Top 5 Common Causes of Kitchen Sink Leaks

Kitchen sinks are among the most heavily used items in our homes. Daily, we wash dishes, prepare meals, pour water, and much more. Wear and tear from frequent use is normal, and leaks will happen. In this article, I have researched the top 5 common causes of kitchen sink leaks and how to fix them.

From a faulty water supply connection to damaged O-rings, there are various reasons for kitchen sink links. Here are the top common causes.

1. Faulty Drain

Regardless of the type of sink you have, a faulty drain is a common cause of the kitchen sink leaking. Reasons can vary, but the most likely ones are worn out or incorrectly applied plumber’s putty.

Even if the plumber’s putty was applied correctly, it will dry out and crack over time. The older your sink is, the more likely it is to have problems.

But it also depends on how you use the sink. If you routinely pour boiling water or other liquids, your sink will experience expansions and contractions between the sink and the strainer.

Expansions, contractions, and usage will deteriorate the plumber’s putty and make the strainer lose.

If your drain is old, you may be better off replacing it.

How to Troubleshoot a Drain Leak

To locate the leak, wipe away any water that remained from earlier leaks.

Fill your sink with water after you plug it with the drain cover. Then unplug the sink and look underneath to see where the leak is coming from (you may need a flashlight for this.)

If the strainer is not too old, you may fix the leak by tightening pipe connections or applying new putty.

If your strainer had better days, you should replace it with a new one. It is not that hard to do it yourself. The video below shows how to do it.

How to Replace a Kitchen Sink Strainer

Plumbing expert Richard Trethewey from This Old House helps a homeowner replace a rusty sink strainer in the kitchen.

2. Faulty Faucet

Another common cause of a leaking sink is a faulty faucet. Luckily, this problem is easy to see. You will frequently notice water at the faucet base or even see it dripping. Some issues with faucets may even cause leaks under the sink.

Old cartridges and loose nuts are a common reason for leaky faucets, and you can easily fix them yourself. If the problem remains, you should think about replacing the entire faucet, which is also reasonably easy to do.

How to Fix a Leaky Faucet

This is an excellent video from the Home Depot on how to fix a leaky faucet. Short and to the point.

One thing missing from the video is to make sure you take your old cartridge to the store to make sure you purchase the right one out of the many stiles available.

3. Poor Water Supply Connection

For a faucet to deliver water, it must be connected to a water supply source. If the connection has a problem, you may notice leaks under your sink, which will be constant, even when you do not use the sink.

The main problem with these is that they are sort of hidden, and it is hard to notice it before the water starts flooding the cabinet.

Loose connections or faulty shut-off valves and supply lines are usually the main culprits for this type of leak. Replacing the shut off valve and/or the supply line is the typical solution to the problem.

How to Fix a Sink Leak From a Supply Connection

Below is a helpful and detailed 10-minute video where you will learn how to replace the shut-off valve and supply line.

The shut-off valve and supply line turned out not to be the cause of the leak, so the homeowner ended up replacing the faucet to solve the issue.

This video is for a bathroom sink, but the principles are the same for a kitchen sink.

4. P-Trap Blockage 

P-trap is that curved part of the pipe underneath your sink. The P-trap is there to prevent sewer gases from getting into your home. It holds a small amount of water, which blocks gases from rising up into your home.

Same as the water supply connection, it is hidden, and most of the time, you won’t look underneath your sink. It can cause your cabinet to flood if you don’t notice it in time.

Because kitchen sinks are so heavily used, small particles of food and dirt will accumulate within a P-trap, and with time these items can obstruct proper drainage. In addition to poor drainage, a blockage can cause leaks. The best solution for this is to clean or replace the P-trap.

How to Unclog a Kitchen Sink

This video from Roger Wakefield goes over the various potential culprits of kitchen sink clogs and how to fix them.

5. Faulty O-Ring

O-ring is a circular band typically made out of rubber that is located at the base of your faucet. With time, this ring can get damaged or move out of its original place. When that happens, the water will find a way out and start leaking.

This problem is quite easy to notice, and you can fix it by replacing the faulty part.

Leaky Faucet Base – O-Ring Replacement

If you notice water leaking around the base of your kitchen faucet, chances are it is due to a worn-out O-ring seal. As this video demonstrates, this is an easy DIY project.

Related Posts:

Leave a Comment