Informational Guide

Sink Only Drains When Garbage Disposal Is On

Are you stuck with a kitchen sink that only drains when the garbage disposal is on? We take a look at the main causes and easiest fixes.

by Ian Haynes

Does your kitchen sink only drain when a garbage disposal is on? If so, you’re not alone. Many households in the US are even stuck with sinks that don’t drain at all!  

Clogged sinks can be disgusting and pretty annoying. But it’s nothing you can’t fix with a little bit of effort!  

This helpful guide will help you handle and diagnose garbage disposal troubles and ways to prevent them. Read on! 

Wondering why your sink only drains when the garbage disposal is on? That’s because when the disposal is functioning, the spinning disc or impeller plate rotates rapidly, shredding food into a drainable size.  

If your sink still can’t drain without the disposal, it’s either clogged or jammed. Here are some reasons why your kitchen sinks only drain when a garbage disposal is on: 

1. Broken Garbage Disposal 

garbage disposal unit is one of those fixtures that can sound wonky even when it’s okay. However, if you hear it running normally but not grinding, you have a broken garbage disposal.  

Typically, in many cases, you can effortlessly troubleshoot the problem by simply replacing it or restarting it.    

2. Clogged Garbage Disposal 

If you see water standing in the kitchen sink, you have a clogged drain. This could either be because of the drain line or the garbage disposal.  

Clogging can occur due to many factors, but the culprit is usually hard food remains. You can unclog garbage disposal by dismantling the drain pipe beneath the sink. 

white modern kitchen sink

3. Jammed Garbage Disposal 

Another symptom of inadequate drain functionality is if the sink is draining water, but slowly. 

This is just a precursor to having a clogged drain because the reason is the same: food particles – getting stuck in the impeller, causing slow drainage.  

And if the disposal is jammed genuinely, you won’t unclog the unit using conventional plumbing methods.    

4. Full Garbage Disposal 

If you have tossed a considerable amount of food into the garbage disposal, it will have to be chopped into pieces before the sink starts draining.  

A full disposal will never operate appropriately because it doesn’t provide room for the blades to move, leading to slow or no draining. This is why it’s important to know what you can and can’t put in the garbage disposal.  

How To Fix Draining Problems With A Garbage Disposal 

1. How To Fix A Broken Garbage Disposal 

Follow the steps below to fix the broken garbage disposal: 

  • 1
    Examine the breaker panel 
  • 2
    Ensure that each breaker is working and hasn’t been tripped 
  • 3
    Flip the button saying “kitchen” or “garbage disposal”  
  • 4
    Test the unit again 
  • 5
    Unplug the disposal and use a hex key to unjam the blades 
  • 6
    Push the reset button  

2. How To Fix A Clogged Garbage Disposal 

Here’s your step-by-step guide to removing softer items causing clogs in your garbage disposal. These steps should ensure that your sink works normally:  

  • 1
    Please make sure the garbage disposal is unplugged and keep it disconnected until you finish fixing it 
  • 2
    Use your sink/toilet plunger to unclog the drain 
  • 3
    Rinse the drain thoroughly with water to ensure the remaining clog is also removed.  
  • 4
    Plug the garbage disposal back in 
  • 5
    Pour an industrial sink/disposal cleaner into the unit  
Water coming out of farmhouse sink

3. How To Fix A Jammed Garbage Disposal 

What if the garbage disposal isn’t clogged, and you’re still having problems with draining? This happens when harder items such as glass get stuck in the impeller, causing a slow drain.

Here’s a step by step guide to fixing jammed garbage disposal: 

  • 1
    First, unplug your garbage disposal as a safety measure 
  • 2
    Put a bucket beneath the drain trap. It’s where all sludge runs when using the garbage disposal  
  • 3
    With the help of channel lock pliers, unclasp the slip nut fillings on the drain trap. This ensures that the waste and water flow into your bucket 
  • 4
    In case you notice a stuck piece of debris, carefully remove it 
  • 5
    Now, wash the drain trap with a pipe cleaner or scrub brush  
  • 6
    Afterward, examine the drain arm and scoop out all the waste you notice.  
  • 7
    Tip: You can remove the drain arm by unclasping the slip-nuts. If you want to remove extra clogs and jams, take a scrub brush and clean the arm 
  • 8
    Reset the garbage disposal  
  • 9
    For better results, make sure to add a few enzyme-based cleaners to your drain and flush it with water  

4. How To Empty A Full Garbage Disposal 

Emptying a full garbage disposal is relatively easy. Here’s how to do it: 

  • 1
    First, remove all sorts of blockages. Turn off the disposal and take out all fragments using pliers or cooking tongs.
  • 2
    Clean the blades or grinders. Pour some ice into your garbage disposal and run ice-cold water for 15 seconds.
  • 3
    Now, empty drainage pipe. Use water to rinse any leftover debris from the garbage disposal. 

