Reverse Osmosis Air Gap Bypass How-To Guide

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Air gap reverse osmosis faucets do tend to run a little noisy.

If the sound is driving you crazy, good news, there is a way you can silence it!

All it will take on your behalf is a pair of scissors, a few materials, and a little patience—no need to buy an entirely new non-air gap RO faucet just for a quieter option.

So, here is our handy ‘how to’ guide for bypassing your reverse osmosis air gap and possibly saving your sanity.

Key Takeaways

Here is how to bypass a reverse osmosis air gap:

  1. Shut off the water supply to your reverse osmosis system as well as the storage tank valve, and drain the RO faucet.
  2. Remove the drain tubing that connects to the faucet base.
  3. Replace/convert your ⅜ drain saddle with a ¼ inch one.
  4. Trim your RO system’s wastewater line so that it has the ideal length to connect directly to the drain saddle.
  5. Cut the wastewater line far away from the drain saddle (around 12 inches) to install a check valve.

Reverse Osmosis Air Gap Bypass – How It’s Done

  1. Shut off your water supply and RO storage tank valve, and drain the faucet of any remaining water.
  2. Remove the ⅜ inch drain tubing (2 water lines) that connects to the faucet base.
  3. Install a new ¼ inch drain saddle or use an adapter to convert your old ⅜ inch drain saddle.
  4. Cut/trim the wastewater line coming from the reverse osmosis system as needed.
  5. Connect the wastewater line to the new ¼ inch drain saddle.
  6. Cut the wastewater line around 12 inches from the RO unit itself and install a check valve. You don’t want it to be close to the drain saddle.
  7. The permeate line from the storage tank will remain connected to the center faucet stem, and it is the only one that will stay connected to the faucet.

Get a Check Valve!

A check valve is a device that will prevent dirty water from getting into the reverse osmosis system if there is a clog in your drain pipe. It is a standard component of any RO system that doesn’t use an air gap faucet. It is also known as an air gap adapter.

woman sitting in front of water glass

Why Bypass an RO Faucet Air Gap?

The great thing about bypassing a reverse osmosis faucet air gap is that it eliminates most of the disadvantages that come with an air gap faucet:

Noise Silencing

Air gap faucets can be super noisy. By bypassing the RO faucet air gap, you will have a quieter system overall.

Stops Water Flowing onto your Sink or Countertop

The water lines in an air gap RO faucet are pretty narrow, and sediment and debris can build up and block the drain line. If this happens, water will flow from the air gap and onto your sink/countertop.

What’s an Air Gap RO Faucet and What Is Its Purpose?

An air gap RO faucet is a specialized faucet that is designed specifically for use with an under sink reverse osmosis system. It may even be a requirement to have one if you have an RO system, depending on the plumbing codes in your area.

An air gap faucet contains three tubes that run up the faucet stem; one carrying the filtered water for use, one carrying the wastewater up the stem and past the air gap, and a third line where the wastewater uses gravity to drop down for disposal via your sink drain pipe.

The purpose of the air gap faucet is to make sure that if your drain pipe clogs, your RO system will pull air back into the unit and not contaminated water, which could jeopardize your RO membrane and health.

Could I replace an Air Gap Faucet with a Non-Air Gap Faucet?

Check to see if your local plumbing codes require you to have an air gap faucet with your RO machine. If not, then yes, you can replace your air gap reverse osmosis faucet with a non-air gap faucet.

To do this, you may need to get an adapter as air gap faucets use a different size tubing to connect to the drain saddle than non-air gap faucets. The adapter is required in order to fit the 3/8” drain saddle connection to the ¼” drain line.

If you have any questions about bypassing a reverse osmosis air gap please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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