How To Replace a Pool Cartridge Filter


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Do you have an old filter that has seen the prime of it’s life? Perhaps you have a filter you want to replace or the housing is cracked and leaking. Have no fear, this is a relatively easy and inexpensive project. This guide shows you how to replace a Hayward Cartridge filter; however, this procedure is applicable to most other filters.

Step by Step


Step 1

TOOLS YOU WILL NEED: 1) Hack saw 2) Plumbing tape 3) Indoor-Outdoor silicon 4) Adjustable pliers with 2 gap minimum 5) Square corner ruler or level 6) Magic marker 7) Medium sandpaper 8) PCV Cement 9) PVC Cleaner

Step 2

Materials you will need: 1) Two PVC pipe couplings: One side threaded, the other side has no thread as PVC pipe will fit into the end. Measure INPUT and OUTPUT ports of the filter housing before purchasing. Typically it is either 1 1/2" or 2”. Once you establish the proper size, all other PVC material will be the same size.

Step 3

Materials (cont'd) 2) Four 90º angle PVC couplings (photo shows 2 styles to choose from) 3) PVC pipe - you will have to approximate or measure anticipated length. An 8' length is a good start. Buy extra, you can always return it. Make sure the pipe is labeled "schedule 40" to handle the water pressure.

Step 4

In this case, we have already cut out the old filter. If you have not cut out your filter, turn off electricity going to the pump motor via your fuse box, not just the timer. You don’t want the pump to turn on when you are doing this.

Step 5

Take the filter cartridge out of the housing so it doesn’t get damaged while you work, and put the top back on.

Step 6

This diagram shows you the flow of your water. NOTE: There was once a large sand filter here. Don’t let the height of the existing pipes throw you, we will trim these down.

Step 7

Put silicone into threads of filter housing and spin around with your finger.

Step 8

Wrap plumbers tape, counterclockwise, 7 – 10 times on threaded side of coupling. Install threaded couplings on both openings of housing. Use pliers to tighten. DO NOT OVER-TIGHTEN.

Step 9

Now position the housing where you want it. In this photo, the output port (the lower of the two) lines up directly with the existing outlet pipe to the pool. It is important that this is aligned correctly and that the INPUT and OUTPUT PORTS are positioned properly. Remember, the output goes to the pool pipe. If you are unsure, usually there is a diagram on the front of the filter. Make sure there is plenty of space on both sides. You want a minimum of 6” of pipe extending from each outlet.

Step 10

Cut a section of pipe that fits into the filter output port and extend it to the pipe that leads to your pool and cut to size. Test the length and then cement into the coupling.

Step 11

Now line up the filter output pipe with with the pipe to the pool, make a mark beneath the pipe with the marker and cut it so it butts up against the pipe. The pipe will slant down a little, lift it up to get a nice fitting. Use a corner ruler or level to ensure the pipe is straight. Cut with hacksaw blade under the pipe.

Step 12

Clean both sides of the 90º coupling. Rub the edges of the pipes a little bit with a file or sandpaper. Test the fitting before gluing to see if everything lines up correctly.

Step 13

Then brush pipe and coupling with PVC cleaner. After cleaner has dried, cement pipes and coupling together. This completes the output connection from the filter to the pool return pipe.

Step 14

Next we’ll connect the pipe leading from the pump to the intake port of the filter housing. Cut a 6” - 8” section of pipe and cement it into the threaded coupling you put in earlier. Put (do not cement) the 90º coupling at the end.

Step 15

Cut another piece of pipe that when sitting vertical in the coupling, extends above the motor at least 12” – 15” (you will trim this down later) and set into coupling. This will be your INTAKE PIPE. Make sure it is straight up and down (if not, you will have problems lining up the next coupling). Now you can cement the assembly.

Step 16

Go to the pump motor and cut the existing pipe extending from pump 4” – 6” above the fitting. Set the 90º coupling into this pipe. DO NOT CEMENT.

Step 17

Cut a piece of pipe that fits into the coupling and extends to the INTAKE PIPE to the filter and cut to size.

Step 18

With a corner ruler or level, make sure the top pipe is completely straight and level. Make a mark on the Intake Pipe and cut to size.

Step 19

Now put the coupling in (DO NOT CEMENT) and make sure everything lines up straight and correctly. Once you are confident that everything lines up, cement the whole Shebang together.

Step 20

Give the cement a couple of hours to set. Open the filter housing and check to be sure no debris or parts from your work have fallen inside. Put the filter cartridge back in.

Step 21

Turn on pump, and check for leaks. • Congratulations! You have just finished a job that can cost upwards of $100+ for a professional to install not to mention the markup on the parts

Step 22

Securing filter - It is up to you if you want to put the filter in a stationary position. If you do, wait until the entire filter with pipes is done. However, keep in mind that bolts can rust out and it will be difficult to take the filter off if you have to in the future. Typically, because of the weight of the full filter it is pretty secure.


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 Posted: 11/15/2012 

a client indicates that when they use spa the filter had a back flush from filter area what could the problem be?