How To Install Reverse Osmosis System Under Kitchen Sink?

In order to install your reverse osmosis system, you need to understand how your reverse osmosis system works. Your reverse osmosis system consists of twelve different parts.

These are:

• RO Module
• Angle Stop Valve
• Melt Brown Polypropylene Filter (Pre-Filter #1)
• Carbon Pre-Filter (Pre-Filter #2)
• Automatic-Shut-Off Valve
• Reverse Osmosis Membrane
• Carbon Post Filter
• Bladder Tank
• Drinking Water Faucet
• Drain Clamp (Waste Water Saddle Valve)
• Tubing
• Quick-Connect Fittings

Overview

A reverse osmosis system can be installed after drilling a hole into granite on your kitchen skin. As you can see, your reverse osmosis system contains a drinking water faucet. You need to install the drinking water faucet on your kitchen granite countertop. You need a hole for that.

under Kitchen Sink Installation

You may need certain tools to install your reverse osmosis system on your kitchen sink. Many kitchen owners do not have a hole for the reverse osmosis water faucet. If you are lucky enough to already have a suitable hole for your reverse osmosis water faucet, you do not need to follow step #1.

Step #1: Make a hole for the drinking water faucet

You need the following tools to drill a hole in the granite countertop of your kitchen sink:

• 3/8” Variable Speed Electric Drill (You can use one with stainless steel and 2,500 RPM)
• 1/8”, 1/4” and 1/2” Metal or Concrete Drill Bits
• Phillips Head Screw Driver
• Hammer
• Center Punch

You need to drill a pilot hole first. You should not use your diamond-tipped hole saw to drill the pilot hole. You can keep the drill cool through tap water.

Please remember that you do not need to wash your drill. It is an electronic device, and you do not want to experience an electric shock or device malfunction.

After drilling the pilot hole, you can use the diamond-tipped hole saw. Keep your drill cool by spraying the water onto the hole. Make sure your hole is neat and clean for the drinking water faucet. Your hole is now ready.

Step #2: Mount the drinking water faucet onto the hole.

Take out your drinking water faucet and look at it. You will find the following parts on your drinking water faucet:

• Chrome Base Plate
• Rubber Washer
• Metal Washer
• Lock Washer
• Hex Nut
• Threaded Shank

Check the hole by mounting the drinking water faucet onto the hole. You can mount the drinking water faucet to the hole by putting the threaded shank into the hole and adjusting the drinking water faucet manually.

You have to work below your kitchen sink. Adjust the lock washer, and at this stage, you can put on the hex nut. Try not to damage the stainless steel parts of your drinking water faucet.

The drinking water faucet can be connected to the connector pipe through the faucet connector. You connect the faucet to the drinking water faucet by using an adjustable wrench.   

It is important for you to properly adjust the drinking water faucet. I always ask someone to hold the faucet for me while I tighten the hex nut from below the sink.

I tighten the hex nut but do not completely tighten it. I then tighten the drinking water faucet from above the sink. This way, I ensure that my drinking water faucet is in a suitable position.

Step #3: Attach the feed water tubing to the cold water supply line.

Check your cold water supply line. Make sure that it is working. Now, install the Angle Stop Adapter to your existing cold water supply line.

The Angle Stop Adapter Valve will segregate and supply cold water for your reverse osmosis system. In plain words, the Angle Stop Valve supplies water both to the existing water faucet and the drinking water faucet of your reverse osmosis system.

The Angle Stop Valve can be connected to the following:

• The Existing Faucet
• Cold Water Shut Off Valve
• The Reverse Osmosis System

It enables you to turn on and cut off the cold water supply to your reverse osmosis system. You can use your adjustable wrench to install the Angle Stop Adapter Valve and connect it to the feed water tubing. Some people also use the channel lock plier to install the Angle Stop Adapter Valve.

Step #4: Set up your drain saddle valve.

Why do you need a drain saddle valve? The drain saddle valve is going to move the wastewater to your sink’s drain. It develops the connection between your reverse osmosis system and your kitchen’s drain.

The drain saddle valve of your reverse osmosis system is suitable for the 1-1/2” OD drainpipe. It does not matter whether you have a vertical or a horizontal drain under your kitchen sink. The drain saddle valve is supposed to be positioned before the p-trap.

It is best practice to avoid installing the drain saddle valve near the garbage disposal as it makes matters worse. You do not want to have a clogged drain or something like it.

Follow these simple steps to install your drain saddle valve:

• Select a suitable area for your drain saddle valve.
• Make sure that you have a ¼” hole on the pipe.
• Apply adhesive to the sides of the hole.
• Adjust the drain saddle valve over your drain pipe.
• Check the position of your drain saddle valve and make sure that it is tightly clamped. (Avoid overtightening the nuts and bolts, and do not leave any uneven space)

Step #5: Set up your under-the-sink tubing connections.

Make sure that you have set up under the sink tubing connections at this stage.

Step #6: Set up your Reverse Osmosis Cartridges.

