Reverse Osmosis Installation Guide: Simple Steps to Clean Drinking Water

ro install

So, you have determined to add a reverse osmosis water filter system in your house since you don’t need to be subjected to nasty water contaminants anymore.

You found a terrific model online and bought it a few days ago. This morning, the machine came in a large, heavy box. You opened the package to have a first look and…

Wow, you did not expect the system to get that many unique parts. Hopefully, you can set up everything correctly. After all, you aren’t a trained plumber. However, considering the costs of hiring a professional, it is a priority for you to perform the installation yourself.

Don’t worry, we have got you covered! This guide has all of the information you will need for a trouble-free installation.

RO System Installation Diagram

ro install

We have made this RO system setup diagram to illustrate how the individual parts should connect.

Where To Install

Installing below the kitchen sink is the standard, albeit not necessarily the most convenient solution because of limited space. Options are the garage, basement, or a utility area, installing a water line into the kitchen sink.

What is important is that you install it on a cold-water line downstream of any other water treatment unit, such as a softening system. Also, do not put in where freezing temperatures may occur.

How To Install a Reverse Osmosis System?

It’s time for you to understand how you can hook up your new reverse osmosis under sink system. With a small preparation and the necessary tools, it is not that hard to pull off.

Also, every system should have detailed installation instructions. If this is not enough, you will find loads of useful videos on YouTube.


It might be too late, but you need to ensure that there’s sufficient space under your kitchen sink to accommodate a filter module before buying an RO system.

Furthermore, you will need to be sure that there is a cold-water line that you can use as your feed source (which is almost always the case).

Once the system is delivered, unbox it, and double-check that all components fit in their preferred location. This way, you know whether you will need to make alterations to plumbing, etc., before beginning with the installation.


Gather all the necessary tools and components ahead. Having everything lined up can save you from lots of frustration. The given list does not claim completeness:

  • RO system setup manual
  • RO module
  • Water storage tank
  • Faucet
  • Filter cartridges + RO membrane
  • Installation kit including filter wrench, colour-coded piping, stop tank, tank valve, drain saddle, faucet connector, 
  • Power drill
  • 1/4″ (⅜”) (1/2″) drill bit (size depends upon faucet kind used)
  • Utility knife
  • Tubing cutter
  • Adjustable wrench
  • Towel
  • Screwdriver

1. Faucet Installation

ro install

Let’s begin by installing the reverse osmosis faucet, which will soon offer you clean, good tasting drinking water.

First of all, you want to choose where you wish to install it unless your sink currently has an excess hole you wish to use (it might be dealt with by a chrome-plated). If not, you must drill a new hole in the countertop or sink. The faucet should be positioned with ease in mind. A set area is required.

Please note: You may take a different kind of drill bit to avoid scratching or chipping based on the material.

Mark the spot with a center punch. Then smoothly grind off sufficient surface material to safely include the 1/4″ drill bit. Then carefully drill a hole and go extra slow once you’re going to hit any alloy (a drop of oil can work wonders). To get a ⅜” or 1/2″ hole, drill a 1/4″pilot hole.

When you’re done, remove any residual metal chips which could damage the surface and clean up sharp corners.

Put the faucet stem through the hole and tighten it in the bottom with washers and a hex nut. Then join the quick connect fitting and secure with a wrench.

Hats off, you’ve just finished the most demanding task!

2. Installing the Drain Saddle

The next step would be to set up the drain saddle, a.k.a. drain line adapter on the drain line.

The saddle/adapter should be placed over and as far away as possible from the dishwasher release and trash disposal to prevent clogging and safeguard your RO system from potential contamination and fouling. What is more, it must be at least 6″ over the p-trap.

Drill a 1/4″ hole at the top of the side of the drain line (not the bottom). Tighten the drain clamps with bolts, adjusting the clamp hole with the hole in the tube. Take care not to overtighten.

3. Feed Valve Installation

In step three, we will set up the inlet feed valve that connects your reverse osmosis system into the cold-water line.

First, turn off the cold and warm water supply. If valves are not working, shut off the whole water to your dwelling. Then put the pressure in the water channels by opening various outlets. Remove the tube from the cold-water valve. Install the new feed valve (adapter may be required) and tighten it with a wrench. Be sure that you shut the feed valve for the time being.

Connect the cold-water tubing into the valve (adapter may be required) and turn the water supply back on.

4. Water Storage Tank Setup

ro install

You want to set the water storage tank within 10 feet of the drinking water faucet not to lose substantial pressure. (Remember that, depending on its size, the tank may weigh more than 25 pounds when filled to the top.)

