How to Install a Water Filter With A Separate Faucet?

Whether it’s a private well or a public water source in your home, you’ll most likely need a filtration system to purify the water. The impurity level and use will determine the best filter system to install, with most cases requiring more than one filter.

Filter systems like whole-house filters clean the water entering the house and, as such, provide clean water in every outlet. However, the water needs to be cleaner for drinking and may require further cleaning. When it comes to drinking water, a more specific approach is essential, with filters attached to a single or double faucet to provide clean drinkable water.

Under-sink filters are the most common drinking water filters used in homes; however, several others can produce the level of purity you need for your safety. When it comes to installing these filters in your kitchen sink, it is always best to use a separate faucet from the standard water faucet in the sink.

If you want to install a water filter but are seeking to connect the filter to a separate faucet, this guide will show you how to achieve this setup. You’ll find all the steps to install a water filter on a different tap. But before then, let’s see why using another outlet for your filtered water is essential.

Why Do You Need a Separate Faucet For Your Water Filter?

You may wonder if using a different outlet for purified water is vital since you can easily connect the filter to the sink faucet. The regular water nozzle in the sink delivers water for all kitchen activities, including those without any need for clean drinkable water.

Connecting the filter to this outlet will mean all the water from there will be clean and drinkable, which sounds good. However, the filter would have to do more work to provide the water required. More work means extra pressure on the filter and reduced durability. Since the system is cleaning more water, the filters will get clogged quickly and require frequent maintenance and replacement.

To prevent sudden breakdowns due to stress on the filter, connecting the filter to a separate faucet is always the best option. This way, you use the nozzle only when you require drinking water, reducing the work done by the filter and increasing its lifespan.

Which Faucets Come With Water Faucets?

While you can install many filtration systems to clean the water in your home, two main filter types come with faucets, making it easier to have a different water outlet for the filtered water.

Under-sink and countertop filters come with faucets, so you don’t have to attach the filter to the existing water nozzle. Under-sink filters are connected to the cold water line, where they usually pass through several filters before coming out through its dedicated outlet. For countertop filters, water from the faucet is fed into the unit where filtration is done, and the water leaves through the nozzle connected to it.



Tools for this project include drilling, marking, and cutting materials to create the faucet hole and cut the pipes, among others.

Here is a list of all the tools you need:

  • Pipe cutter
  • Basic wrench
  • Adjustable wrench
  • Screwdriver
  • Drill
  • ⅛” and ⅜” drill bits
  • Knockout punch
  • Ratcheting box end wrench
  • Plumbers tape
  • Pliers
  • Rag
  • Bucket
  • T-valve
  • Washers
  • Flexible tubing

Step-by-Step Process to Install Water Filter With a Separate Faucet

Step-by-Step Process to Install Water Filter With a Separate Faucet

Here is a simple guide to installing a water filter with a distinct outlet without any plumbing and experience in under two hours. The process is simplified, so any DIYer can understand and follow its steps to fix a suitable water filter and its water spout. Here we’ll show how to connect the separate faucet to a sink.

1. Shut Off The Water Valve

Shut off the cold water valve, usually under the sink and along the cold water line. The aim is to prevent water from fusing out and filling up the area when you start working on fixing the water filter. You shouldn’t be inconvenienced with the installation process taking under two hours.

After shutting off the water from the cold water line, you want to open the faucet to drain the water remaining in the pipes while also relieving pressure. Place the bucket under the pipe area to catch any water remaining in the lines and prevent causing a mess when you cut the pipe.

2. Drill Countertop Hole

To fix that separate faucet, you need a hole in the countertop. Some counters already have predrilled holes, so you may not need to drill another hole here. However, when a pre drilled faucet hole is not available or in the proper position, cutting out that hole on the sink or countertop is the adjoining line of action.

Before you start, you want to determine the countertop material, which will choose the materials to use. Most kitchen sink countertops are made from stainless steel, so the steps here follow cutting a stainless steel kitchen sink.

  • Place the faucet escutcheon plate on the desired sink spot and mark the center.
  • Use a ⅜” drill bit to drill a pilot hole through the stainless steel sink, ensuring you increase the drill speed slowly while also increasing the pressure into the sink.
  • Slide a slug cutter through the pilot hole and secure it under the sink
  • Use a ratcheting box end wrench to tighten the turn and cut the sink
  • Use a ratcheting box end wrench to tighten the turn and cut the sink

3. Install T Valve

The T-valve allows you to channel the water in the cold water line to another direction while still serving the central sink sprout. Depending on the fittings, you may have to cut the cold water pipe to attach this valve. But before going ahead to cut, you want first to measure the correct filter position on the wall.

Under-sink filters are usually fitted through hangers that hold them to the wall. You want to choose a position where it’ll be easy to access and remove the filter cartridges for cleaning.

Mark that position on the wall and trace its closest point on the cold water pipe. With the help of the pipe cutter, you can cut the cold water slime and install the T-valve. Thread the plumbers’ tape before installing one end to the cold water inlet and the opposite end to the original faucet pipe.

4. Attach The Filter

Hang the filter on the wall using the marked spots as a reference, ensuring it is firm. With the filter firmly on the wall, attach a flexible tubing from the remaining T-valve end to the water filter through the IN valve. Connect the adjustable valve from the separate faucet to the OUT filter valve.

5. Turn on Water Supply and Test

Slowly turn on the cold water supply line previously turned off so water can replace the gas in the filter. Slowly opening any valve at this point aims to pressure a sudden heavy water pressure from damaging the filter. Slowly turn on the dedicated faucet and allow water flow while observing for leaks. The flowing water also helps clean the filter and prepare the water for drinking.


The importance of using dedicated faucets for your filtered water cannot be overemphasized; however, installation may raise a few questions. This is why we’ve dedicated this section to answering all the common questions about fitting water filters with dedicated faucets.

Which water line should you connect the water filter to?

Connect the water filter to the cold water line. Not only does hot water damage the filter, but it is also unpleasant to drink. In most situations, the cold water line is on the right, and the hot water by the left. You can also shut off each valve and check which nozzle still brings out water.

Can you install a water filter faucet on a ceramic sink?

Ceramic sinks usually found in the bathroom are almost impossible to drill without breaking, so it is not advisable to try cutting the sink for the faucet. Stainless steel sinks in kitchens are best suited for mounting water filter faucets.

Is a separate water filter faucet a must-have?

No, but having this option is excellent as it lets you keep your drinking water clean and reduces the pressure on the filter. Most reverse osmosis under-sink systems come with dedicated faucets, but you can also purchase a water filter faucet where necessary.

Where is the best position to drill a faucet hole?

The best position for your faucet depends on your preference and the length of the flexible pipe. Where the tube is short, the places you can choose are limited to ensure the line reaches the filter. You can drill close to the original faucet or at the opposite sink end.


Water filters with dedicated faucets are becoming quite popular due to their clear advantages as they reduce the work done by the filters, thereby increasing their lifespan. Most water filter faucets are lead-free, ensuring the pipes are not contaminated.

Installing these filters and faucets is straightforward and follows similar processes for filters joining the main water faucet. Stainless steel found in kitchens is the most suitable as they are easy to cut, unlike ceramic sinks in bathrooms that can easily shatter.