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How to Install Under the Sink Water Filter?

How to Install Under the Sink Water Filter With Faucet?

Under-sink water filters are your best bet if you’re looking for a cost-effective solution compared to whole-house filters.

Under the sink water filters provide a discreet filtration system, saving you lots of counter space and providing easy access.

But what is an under-sink water filtration system and how to install it? We’ll uncover these topics and many others in the article today.

Let’s begin!

What Are Under-Sink Water Filters?

Under-sink water filtration systems are installed under the kitchen sink to filter water for improved taste and odor and reduce contaminants from your tap water.

Unlike whole-house filters, under-sink water filters are convenient and readily available, keeping your water clean and countertops clutter-free.

Under the sink water filters are an excellent option if you want filtered water for cooking or drinking purposes only.

What You’ll Need for Under-the-Sink Water Filter Installation?

The tools and equipment to install under the sink water filter system are as follows:


  1. Electric drill
  2. Water filters and cartridges
  3. Sharp scissors or cutters
  4. Screwdriver
  5. Pliers
  6. Adjustable wrench


  1. Teflon tape
  2. Bucket
  3. Pencil or markers
  4. Sandpaper (optional)

Step-by-Step Guide On Installing An Under-Sink Water Filter System

Installing an under-sink water filter system is fairly easy if you’re equipped with the right materials. Also, if your under-sink water filter comes with a faucet, make sure to drill the hole for the faucet beforehand.

Here’s a step-by-step guide on installing an under-sink water filtration system.

Turn Off Your Cold Water Supply

First of all, place a bucket under the connection point to prevent leakage or flooding and catch any drips during the process.

Before starting, make sure to turn off your cold water supply using the wrench. You will find the cold water valve on the right side of the cabinet.

Disconnect the Tubing

Using the wrench, disconnect the tubing by simply loosening with the wrench. Now, disconnect the cold water supply that connects to your faucet.

Install a T-Adapter

T-adapter is responsible for diverting water to your new under-sink water filter system. Using the Teflon tape, wrap the threads on the adapter to make a watertight seal.

Place the T-adapter to the cold water shut-off valve using the wrench and tighten it carefully.

Connect the Tubing to the T-Adapter

If your filter system has pre-cut hoses, wrap the ends of the hoses with Teflon tape.
However, if you need to cut them, use sharp scissors and cut them cleanly.

Attach the inlet hoses to your cold water supply by connecting one end to the T-adopter. Using a wrench, tighten it carefully.

Connect the T-adopter’s other end to the filter housing’s filtered outlet and tighten the connection with a wrench.

Install the Faucet

Skip this step if your system doesn’t come with a faucet!

If it does, drill a hole using a drill machine to let your faucet fit securely. Please refer to the user manual of your under-sink filter for proper placement.

After installation, connect the faucet tap to the filter tubing with the supplies provided by your manufacturer.

Mount the Filtration System

This is the step where you secure your water filter underneath your sink.

Look for a suitable spot with enough space to accommodate the complete filter system. Also, leave room for regular maintenance and comfortable filter changes.

Avoid mounting the filtration system in locations near the cabinet floor or sidewall to prevent wobbling or vibrating.

Connect it to Your Plumbing

After you’ve successfully mounted your under-sink water filter, it’s time to connect it to your plumbing.

Identify the inflow and outflow ports (the inflow port carries untreated water for filtration and the outflow port carries filtered water to the new faucet).

Connect one end of the faucet tubing to the outflow port and tighten it securely with a wrench. Connect the cold water supply to the inflow port, and tighten it securely.

Before turning on the water supply, check out the connections for loose fittings or gaps.

Turn the Water Back On

Turn the water back on clockwise slowly and gradually and check for leaks.

If your water filter has a shut-off valve, make sure it’s open so the water flows through the filter.
Note: Losing a small amount of water during the initial setup is completely normal. However, any persistent leaks require immediate attention. If this happens, turn off the water supply immediately and tighten all the connections.

Contact with an expert if the problem persists.

Flush the Filters

Flushing the filters is the last step of installing an under-sink water filter that ensures pure drinking water.

Flush the filters while keeping the water supply on and checking the connections for potential leaks. Consult your user manual’s instructions on how to flush the filters properly.

Usually, the best way to flush the filters involves running water through the filter for a definite amount of time so any debris, contaminants, or carbon leave the system.

Once the flushing time is complete, turn off the water supply and discard the flushed water in a bucket.

Do You Need an Expert or Can DIY it?

Under-sink water filter systems are easy to install if you have extensive plumbing experience or if you’re comfortable DYing it.

However, if you have limited plumbing experience and knowledge about plumbing tools and materials, it’s best to hire professional installation services to install an under-sink water filter system at your home.

Watermart provides innovative solutions that treat the water you drink and cook with through under-sink cottage systems.

However, if you have an existing under-sink water filter system, our team of professionals provides exceptional installation and maintenance services to deliver pure, safe drinking water every time.

Benefits of Installing Under the Sink Water Filter System

Investing in an under-sink water filter system is the best decision of your life because it provides immense benefits for you and your loved ones.

  1. It gets rid of the unpleasant Chlorine taste and pungent odor from your tap water and makes it pleasant to drink and cook with.
  2. Under-sink water filters remove harmful contaminants from your tap water, including lead, mercury, and chlorine by-products to lower potential health risks.
  3. Many under-sink water filter systems target harmful microorganisms, such as E. Coli and cysts from your tap water to provide superior protection against harmful bacteria and other toxins.
  4. Under-the-sink water systems are versatile and can fit easily under any sink without compromising performance.

After the Installation of the Under-the-sink System

So, you’ve finally installed your under-the-sink water filtration system? It’s time to remember some important things to keep your system up and running effectively.

  1. It’s crucial to flush your water filter every 2 weeks to remove carbon particles and other contaminants.
  2. Replace your filter cartridges every 6 months to maintain superior performance and enjoy drinking pure and safe water.
  3. If you notice any leaks during the use, turn off the water supply immediately and consult an expert.

Under-sink water filters, however undemanding, can work wonders if maintained properly for a long time.


Under-the-sink water filters are ideal for you if you want filtered water for daily drinking and cooking in your kitchen for easy access. They are also a cost-effective solution as compared to whole-house filter systems.

The best part? You can install it yourself by following the simple steps shared in this article above.

However, if you’re not comfortable with DIY solutions for your under-sink water filter system, Watermart provides easy installation and maintenance services for all water filtration systems to deliver pure and safe drinking water.

Schedule a call with us today and book a service.


How Much Does It Cost To Install A Water Filter Under The Sink?

The cost of installation depends on many factors, including your location, cost of labor, and your water filter system.

However, the average cost of installing an under-sink water filtration system ranges from $200 to $350 in general.

Is An Under-Sink Water Filter Worth It?

If you need filtered water for cooking or drinking purposes in the kitchen only, an under-sink water filter is all you need for a healthier lifestyle.




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