When To Call A Professional Plumber 

Call a professional plumber in either of these cases: 

  • If none of the above-mentioned solutions work 
  • If you don’t have the required knowledge, experience, or tools to do it yourself 
  • If you’ve got backups with the sink, toilet, or tub, the problem isn’t with the garbage disposal. Instead, there may be a clog in your primary plumbing 
  • If you are using a septic tank, it may require emptying 

Nevertheless, the average cost to hire a professional plumber to fix a garbage disposal ranges from $40 to $250 per hour. Unfortunately, some may even charge up to $410 for minor work. For a free quote in your area, fill in the form below!

Preventing Garbage Disposals Drainage Issues: Dos & Don’ts 

Disposals can turn out to be a tricky puzzle. So to ensure your garbage disposal unit operates safely and smoothly, follow these Dos and Don’ts 


  • Only utilize ice-cold water when you’re running the disposal 
  • Slowly place items – hard or soft – down the sink drain  
  • To avoid buildup, run your garbage disposal routinely to remove any stuck food pieces  
  • Grind ice in your disposal to wash the insides 
  • When not in use, cover the drain with a lid to avoid items plunging into the garbage disposal. 
  • Employ citrus rinds/peels to freshen your unit. Also, you can use baking soda to remove odors of any kind. 
  • In case it jams, turn it off immediately 


  • Switch it on without water  
  • Allow waste/sludge to sit within the garbage disposal  
  • Insert some grease into the drain 
  • Grind fibrous items (i.e., carrots, artichokes, and asparagus) 
  • Put potatoes, pasta, or rice into the drain 
  • Incinerate anything hard or sharp such as seeds, coffee grounds, and large bones 
  • Reach with hands to eliminate jams or clogs 
  • Pour dense drain chemicals or cleaners into the garbage disposal  

People also Ask (FAQs)

Can garbage disposals cause major plumbing problems? 

If the garbage disposal isn’t maintained or operated correctly, chances are it may break down, clog or jam your drains. This will cause further plumbing nightmares. A clogged drain is a serious inconvenience, and professional disposal fixing can cost you a pretty penny.   

How long should you run a garbage disposal? 

Run your garbage disposal until all food items are gone — typically, 30 to 40 seconds are enough. Then, switch the unit off and ensure the water runs for another 11 to 16-second to flush the drain. Also, even if there is no food item to grind, switch it on and run it for few seconds every day to keep it in good working condition. 

How do you manually drain a garbage disposal? 

Here’s how you can drain garbage disposal manually: 

  • Turn the unit off 
  • Insert either a broom handle, wooden spoon, or a dowel 
  • Warning: make sure you don’t insert your hand in any case 
  • Push the end of your wooden spoon against the unit’s impeller  
  • When you feel the impeller moving freely, turn the power on after waiting for at least 13 minutes and press the “reset” button 
Can coke unclog a drain? 

Yes, you can unclog a drain using a coke. Pour 2 liters of Coke, Pepsi, or another cola inside the jammed or clogged drain. They’re pretty effective at washing away any buildup in the drain; however, compared to commercial cleaners, Coke is milder.  


Garbage disposal is an integral part of any kitchen, provided the unit is working correctly. If you face a situation where the kitchens sink only drains when a garbage disposal is on, don’t panic! Instead, follow our step-by-step solutions or call a professional!  

Ian Haynes is an expert writer who has successfully deployed over 500 plumbing pages and other related content. He has an excellent understanding of home plumbing issues and translates his experiences via Plumbing Lab so readers can have a better understanding of common household problems. Outside of his work, Ian likes exploring Brooklyn with his Labrador.