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How to Diagnose and Repair a Clogged Sink: A Step-by-Step DIY Guide

7/28/2025
An image of a clogged kitchen sink.

A clogged sink can turn your home into a plumbing headache. Whether it’s a slow drain or a full-on backup, this guide will help you tackle the issue with confidence and clarity. Let’s dive in!

Step 1: Diagnose the Problem

Before grabbing tools, identify where the clog is and what might be causing it.

  • Check for slow drainage: If water pools and drains slowly, it’s likely a partial clog.
  • Listen for gurgling sounds: This can indicate a blockage deeper in the drain line.
  • Inspect both basins (if double sink): If both are affected, the clog is likely in the shared drain line.

Clogged Kitchen Sink Diagnosis and Fix walks through inspecting the U-trap and even checking pipes in the basement for deeper clogs.

Step 2: Try Simple Solutions First

Start with the least invasive methods:

  1. Boiling water: Pour it down the drain to dissolve grease or soap buildup.
  2. Plunger: Create a seal and plunge vigorously.
  3. Baking soda + vinegar: Let it fizz for 15 minutes, then flush with hot water.

Step 3: Remove and Inspect the P-Trap

If plunging doesn’t work, it’s time to go under the sink.

  1. Place a bucket underneath to catch water.
  2. Unscrew the P-trap (the curved pipe under the sink).
  3. Check for debris like food, grease, or hair.
  4. Clean thoroughly and reattach.

How to Unclog a Sink — The Right Way gives a clear walkthrough of removing, inspecting, and cleaning the P-trap and other components.

Step 4: Use a Drain Snake or Zip-It Tool

If the clog isn’t in the trap:

  1. Insert a drain snake into the pipe leading into the wall.
  2. Rotate and push gently to break up the clog.
  3. Pull out debris and flush with hot water.

How to Unclog Any Drain | Ask This Old House demonstrates how to use a drain auger and wire to clear stubborn clogs in various household drains

Step 5: Reassemble and Test

Once the clog is cleared:

  1. Reattach all pipes securely.
  2. Run hot water to flush the system.
  3. Check for leaks at all connections.

How to Clear a Clogged Sink Drain | This Old House shows how to test connections and ensure everything is sealed properly.

Bonus: Bathroom Sink Tips

Bathroom sinks often clog due to hair and soap scum.

  • Remove the pop-up stopper and clean it.
  • Check overflow holes for blockages.

How to Fix a Slow Draining or Clogged Bathroom Sink offers a focused guide on bathroom-specific clogs.

Final Thoughts

With a little patience and the right tools, you can restore your sink’s flow and avoid costly plumber visits. A DIY project like this can save you money and is well worth a try and of course you can get help from Edwards Enterprises if you find the job to be bigger than expected. We are always here to help in Santa Barbara, Ventura and West LA County with any plumbing issues you have.