Use gloves to set up your reverse osmosis cartridges. You can install the sediment cartridge and the carbon block cartridge. The first space on the inlet side is for your melt brown polypropylene sediment cartridge. The second space is for your carbon block cartridges.

You can connect the reverse osmosis membrane to your Reverse Osmosis System. There is a membrane housing in your reverse Osmosis system. You can install the reverse osmosis membrane in the membrane housing. Insert the o-ring end of the reverse housing membrane in the membrane housing.

Step #7: Mount your Reverse Osmosis Unit.

Select a suitable space for your reverse osmosis unit. It can be installed on the left or right side of the sink sidewall. Make sure that your reverse osmosis unit is not touching the floor. It should be at least 2” above the floor.

Some people let their reverse osmosis system sit on the floor because they do not have solid sidewalls near the kitchen sink. It is OK as long as your reverse osmosis unit remains safe.

Use a pencil to mark holes for your reverse osmosis unit. Drill the holes and set up the mounting bracket. Please ensure that you properly tighten the screws at this stage. Mount your reverse osmosis system so that it may not fall down.

Step #8: Install your Pre-Fill and Supply Tank.

Establish a connection between the feed line of the RO unit and the bladder tank by using a 3/8” x 1/4” reducer. You can check for leaks at this stage. Turn off the feed pressure, and let the tube move out of the reducer. You can remove the reducer too.

Pre-pressurized tanks with a 7 psi are placed under the kitchen sink during this stage.

Step #9: Make the last tubing connections.

Make sure that you have used the right tubing length. Check that your tubing connections are in good shape and have a smooth flow of water.   

Install whole house reverse osmosis system

The first step towards the installation of a whole house reverse osmosis system is identifying the problem. That is, you have to determine the existing water quality, and you are going to determine your water needs and requirements. The water needs and criteria may differ from person to person.

 It is always a good idea to perform water analysis before installing the whole house reverse osmosis system. Water analysis, also known as the water quality test, is an important step. Your water analysis will tell you the exact psi range you need to set your system at.

A water quality test is an essential step to install whole house reverse osmosis system because it tells you about your required levels of water purification.

Let’s take a look at your whole house reverse osmosis system so that you may know how to install your whole house reverse osmosis system:

• Identify your water supply line. (Make sure that your water supply line is working)
• Identify your water outlet line. (You do want any leakages in your water outlet line)
• Place your whole house reverse osmosis system and the water tank near the water supply line and the water outlet line.
• Identify the water inlet inside the whole house reverse osmosis system. You will have to connect the water supply line to the water inlet housing in your whole house reverse osmosis system.
• Take a look at your whole house reverse osmosis system, and you will see the hoses.
• During the installation process, you will connect these hoses to the top of your water tank.
• You will notice an outlet at the bottom of your water tank. This outlet will eventually be connected to the re-pressurization pump. The re-pressurization pump creates water pressure for your house.
• If you look at the re-pressurization water tank closely, you will notice that a pipe connects the re-pressurization tank to the UV filter.
• The outlet of the UV filter will eventually supply water to your house.

I use PVC pipes to install whole house reverse osmosis system. It depends on your pressure ratings, my pressure ratings are OK, and the rubber pipes just freak me out. You need a number of fittings, unions, joints, and pipes to install whole house reverse osmosis system.  

Let’s get started.

Step #1: Prepare and connect the water supply lines.

Start with the water outlet on your UV filter. Install the slip joint and the slip union on your water outlet. Now, connect PVC pipe. Your PVC pipe should be connected to the rubber pipe for your house’s water supply.

You can connect the water supply of your whole house reverse osmosis system. It does not matter whether you glue the water supply lines first or the water tank. I connect the water supply lines first.

Step #2: Prepare and connect the water tank.

You will have to connect the flexible drain line to the sump pump. It helps you drain the excess water. Make sure that your water tank is at a proper height relative to your re-pressurization pump. If you do not keep your water tank at a suitable level, you will lose approximately 20 gallons of water.

Step #3: Install the float switch inside the water tank.

Make sure that your water tank is clean before you install the float switch. You can vacuum the water tank. You can check the length of your float switch’s cord. Make a hole for the wires at the top of the water tank. Pass down the float switch cord into your water tank.

Make sure that your float switch is properly installed. You may want to adjust the length of your float switch cord. You may do so as you deem fit. I do not want to mess it up.

Sometimes you need to check the quality of your float switch. Make sure that you get the right float switch to install your whole house reverse osmosis system.   

Step #4: Connect the water tank and your whole house reverse osmosis system through the pipeline.

You can cut and adjust the length of your pipeline. Just make sure that it does not leak. You can put the lid back on your water tank so that dirt may not enter your water tank.

Step #5: Setup the electrical connection.

Your whole house reverse osmosis system needs a reliable electrical connection to operate. You will have to identify and differentiate the wires from one another. The company zip-ties the cords, so you will have to unzip them.

