How to Install a Reverse Osmosis System in Your Home

**Articles may contain links that I earn compensation for if clicked and you make a purchase. As an Amazon Associate, I earn from qualifying purchases. These earnings do not actually impact the price of the product or service.

A Reverse Osmosis (RO) System Installation can seem really difficult since it has a lot of steps, but it is actually quite doable for most DIYers. There are quite a few parts and instructions, but it is completely safe to attempt at home. It can save you the cost of installation, since RO systems can get quite pricey. It is also a great skill to have when you need to replace your system. Especially with those that work on home improvement projects, this will be a breeze for you. For those that don’t, do not worry. We have laid out a detailed guide to help filter out some of the confusion for you. With this, you will learn about the different components and steps to help you feel more comfortable tackling this project.

Components of the System

An RO system is composed of many different parts that help to filter your water. Before you install your system, you should get familiar with the different parts of an RO system, so it is easier to set up. Different RO systems have slightly different parts, especially a tankless vs. a tank system. The main components are the same since they work in the same manner to filter out impurities. The main components of an RO system include:

  • RO Module (main)- This part is the body of the system that encompasses all the filters and membranes. It usually comes with a bracket depending on the type of mount it offers.
  • Angle Stop Valve- This part is what connects the supply water to the entire system. The valve allows you to easily shut off the water supply if you need to switch the filters or complete other maintenance.
  • Pre-Filters- The pre-filters usually work to filter out some of the larger impurities such as dirt or sediment. Some systems have more than one pre-filter that filters out other elements such as chemical contaminants.
  • Shut-Off Valve- The shut-off valve is usually automatic and activates when the storage tank is full. The system saves energy and water when the valve is shut off.
  • RO Membrane- The RO membrane is the semipermeable thin composite that helps to capture the harmful compounds. This part is usually the main component that filters your water.
  • Post Filters- The post-filters are what the water passes through after going through the RO membrane. They help to further purify the water and work to remove odors or odd tastes.
  • Bladder Tank- This is the part that holds the purified water making it readily available whenever you need it. Tankless models do not have a bladder tank.
  • Water Faucet- This part is what dispenses the purified water. Some models have indicators such as an LED light that let you know when the RO system is being used.
  • Wastewater Saddle Valve- This valve connects to the drain that removes the contaminated water.
  • Tubing and Fittings- The tubing and fittings are what connects all the different components together. Make sure that when installing, these components all fit together tightly to prevent leaks.

Tools You Will Need

Depending on the type of system you have, the tools will vary slightly. Always check your manual for a more detailed list before you begin. Some main tools that are necessary for installation include:

  • The Best RO system for your specific needs
  • Variable Speed Electric Drill
  • Metal Cutting drill bits (check the manual for sizing)
  • Concrete drill bits (only for some sinks)
  • Screw Driver
  • Adjustable wrench
  • Teflon Tape
  • Plastic Tubing cutter
  • Hammer
  • Center Punch


The location of your RO system depends on what type you have and what you will be using it for. Smaller units are installed under sinks or kitchen appliances. Larger units are usually installed in the basement or where the water comes into the house. Make sure not to install it somewhere where the system is exposed to freezing temperature. This makes sure the system can run smoothly.

Faucet- This should be placed on a flat surface near the sink where you need the water. It can be mounted if there is no hole available. Make sure the surface is not too thick, or you will need an extension.

Tank- The tank can be placed anywhere within ten feet of where you place the faucet. Usually, people choose to place it under the sink in the cabinet and out of the way. Some tanks are heavier, so make sure that it is secure.

Unit- The main RO unit can be mounted anywhere, depending on the system. Most come with brackets to fit on the sink or in the back of the cabinet. Make sure that you can access it easily so you can easily reach it for occasional maintenance.

Angle Stop Valve- Try to keep this component close to the RO unit since it connects the water to the unit.

Drain Saddle Valve- Connect it to the drainpipe but away from the garbage disposal to avoid clogging. Make sure to install this part before the horizontal tailpiece to avoid collision.

Installing the System

Before beginning, always check the state and local plumbing codes. Some areas are stricter than others and have certain standards that need to be met. You do not want to do all this work just to find out that installation needs to be done by a licensed plumber.

Step 1: Install the Faucet

If there is no faucet mounting hole present, you can drill your own hole. A 2 in. flat surface is needed to mount the faucet. Make sure to check the bottom before drilling down. You want to position this so that the water flows freely into the sink. For certain sinks, there are certain tools and precautions to ensure that there is no chipping of the material. The main procedures for mounting the faucet are:

  1. Use the center punch to mark the center for the hole
  2. Drill the hole with a concrete drilling bit slowly (porcelain sinks)
  3. When you see metal, switching to metal cutting bits and keep drilling
  4. Enlarge the hole until it reaches ½ in.

If your sink has a hole for the faucet, you can skip this step and mount the faucet. Start by disassembling the hardware from the shank. Feed the shank through your drilled hole and position the faucet to your liking. Fit the washer and hex nut over the shank from under the sink. Tighten with the wrench while holding the faucet from the top.

Step 2: Install the Valves and Tubes

These help to shut off the supply water to the system.

  1. Start by turning off the water supply, then turn on the faucet of the cold water supply on your sink.
  2. Disconnect the riser tube from your cold water shut-off using an adjustable wrench.
  3.  Connect the Angle Stop Valve that comes with your system onto the cold water shut-off. Reconnect the riser tube to the other side of the valve and tighten.
  4. Connect the length of tubing you need to connect the valve with the rest of the unit.

Step 3: Install the Drain Saddle Valve

  1. Determine the location that you want to drain the saddle valve and mark for accuracy before drilling a ¼ in. hole.
  2. Place both sides of the saddle valve on the drainpipe to align with the hole.
  3. Use the nuts and bolts to tighten and secure the saddle clamp.

Step 4: Install the RO Component

Make sure to wear gloves or make sure that your hands are clean before beginning.

  1. Follow the manual to see which filters go in first. Most of the time it will be a sediment filter followed by a carbon block, then the RO membrane.
  2. Push the RO membrane completely into the housing with the O-ring end on the inside.

Step 5: Install the Unit

To do this, simply mark the location of the holes before drilling.  Make sure that it is at least 2 in. away from the floor. Use the brackets and screws provided to position the unit.

Step 6: Install the Tank

  1. Pre-fill the water tank by connecting the feed line. Check if there is adequate pressure and check for any leaks.
  2. Place the tank within 10 feet of the RO unit.
  3. After the tank is filled, shut off the tank valve.

Step 7: Connect the Tubes

  1. Now that everything is in place, cut the tubes to the desired lengths, and make sure there are no kinks.
  2. Make sure to keep the shortest length possible to ensure efficient flow.
  3. Connect the drain lines to the main unit.

Step 8: Start the System

Before beginning, make sure to check that all the fittings are tight to avoid leaking.

  1. Open the valve to let the system start to pressurize.
  2. Open the bladder tank valve.
  3. Turn on your faucet until you see the running water.
  4. Turn off the faucet and monitor for at least five minutes to see if the system is leaking.
  5. Let the system do its thing.

Final Tips

It may seem like a large number of steps, but hopefully, this guide can help you install your own RO system. The main thing to remember is to check your local ordinances before beginning. Also, always check the manual to see if there are any specifications you need to make. Installing your own system can save you money on installation costs and can be a great project for the family. You will get purified water in your home in no time at all.