Before placing it in position, wrap around six Teflon tape layers around the threaded interface on top. Then screw on the tank valve or tank connector. They ought to thread on easily and have to be hand-tight.

With particular systems, the storage tank will be all set on its side without undermining filtration performance. This is useful if you do not have a lot of room in your kitchen cupboard.

5. Mount + Connect RO Module

When mounting the RO module, which is optional, consider that you’ll want to change filters and possibly perform other maintenance jobs every once in a while. To put it in other words, there has to be sufficient space beneath the system.

To join the module, we use colour-coded piping. Most systems include quick-connect fittings. Just push the tubes in their various fittings as far as they will go. 

It is possible to test a connection by trying to pull back gently.

Water residue in the tube means that the manufacturer tested the machine. Keep a towel at the ready!

Yellow feed water line:

  1. Push the yellow supply line on the previously installed feed water valve on one end (tighten the nut a half turn beyond hand-tight).
  2. Connect the other end into the feed port of the RO module.
  3. If required, cut the line so that it doesn’t kink.

Freshwater tank lineup: Connect the green line to the tank valve and the filter system’s outlet port.

Black drain line: Connect the black cable to the drain saddle and the RO module’s flow restrictor. Cut the line so the water can flow downhill without loops.

Blue faucet supply line: Connect the blue cable to the RO faucet’s quick-connect fitting and into the post-filter outlet port.

Pro tip: Trimmed connections will enhance water flow. At precisely the same time, extra tubing might be convenient if the system ever has to be relocated.

6. Filter + Filtration Setup

ro install

Insert the numerous pre-filters and the RO membrane in their housings according to the directions provided:

for those pre-filters, remove the filter casing, insert the filter and then screw the housing back with all O-rings set up. Carefully tighten with the filter wrench.

For the RO membrane, eliminate the housing cap and carefully push the cylinder to the socket until ultimately in. Then put the lid back on while ensuring that any O-rings sit tight.

Typically, the first filter is a sediment pre-filter, followed by carbons pre-filter(s),) and lastly, the membrane. Then come the post-filters.

7. Starting the System

Ultimately, it is time to start your new reverse osmosis system. Here is the way:

  1. Open the RO faucet and the feed water valve but maintain the storage tank valve closed. You may hear gurgling noises. This is just air leaving the machine.
  2. Check all connections for leaks. Our RO troubleshooting guide might help.
  3. After around 10 to 15 minutes, water will begin to dribble from the dispenser — do not worry if the initial trickle of water has a dark colour. These are simply carbon fines being flushed out. Close the tap and open the storage tank valve to enable the tank to fill.
  4. Filling the tank will take anywhere around 3 to 10 hours, depending on the incoming water’s pressure and quality. Whenever it is full, you may no longer hear water flowing down the drain. This is when you must start the drinking water faucet to flush the entire unit.
  5. After the water is again down to a dribble. The storage tank has cleared. Close the faucet and allow the tank to refill.
  6. Flush another time by opening the faucet.

Some makers recommended flushing a new system 2-3 days before use. As soon as you’ve done the installation is complete, and your water is ready for drinking.

Calling a Professional

Not everyone feels confident installing an RO system on their own. If you, too, choose to turn to a specialist, we urge you to contact a local plumber in your area.

How much the setup will cost depends first and foremost on the sort of system you wish to have installed:

Countertop system, free: Reverse osmosis countertop units, is highly portable and can be fitted to and taken out from a standard kitchen faucet within minutes. No installation is required. learn more

The under-sink system, Prices: $150-USD 400 — As we’ve seen, standardized under sink systems need proper installation — something that you can do yourself in 1-2 hours if you’re technically skilled. The outsourcing prices should range somewhere between $150 and USD 300, possibly up to USD 400 in particular circumstances.

Whole house system, Prices: USD 500+ — It is tough to estimate the cost for installing full house RO water purifier systems since they’re usually more complicated. Also, additional supplies such as tubing and valves, add to the prices. A few hundred around USD 500 is just about the bare minimum. Again, speak to contractors or technicians in your area. And if you’re looking for a whole-house system to add to your house.

If you don’t have a plumber in your mind, whom you trust, reading out local reviews on the internet is an excellent starting point. Some popular websites you can use are:

Asking for estimates from more than one plumber will probably save you a great deal of cash. Let them know that you’ve already bought a system but need help with the setup. Seek their experience and references.

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