Step #6: Install the anti-scaling tank.

If you have a hard water issue in your area, you can install the anti-scaling tank. You can use your wrench, drill, and screwdriver to install your anti-scaling tank.

Step #7: Install your UV filter.

Make sure that your UV filter is in place before you try to run and check your whole house reverse osmosis system for water leaks. Do not touch your UV filter directly by using your bare hands. You can use cotton gloves to handle the UV filter.

Do not forget to put on the O-ring and the cover to secure your UV filter. Do not over-tighten the cover of your UV filter. You will have to put the stainless steel spring inside the top cover of your UV filter housing.

Step #8: Check your whole house reverse osmosis system for water leaks.  

Turn on the first side of your water supply to check your whole house reverse osmosis system for water leaks. Make sure that your pipes and quick fittings are dry. You do not want to see water leaking on the floor.

Be patient. Because the whole house reverse osmosis system takes more water and time to fill up.  

Step #9: Install the UV lamp.

Do not touch the UV lamp with your bare hands. Put the UV lamp inside the UV filter housing. Connect the cord to the top of your UV filter housing. You can use your screwdriver to install the wires.

Step #10: Ensure that all of your filters are ready.

Take a look at the reverse osmosis system, and you will find a gray filter. Take out the gray filter, fill it with water, and put it back on. This might seem messy, so try not to spill too much water.

You can turn on the second side of your water supply now. Again, check your system for water leaks. Make sure that your gray filter is not leaking. It may take five to ten minutes.

Pro-tip: Check the air bubbles and your pressure gauges. Let your anti-scaling tank fill up.

You can run your whole house reverse osmosis system now. Run a quick test of your water. You will notice a considerable change in the pH levels of your water. Your whole house reverse osmosis system is good to go.

Pre-Installation :

RO System Under Kitchen Sink Check List

• Make sure that you have drilled a hole for the drinking water faucet before you install a RO system under the kitchen sink.
• Make sure that you have a working cold water supply under your sink.
• Check that your kitchen drain is not clogged before you install the RO system under the kitchen sink.

Installation Steps:

Post Installation Instructions Reverse Osmosis system:

You can conduct a quick water analysis after installing your Reverse Osmosis (RO) system under the kitchen sink. Your water analysis will reveal the pH of your drinking water. You can use a TDS meter to check the water quality.

You need to check the TDS reading of the raw water and the TDS reading of your drinking water. You can now calculate the TDS efficiency of your reverse osmosis system by using the following formula:

RO efficiency= {(Raw TDS – RO TDS)/Raw TDS} x 100

Generally, a five-stage reverse osmosis system can give you 80-97% TDS efficiency.

Reverse osmosis leaking under sink

A reverse osmosis system leaking under sink can be annoying. Water leaking under the sink creates a lot of mess. You do not want to see reverse osmosis leaking under sink. If you happen to see a reverse osmosis system leaking under the sink, follow the following measures:

• Shut off your water tank. You need to turn the handle on top of your RO water tank to shut it off. There are two other ways to shut off the RO water tank. You can use the original angle stop valve handle or the handle on your supply membrane. You will have to turn the angle stop valve handle at least five to six times to turn it off.
• Open the drinking water faucet until no more water comes out.
• Use a towel to wipe all the dampness and all the drains of your RO system under the kitchen sink. You will know whether the drains of your RO system are leaking or not.
• Check the system for leaks. Notice if there are any other clogged drains and fix them.  

cost:

A reverse osmosis system can be available in a wide cost range. It actually depends on the type of your reverse osmosis system. There are other factors that affect your RO system’s cost. Some of these factors are:

• Built quality
• Level of filtration
• Durability
• Fittings quality
• Filters quality
• Filters replacement
• Mineral re-addition in water

You have to know your own needs before selecting the right reverse osmosis system. Different forms of RO systems are designed for different purposes and usage. Generally, people want a high-quality reverse osmosis system. You should look for a system between $500-$1500.

The whole house reverse osmosis system can cost more. You should look for a commercial-grade reverse osmosis system in the $1000-$20,000 price range. Reverse osmosis system installation cost varies from area to area.

Reverse osmosis system installation cost depends on the following factors:

• Type of your reverse osmosis system
• Water softener
• Water taste that you want
• Required water odor
• Your status in the buying process (Planning stage or Buying stage)
• Timing of your request
• Location (Home or commercial property)

The labor cost to install reverse osmosis system varies according to your location. It means the labor cost to install reverse osmosis system in New York will be different from the labor cost to install reverse osmosis system in Michigan.

Key Take Aways | How To Install Reverse Osmosis System Under Kitchen Sink?

• Reverse osmosis system needs a working water supply.
• You have to conduct water analysis before you decide to install a reverse osmosis system.
• The whole house reverse osmosis system needs a good working space.
• Depending on the type of your reverse osmosis system, you may have to change the filters once or twice yearly.
• Always measure the TDS of your water after installing the reverse osmosis system.