“Leak Under Kitchen Sink When Water is Turned On: Discover the Hidden Culprit and Easy DIY Fixes!”

By bobbreich@gmail.com •  Updated: 11/21/23 •  5 min read

Leak Under Kitchen Sink When Water is Turned On: Discover the Hidden Culprit and Easy DIY Fixes!


Have you ever experienced a leak under your kitchen sink when you turn on the water? It can be frustrating and even damaging to your home if left unattended. In this blog post, we will explore the common causes of a leak under the kitchen sink when water is turned on and provide you with easy DIY solutions to fix the issue. Addressing this problem immediately is crucial to prevent further damage to your kitchen and keep your home safe.

Understanding the Causes of a Leak Under Kitchen Sink

There are several common reasons why leaks occur under the kitchen sink when water is turned on. Some of these include:

1. Loose or worn-out connections: Over time, the connections between pipes can become loose or worn out, leading to leaks.

2. Faulty faucet: A leaky faucet can also cause water to drip down into the cabinet under the sink.

3. Damaged pipes: Pipes can get damaged due to corrosion, freezing, or physical impact, resulting in leaks.

Identifying potential sources of the leak requires careful inspection of various components under your kitchen sink.

Finding the Hidden Culprit: Step-by-Step Inspection Guide

Before jumping into repairs, it’s essential to prepare for inspection properly. Here’s how you can do it:

1. Gather necessary tools and materials such as a flashlight, adjustable wrench, pipe wrench, plumber’s tape, and bucket for collecting water.

2. Clear out any items stored under your sink to have better access during inspection.

Once prepared, follow these steps for a thorough inspection:

1. Check all connections: Inspect each connection point for signs of leakage or moisture buildup. Tighten any loose connections using an adjustable wrench if needed.

2. Examine faucet components: Look for visible signs of wear or damage on faucet handles and spouts that could be causing leaks. Replace any faulty components as necessary.

3. Inspect the sink drain: Check the seal and gasket around the sink drain for any cracks or damage. Replace the seal if necessary.

Fixing a Leaky Faucet: DIY Solutions

A common cause of leaks under the kitchen sink when water is turned on is a faulty faucet. Here are some possible causes and solutions for faucet leaks:

1. Worn-out O-rings or washers: These small rubber components can deteriorate over time, causing leaks. Replace them with new ones to fix the issue.

2. Loose connections: If you notice water dripping from around the handle or spout, tightening the connections using an adjustable wrench may solve the problem.

Follow these step-by-step instructions to repair a leaky faucet under your sink:

1. Turn off the water supply to your kitchen sink before starting any repairs.

2. Remove any decorative caps, handles, or trim from your faucet to access the internal components.

3. Take out and replace worn-out O-rings or washers using pliers or a screwdriver, depending on your faucet design.

4. Reassemble all components in reverse order and turn on the water supply to test for leaks.

Repairing Leaking Sink Pipes: Easy DIY Tips

Another common culprit behind a leak under your kitchen sink when water is turned on is damaged pipes. Here’s how you can identify pipe issues leading to leaks:

1. Inspect all visible pipes under your sink for signs of corrosion, cracks, or loose joints that may be causing leaks.

2. Look for moisture buildup or water stains around pipes as it indicates an active leak.

Minor pipe leaks can often be fixed without professional help using simple techniques such as:

1. Applying plumber’s tape: If you notice small drips coming from threaded pipe fittings, wrapping plumber’s tape tightly around them can stop the leaks temporarily until more permanent repairs can be made.

2. Using pipe epoxy: For small cracks or holes in pipes, applying a layer of pipe epoxy can create a seal and prevent further leakage.

Addressing Drainage Problems: DIY Fixes

Sometimes, sink leaks can be caused by drainage issues. Here are some potential causes and step-by-step instructions on how to unclog or repair sink drains:

1. Clogged drain pipe: Hair, food particles, and grease can accumulate in the drainpipe over time, causing blockages. Use a plumber’s snake or drain auger to remove the clog.

2. Faulty P-trap: The P-trap is a U-shaped pipe under the sink that traps debris and prevents odors from coming back up through the drain. Check for any clogs or damage in the P-trap and clean or replace it accordingly.

Essential Tools and Materials needed for Repairs

To effectively address the leak under your kitchen sink when water is turned on, you’ll need these essential tools:

1. Flashlight
2. Adjustable wrench
3. Pipe wrench
4. Plumber’s tape
5. Bucket for collecting water

In addition to these tools, here are some suggested materials required for effective repairs:

1. O-rings or washers
2. Plumber’s tape
3. Pipe epoxy
4. Plumber’s snake or drain auger

Taking Preventive Measures against Future Leaks

Once you’ve successfully fixed the leak under your kitchen sink when water is turned on, it’s essential to take preventive measures to avoid future issues:

1. Regularly inspect connections and components under your sink for signs of wear or damage.
2.Utilize maintenance suggestions such as using mesh screens to catch debris before they enter pipes.
3.Schedule periodic inspections by a professional plumber to ensure everything is working properly.

By following these preventive measures and implementing a maintenance routine, you can significantly reduce the chances of experiencing future leaks.


A leak under the kitchen sink when water is turned on can be a frustrating problem, but with proper inspection and DIY fixes, it can be resolved easily. Identifying the hidden culprit, whether it’s a faulty faucet, damaged pipes, or drainage issues, is the first step. Armed with the right tools and materials, you can repair the issue and take preventive measures to avoid future leaks. Remember to address this problem immediately to prevent further damage and keep your kitchen safe.