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Maintenance tasks around the house could be annoying sometimes, but they are extremely necessary. The last thing you want to have is a mess caused by malfunctioning water filter cartridges because, when those parts are not working properly, you will notice it pretty quickly.

Not only do damaged filter cartridges lower the water quality, but they could also turn the water into an unsanitary element that we won’t be able to use for daily routines.

How To Change Water Filter Cartridges Under Sink?


No, you don’t want any of that, and neither do we. That’s why in this article, we’ll go over the steps needed to find the cartridges and replace them in due time.

Furthermore, we’ll go one step beyond by giving you the information necessary to perform thorough cleaning maintenance on the filter and its pieces. That way, you’ll keep every single part working at an optimum level to guarantee your home receives high-quality water.

How To Change Water Filter Cartridges Under Sink: Step By Step Guide

Step One: Preparations

As you’d do with any other maintenance task, you should prepare the equipment you will be removing. In this case, you’ll have to shut off the valve responsible for controlling the water flow into the system. Close the valve, make sure to tighten it up, and then continue with the next step.

After shutting off the water supply line, the next thing you want to do is get rid of the excess water stored in the filter. Proceed to open the faucet and let the water come out. Doing this process guarantees proper relief of the pressure inside the equipment, and it also reduces the leaking.

Step Two: Removing the Pieces

Use a housing wrench, or your bare hands, to loosen the filter housings. While doing this step, make sure to be very careful, hold the filter housing in a vertical position to prevent the water from making a mess. If necessary, put some cleaning cloths below.

Now, you should be able to take out the housings and the cartridges.
While you’re at it, you could check the O-rings located in the filter housings. Professionals recommend changing these parts annually. Even though it is not strictly necessary, replacing them every year could be a good decision to prevent any malfunction in the future.

Get the O-rings out as well as their groove, and wipe them clean. After installing the replacements, make sure they are in the right position.

Step Three: Check the Removed Filter Cartridges

After removing the cartridges, take a moment to check their state. If you notice an impressive amount of sediment build-up, perhaps you’ll need to replace the cartridges more often than you’d think. Or, if it is within your possibilities, add a pre-filter cartridge to the system.

Step Four: Cleaning the Housings

The next step is to clean the filter housings. You can use soapy water, which could be warm for better results. As for the cleaning tool, you could use a soft-bristled brush. Proceed to do a thorough cleaning inside the housing caps, and finish up by rinsing the pieces with clean water.

Step Five: Creating a Sanitizing Solution

Pour one gallon of clean water inside of a bucket. Then, add unscented household bleach to the water. While some people recommend adding 1/3 teaspoon of that substance, other sources recommend three tablespoons.
Lastly, you’ll be adding one cup of the sanitizing solution to each one of the filter housing sumps.

Step Six: Connecting the Pieces Back Together

Proceed to connect the housing sumps once again, now with the caps sanitizing solution. For this step, you don’t have to attach the cartridges.

Step Seven: Opening the Shut-Off Valve

Continue with the process by opening the shut-off valve, and let the water fill the housings. Once the water starts coming out of the faucet, you can close it.
Then, let the water flow together with the bleach, making sure both elements get in contact with the housings, the lines, and the faucets for an estimated time of thirty minutes.
When the thirty minutes have passed, take out the filter housing sump following the same steps you did before: shut-off the valve, get the housings out, and get rid of any sanitizing residue in there.

Step Eight: Placing the Cartridges back

To finish up, you’ll have to place the cartridges back into their place. Deciding the order may depend on personal preferences. Nonetheless, it is better to put the carbon block cartridge in the first housing, and then follow up by adding the KDF/Gac cartridge in the second housing.

Step Nine: Run Some Tests!

Open the valve and let the water run through the cartridges. Give it a couple of minutes to flush and activate the filters properly. Then, close the faucet and check if there are no leaks.
If you follow those steps carefully, not only will you be able to replace your filter cartridges, but you’ll also perform a thorough maintenance task to guarantee everything works fine.

While handling bleach and other chemicals, make sure to use some gloves and proper protection to prevent any unpleasant reaction on your skin.
Also, if you’re having trouble with the steps, you could have someone with more experience to give you a hand for reducing the risks of unwanted incidents.

Final Words

Replacing the filter cartridges is necessary when you start noticing a decrease in the quality of the water that goes into your household. Of course, they’re not always the cause of the problem, but they are a good place to start looking.

Granted, the title of the article suggests we would only replace the cartridges, but doing the complete maintenance process ensures nothing can mess up your water filter.
Our article covered the essential steps required to get the cartridges out, clean the housings, and place everything back together in its place.

Even though following the steps described in the article may be easy, inexperienced homeowners may need some time and plenty of patience to get the job done. Don’t lose hope, and follow through until you get everything clean and the cartridges replaced.