11 March A woman calling a plumber while attempting to fix a leak under the kitchen sink

How to Fix a Leak Under Your Kitchen Sink

Posted by PlumbWize

A kitchen sink leaking in your home is a surefire way to waste water and drive up your utility bill. The longer you leave it, the worse it’ll get!

Calling a plumber is a smart idea, but while you wait for them to arrive you can also try a few things to minimize the damage or at least contain it. We’re going to walk you through them in this blog to help you limit water damage and get your sink working as intended again.

Ready? Here’s what to do if you have a sink leaking!

Common Causes of Leaks and Solutions

There are many common causes of a leaky sink, and the trick to fixing them is to figure out where the leak is coming from. To start, check these parts of your kitchen sink:


A faucet is often to blame for a kitchen sink leaking. You’ll know it’s causing the leak if water pools on top of the sink and comes from parts other than the spout.

🔨 Quick Fix: Disassemble the faucet handle and replace the cartridge, seat and springs:

  • Remove the faucet handle with an Allen wrench.
  • Remove the retainer nut, cartridge, seats and springs.
  • Replace the cartridge, seats and springs with new ones.

 A plumber fixing a single-handle kitchen faucet

Image source: Shutterstock

Drain Pipe

If there’s a leak under your kitchen sink when the water is turned on, your drain pipe might be the problem. It could be because of a loose nut or gasket.

🔨 Quick Fix: To stop drain leaks under your kitchen sink, tighten the pipe slip nuts by hand. Run the water and see if the water still leaks.

Water Supply Valve

Water supply leaks can cause major water damage in homes if not addressed quickly.

Not only will this issue create a huge mess in your kitchen, but the costs of repairs may also run your bank account dry. To confirm if yours is causing your kitchen sink leak, plug your sink drain, turn on your faucet, and then let the water run for a few seconds.

If the kitchen sink leaking continues when the water is turned on and the drain is clogged, your water supply is the culprit.

🔨 Quick Fix: Tighten the water supply valve and see if that stops the leak.

If this does not improve the situation, some parts might need to be replaced. That said, if your water supply lines are five years old or older, then you may need to consult a professional to replace these pipes instead of repairing them.

Hot and Cold Supply Lines

Hot and cold supply lines can also cause a kitchen sink leak.

If you find water pooling under your sink with the water running or drips coming from the water supply lines, these may be to blame.

🔨 Quick Fix: Tighten the nuts that connect them to their cutoff valves.

Sink Strainer

This is the problem if the sink strainer drips underneath when you run water on the sink, and there are droplets of water when it’s not draining.

🔨 Quick Fix: This could be due to cracked putty on the sink drain. To fix it, disassemble the pipe and remove the kitchen sink drain assembly. You should then:

  1. Remove the remaining putty on the sink drain’s rim.
  2. Apply plumber’s putty on the sink drain and place it back into the drain hole.
  3. Lock the basket strainer with a nut underneath the sink.

A plumber locking the drain pipe nut underneath a kitchen sink

Image source: Canva

When to Call a Professional

While it’s always good to learn how to fix a leaking kitchen sink, most of the time, the best solution is to call a plumber to repair the issue.

Your home’s plumbing system can be complicated, and poking around too much, especially when you don’t have extensive experience in plumbing, could result in further damage. Moreover, some leaks may not be accessible without professional tools and guidance.

Kitchen Sink Leaking? Call PlumbWize!

If you’ve exhausted all possible means to fix the leak under your kitchen sink and the problem still persists, it may be because DIY solutions aren’t enough. Save yourself the time and effort and call the experts at PlumbWize for assistance!

We’ve been in the plumbing business for more than 60 years; you can trust we know our way around faucets, drain pipes, sink basins, and water supply line issues. We provide 24/7 repairs for other types of plumbing system problems as well.

So, if you have a leaky kitchen sink, contact us for a permanent solution!


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