how to replace an under sink water filter cartridge

It’s time to update your filter cartridge. We have all the measures and guidance you need on how to replace an under-sink water filter cartridge in today’s article. Enjoy more reliable water pressure, better-tasting and healthier water by upgrading now.

Step-by-Step Guide to Replacing an Under-Sink Water Filter Cartridge

Here are some easy-to-follow steps to changing your new filter and cartridge (even if you don’t have much experience). This is the equipment you’ll need:

  • Filter housing wrench
  • Replacement filters
  • Paper towels (for any water spillage)
  • O-rings

Step 1: Assemble Your Tools

The first task of replacing your water filter cartridge is to have all of the tools you need close by. So you don’t have to bump your head countless times, removing yourself from the cabinet to reach a tool. Ideally, have someone working with you to help pass you the tools you need.

Step 2: Switch off the Water Supply

It’s important that you switch off the water supply before beginning any work. Make this step your priority. Fortunately, most water filter systems feature a small valve located on the incoming water line before the water reaches the water filter system. Alternatively, other filter systems require that you switch off the water supply at the faucet valve directly under the sink.

Step 3: Loosen Filter Housings

Next, loosen any filter cartridge housings by hand or with a wrench. All the while, remain careful that the filter housing remains upright since it’ll be full of water. Then, remove any housings and filter cartridges that you plan on changing.

Step 4: Replace the O-Rings

It might be time to change the O-rings, which some manufacturers recommend doing annually. Remove the O-rings and replace them with new ones, ensuring that a positive seal isn’t possible if it’s properly positioned in place to prevent any water leaks. Furthermore, most filters feature two O-rings—one on either side of the cartridge. When removing each O-ring, make sure that the bottom O-ring isn’t stuck inside the filter housing.

Step 5: Inspect Old Filters

Spend some time inspecting that the old filter cartridges aren’t filled with build-up before you discard them. Next, clean the filter housings with soapy water and, if necessary, a soft brush. Ensure that you clean the filter housing caps and rinse them with cold water.

Step 6: Connect the Housing Pumps

Connect the housing pumps back together with the caps and open the shut-off valve to allow the housings to fill with excess water.

Step 7: Check for Signs of Mould

The last thing you want under your sink is to allow mould and bacteria to grow. Check for any signs of growth and, if necessary, use a sanitising product to prevent any build-up.

Step 8: Test the Faucet

Now it’s time to test that the faucet works. Allow up to 30 minutes for the water to come in contact with the housings, lines and faucet. After this time, you can shut off the valve and remove the housings.

Signs It Is Time to Replace Your Under Sink Filter Cartridge

There are several tell-tale signs to look out for when replacing under-sink water cartridges. Here are some of the most common ones to bear in mind.

A Drop in Water Flow

The first sign that you need to replace your cartridge is a drop in water flow. This typically slows down when contaminants and debris are trapped in the filter system, making it harder for clean water to pass through.

A Different Taste in the Water

Another popular sign to look out for is your drinking water tasting slightly off. Although tap water won’t always taste like bottled water or filtered water, it’s not always to everyone’s taste. Plus, it can often be an indication to replace your under-sink cartridge.

A Strange Smell

Finally, have you noticed a different smell in your tap water—specifically, an undesirable smell? This is typically a sign that your filter cartridges need replacing because there’s a build-up of contaminants.

How Often to Replace Your Under Sink Water Filter System

Generally speaking, you should replace your sink water filter every three to six months, though we recommend resorting to the three signs listed above because you might need to change them more/less frequently.

What Are the Benefits of Under Sink Water Filters?

There are several reasons to invest in an under-sink filtration system, and here are some of our favourites:

Enjoy Fresher, Tastier Water

It’s important to drink water often, but when your tap water is packed with chlorine and has an unpleasant taste, you won’t push to drink it as frequently. Fortunately, a new cartridge can free your tap water of a slimy texture and a foul odour.

Removes Harmful Pollutants

water from a faucet

Have you ever considered how many pollutants and bacteria are in your tap water? A filtration system can remove any harmful pollutants, improving the overall taste of water and your well-being. Additionally, a more advanced under-sink water filter system will remove heavy metals, cysts, herbicides, pesticides and more contaminates to reduce water hardness.

Reduce Plumbing Costs

Get right to the core of your maintenance costs by purchasing a new filter and cartridge. Cause not having an under-sink filter system can result in clogged pipes, while hard water reduces the lifespan of your appliances. Over time, these factors can cost you a lot of money in plumbing costs or in renewing appliances.

Enjoy Soft Water

Finally, enjoy the taste of soft water, so you won’t have to endure a chemical, bitter aftertaste.

Features of Under Sink Water Filters

Here are some of the main features of water filters.

Easy Installation

Water filters require minimal installation, and thus, you don’t need to be experienced to install one.


Best of all, a replacement water filter cartridge is cost-effective and budget-friendly, including both the upfront purchase price and any running costs.

Minimal Maintenance

Once installed, water filters require very little time and effort on your behalf. So you don’t need to regularly maintain them until it’s time to replace your cartridges.

Available in a Range of Models

Under-sink water systems are available in a diverse selection. So you have a huge range to choose from when it comes to removing fluoride, heavy metal and bacteria from your tap water. Moreover, there’s small, making them extremely compact—even if you don’t have much spare space under your sink.

stainless steel faucet

Installing a New Cartridge

Overall, keep your equipment near you and always switch off the water supply when learning how to replace an under-sink water filter cartridge. Check for any leaks and double-check that the O-rings are attached firmly and tight during the process.

Additional Resources

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