What Is the Thing Next to My Kitchen Faucet?

Updated: Oct. 07, 2021

You're not the only person to ask this question.

Even when you’ve owned your home for decades, there are some features that make you think, “What in the world is that?” Don’t worry—it happens to all of us. People wonder about strange little doors in old houses, that random toilet in the basement and other odd fixtures.

So. What is the thing next to my kitchen faucet? I found the the answer with help from some friendly Redditors.

What Is That Metal Thing?

The metal thing in question is a small, cylindrical metal tube that sits next to the faucet on your kitchen sink. Reddit user @dominostracker wondered the exact same thing, and according to a few wonderful human beings who took the time to answer, that thing is an air gap. It helps prevent dirty water from the dishwasher flowing back through the pipes and contaminating the clean water.

Don’t miss our full list of old home features people ask about. It covers oil tanks in the basement, buttons in the floor and more.

How an Air Gap Works

It’s exactly as it sounds—a literal gap of air in the line that prevents dirty water backflowing into the fresh water. If you ever notice water coming out from underneath the cap, it may be due to possible debris. You can troubleshoot that problem with here.

Taste of Home
Originally Published on Taste of Home