Garbage Disposal Drains Slowly? Causes and Easy Solutions

Q. I recently remodeled my kitchen and installed a garbage disposal under the sink. After a few days, I experienced a problem with the sink. The sink drains slowly. What is the reason behind this issue? 

My Opinion: The sink or garbage disposal drains slowly due to a clogged P-trap. The P-trap or tee-fitting connects the garbage disposal to the waste line. 

Generally, the P-trap or tee-fitting gets restricted if you flush rice, pasta, or fibrous foods. Rice and Pasta expand when mixed with water. As a result, they clog the P-trap, which causes the garbage disposal to drain slowly. 

Removing the restriction from the P-trap will resolve the garbage disposal drainage issue. To do so, you need to disconnect the P-trap and may need to snake the branch drain. 

Below, I will show you how to disconnect the P-trap that connects the garbage disposal & the waste line and how to unclog the P-trap. 

Table of Contents

• Clean the P-trap or Drain Trap to Fix Slow Draining Garbage Disposal
• What Are The Other Reasons Responsible for A Slow-Draining Garbage Disposal? 
  • Clogs in The Disposal
  • Air Gap Issues
  • Improper Use of Garbage Disposal 
• FAQs
• Need Help In Repairing Your Garbage Disposal? Chat With FixTheDisposal

Clean the P-trap or Drain Trap to Fix Slow Draining Garbage Disposal

To clean the drain trap, follow these step-by-step instructions:

• Go underneath the sink and use channel-type pliers to unscrew the nuts on the drain trap. Don’t forget to place a plastic bucket under the P-trap as it may fill with water and nasty food waste.

• Remove the P-trap or the drain trap from the pipe connection.

• Clean the drain trap. Use a wire or a scrubbing brush to dig out the food debris from the hard-to-reach areas of the P-trap. Then, flush the P-trap under running water to clean it thoroughly.

• Inspect the other branch drain lines for a restriction. If required, snake out the other piping to release blockage.

• Reconnect the drain trap to the disposal discharge line. Connect the P-trap with the disposal’s discharge line and the waste line that goes into the wall. Secure the drain trap with the provided nuts.

• Turn on the cold water supply to flush out any remaining debris from the disposal and the drain line.

Alternatively, you can plunge your garbage disposal to fix the slow-draining garbage disposal.

In this case, get a plunger and set it at the sink opening. Then, keep plunging, creating a force to release the restriction from the drain line.

The plunging method works like a charm, especially if you have a double sink with garbage disposal. Watch this video to learn how to use the plunger to fix the slow-draining issue: 

What Are The Other Reasons Responsible for A Slow-Draining Garbage Disposal?

Apart from a clogged P-trap, your garbage disposal drains slowly due to clogs, air gap issues, and improper use of the disposal unit. 

Clogs in The Disposal

Over time, food waste can accumulate in the disposal or pipes, leading to slow drainage. The disposal gets clogged due to putting unprohibited food waste like rice, pasta, coffee grounds, and non-food items. 

Read: What Not To Put In Garbage Disposal?

How To Fix:

You can fix the minor clogs by flushing out the garbage disposal. 

Regarding this, put the stopper in the sink opening and fill the sink with water. Mix vinegar and baking soda with water. 

Then, pull out the stopper, which will help flush out the accumulated food buildup from the disposal unit. 

On the other hand, if the disposal gets jammed, you need to rotate the impellers manually to unjam the disposal unit. 

Air Gap Issues

If you connect your dishwasher to the garbage disposal without proper air gaps, your disposal or disposer can go through the drainage issue. 

Connecting the dishwasher hose to the disposal without removing the disposal knock-out plug is a common cause of air gap issues.

Besides, a clogged air gap is another culprit that can throw a wrench into work and cause the disposal to drain slowly. 

How To Fix: 

First, disconnect the dishwasher hose from the disposal inlet. Then, insert your fingers into the disposal inlet to verify that you remove the knock-out plug. If not, hammer down the knock-out plug. 

Then, fish out the knock-out plug from your garbage disposal. Lastly, reconnect the dishwasher hose to the disposal. 

To fix the air gap issues due to dirty air gap, you can watch this tutorial: 

Improper Use of Garbage Disposal

Improper use, for example, running insufficient water and disposing of unprohibited food waste like coffee grounds, rice, and pasta in the disposal can cause drainage issues. 

How To Fix: 

Maintain best practices when using the garbage disposal. For example, run plenty of water when operating the garbage disposal. Turn on the cold water before, during, and after using the food waste disposal. 

Don’t put food waste like rice, pasta, celery, corn husks, fruit pits, grease, coffee grounds, and non-food items in the garbage disposal. 

You can read this article to learn how to use garbage disposal properly & safely. 

FAQs

What are the most common items that cause clogs in garbage disposal?

Several items that can lead to clogs in the garbage disposal are FOG (fat, oil, and grease), coffee grounds, fibrous foods (celery, cornhusks, asparagus), starchy foods (rice, pasta, potato peels), eggshells, fruit pits, bones, and non-food items (plastics, glasses, forks, and spoons). 

Are there any specific tools that are essential for unclogging a slow-draining disposal?

Here is the list of essential tools for unclogging a slow-draining disposal:

• Channel-type pliers: Help you loosen the nuts on the disposal drain trap.

• Plastic Bucket: To catch water and nasty food waste when disconnecting the P-trap.

• Tongs: Use to reach into the grinding chamber to grab items stuck in the disposal.

• Allen Wrench: This tool helps you rotate the impellers manually if they get jammed.

• Flashlight: Help you identify restrictions in the grinding chamber.

• Baking Soda & Vinegar: These household items help break down clogs.

How do I know if my P-trap is clogged and needs cleaning?

To determine if your P-trap is clogged and needs cleaning, look for these signs:

• Slow Drainage: If your garbage disposal drains more slowly than usual, I bet the P-trap gets partially clogged.

• Water Backups: If water is backing up into the sink, it indicates there may be a blockage in the drain line, particularly in the P-trap.

• Gurgling Noises: You will hear a gurgling noise when the disposal drains, which indicates a possible clog in the P-trap. 

Need Help In Repairing Your Garbage Disposal? Chat With FixTheDisposal

A clogged P-trap is the main culprit behind a slow draining garbage disposal. 

The solution to this issue is simple. 

Clean the P-trap. Just disconnect the P-trap from the disposal discharge line and the pipe that goes into the wall. Then, use a scrubbing brush to dig out the debris or gunk accumulated in the P-trap. 

Rinse the drain trap thoroughly under running water. Finally, reconnect the P-trap and flush out the garbage disposal. 

Do you need a helping hand to repair your garbage disposal? FixTheDisposal is here to give their shoulder. Just explain your problems you are experiencing with your garbage disposal and our expert plumbers will chat with you to resolve your issues.

Call us or visit the Contact Us page.