The logo of adu contractors, indicating they specialize in damage repair services related to water, fire, mold, and storms.
Why Does My Kitchen Sink Drain Keep Leaking? 7 Main Reasons

Why Does My Kitchen Sink Drain Keep Leaking? 7 Main Reasons

For homeowners, water in places it shouldn’t be is never a good sign.

The sight of water constantly leaking from your kitchen sink drain raises an instant alarm—and for a good reason. Repairing or replacing fixtures in your home can be incredibly costly. But the longer you wait, the higher risk of water damage to surrounding areas and the greater chance you’ll meet an unexpected flood in your kitchen.

Before you call in the professionals, why not see if you can troubleshoot the issue yourself? Identifying the cause of the leak is the first step.

With this guide of why your kitchen drain sink may be leaking, you can help keep water in the drain where it should be.

Read more: How to fix a leak under the kitchen sink

Old Drain Putty

Not everyone feels competent at wielding tools to fix household fixtures, but the source of your leak may not require tools to fix at all! One common reason kitchen sink drains tend to leak is that the putty is old.

Plumber’s putty seals drains to hold pipes together and prevent leaks. This putty can wear and become thin or brittle as time goes on. Replacing the putty on your sink is an easy first step to troubleshooting the issue.

Read more: How to fix pipes under sink

Leak Around the Faucet

If you notice water pooling around the base of the faucet when you turn the sink on, this is a sign that the source of the leak may not be in the cabinet below but right in front of you.

You likely need to change the gaskets or replace some washers to ensure that water flows correctly without spilling out onto your counter.

Read more: What causes a dripping faucet

Water Supply Connection is Loose

If you’ve ever been washing dishes by hand and suddenly there’s a puddle of water at your feet, there’s a strong chance you’ve dealt with a loose water supply connection. Water is supplied to your kitchen sink system from underneath the sink. Because this is often a cabinet where other household items are stored, a significant leak could do substantial damage to belongings and will be a nightmare to clean up.

When any connecting components are loose, you may notice a constant leak. To fix this, tighten or replace the necessary parts, like the coupling nuts or gasket. Because this is out of sight most of the time, it’s essential to check the equipment under your sink from time to time to ensure everything is tightly sealed and in working order.

Plumbing Pipe Wrenches

Clogged P-Trap

This issue may be hard to spot at first since it’s out of sight. If you can’t identify where a leak stems from, the P-Trap is a likely answer.

While you may never have heard of a P-Trap, you most likely have one below your kitchen sink. A P-Trap is a bent drain pipe shaped like a P that serves as the connection between your sink’s drain and your septic tank or sewer system. It helps prevent foul-smelling and potentially dangerous gases from sneaking back through the drain into your home.

Over time, this pipe can become clogged with debris from your sink, such as food scraps, causing it to leak. When this happens, you’ll need to unclog and clean the pipe. If you notice any corrosion on the pipe, it is best to replace it to prevent further leakage.

Corrosion of the Valve Seat

Another common reason your kitchen sink could be leaking is that the valve seat has corroded. The valve seat is the piece that connects the spout and the faucet.

A survey in 2019 showed that the most common type of home repair was for plumbing issues. While there are moments to call a professional plumber for assistance, there are many issues you can tackle on your own and even more steps you can take to prevent leaks from occurring. Valve seat corrosion is avoidable by simply keeping the valve seat clean.

O-Ring is Worn Down

The O-Ring is a mechanical gasket that holds the faucet’s stem securely in place. It is sometimes called a packing or a toric joint. Essentially, this loop of elastomer is designed to sit in the groove under the faucet stem. The O-Ring forms a tight, leak-proof seal as the pieces are compressed together.

Over time, the O-Ring can wear down and therefore doesn’t serve as an effective seal. If you notice leakage in this area, it may be time to replace your sink’s O-Ring.

Worn Out Washers

One of the most common causes of a leaky sink is a worn-out washer. That’s because every single time you turn on the faucet, a washer presses against the valve seat of your sink. Over time, this repetitive tension can cause the washer to erode. By the time you notice water pooling around the spout, the washer has far surpassed the point of no return.

Luckily, this is an easy fix. All you need to do is replace the washer, and you should be back to a leak-free sink in no time.

A man stands beside a pickup truck labeled "Licensed General Contractor," holding a black case. The truck, adorned with an American flag design, is parked in front of a Texas home, ready to address a roof leak repair.


Each year, households in the United States lose immense amounts of water to leakage: a sum equivalent to the water use of approximately 11 million homes. This startling statistic is hard to comprehend, considering how little water appears to leak with every drop from a damaged kitchen drain. With knowledge of why leaks may be occurring, you can do your part to put an end to water waste.

Need some help? We’ve got you covered. All Dry USA has over a decade of experience in water damage remediation and more. Our friendly team of experts will help you clean up the aftermath that leaks have caused and put an end to the problem for good.

Reach out today!


Before You Go

We know that you'll love our service!

Schedule an inspection with All Dry USA today.


Schedule Inspection