posted: 8/30/2016 

tomt - Try going through this guide again step by step. Make sure there are no cracks in the cap or the washers. And be careful not to overtighten the nuts when you put it back together.

 Posted: 8/29/2016 

The lid on my cl220 hayward chlorinator leaks. I have replaced the o ring but it still leaks. This is my third chlorinator for the same problem.are the chemicals warping the device. I have noticed that the top goes past the lid lock and the top can,t go any farther. I haven,t been able to get an answer any where.

InyoPools Product Specialist  Posted: 6/23/2015 

aj - Sounds like you have enough issues that it's time to get a new chlorinator. I would suggest switching to a "Rainbow 320 Inline Chlorinator". They are quite popular with fewer problems then you are having now.

 Posted: 6/23/2015 

you should be able to push down and rotate to unlock. That part has been broken for many years.

My problem is my chlorinator leaks at high flow rates (vsp)
Replacing o rings doesnt help. I can't find a properly sized o ring that fills the groove completely and compresses upon tightening. The other problem maybe the lid or female thread on the chlorinator not sealing, despite needing a strap wrench.
Im having trouble deciding on a new chlorinator or a custom wrench and oem o ring. The rainbow chlorinators are well reviewed


 Posted: 5/15/2015 

Does not mention if you are to push the lid lock on the side before removing cap, seems that if it "clicks" to let you know when lid is tight, then one would think it has to be released before lid can be unscrewed. Yes, no?

 Posted: 5/28/2013 

Thank you, now even I can fix.