Garbage Disposal Won’t Drain? Try These DIY Fixes

Dealing with a garbage disposal that hums but won’t drain can be frustrating, especially when you cannot pinpoint the cause of the blockage.

Drawing from insights shared by DIY enthusiasts on forums and Reddit, it’s clear that this issue can arise from various root causes. 

The good news is that there are multiple solutions to experiment with. Let’s break them down.

Table of Contents

• Garbage Disposal Won’t Drain: Causes and Solutions
  • 1. Check for Jams and Blockages
  • 2. Inspect the P-Trap For Blockage
  • 3. Check the Outlet of the Disposal
  • 4. Create Water Pressure to Push Out the Clog
  • 5. Consider a Plunger
  • 6. Be Mindful of What You Put in the Disposal
  • 7. Flush with Hot Water or Drain Cleaner
  • 8. Call a Plumber If All Else Fails
• Conclusion

Garbage Disposal Won’t Drain: Causes and Solutions

This chapter will guide you through various scenarios to help you identify the main cause of the garbage disposal drainage problem. 

1. Check for Jams and Blockages

One of the most common causes of a garbage disposal that won’t drain is a blockage inside the disposal or pipes. Even if you think there’s nothing in there, it’s worth double-checking. Here’s how to go about it:

• Reset the Disposal: Start by pressing the reset button located at the bottom of the unit. If the disposal is humming but not spinning, the reset might help.

• Manually Rotate the Flywheel: If you hear that humming noise but the disposal isn’t working, it likely means something is stuck. Many disposals have an Allen wrench slot at the bottom (also known as an unjam socket). Insert the wrench and try to manually turn the flywheel. This could free up whatever is causing the jam.

If your garbage disposal unit does not have a hex-shaped hole at the bottom, you can use a broom handle to manually rotate the flywheel. 

Grab your broom, flip it down, and place it between the impellers. Now, use force to rotate the impellers or the flywheel. This will help break free the blockage. 

2. Inspect the P-Trap For Blockage

If your disposal is running but the water won’t drain, there’s likely a clog somewhere between the disposal and the pipes. Here’s a method that many forum users swear by:

• Turn Off the Power: Always ensure that the power to the garbage disposal is off before working on it.

• Disassemble the Pipes: Disconnect the pipes, including the P-trap (the U-shaped pipe under the sink), and check for any obstructions. Food debris, grease, and other gunk can build up in the pipes, causing slow drainage.

As one user noted, if you’ve removed the P-trap and don’t see anything obvious, there’s a chance the clog could be further down the line in the pipe that leads into the wall. At this point, using a drain snake might be necessary to break up any clogs beyond what you can reach.

3. Check the Outlet of the Disposal

Sometimes, the clog could be inside the disposal’s lower chamber or downspout. As one forum user described, grease, fibrous food (like watermelon rinds), or mashed potatoes can form a paste that clogs up the outlet of the disposal.

• Unplug the Disposal: Safety first! Once it’s off, disconnect the drain pipe connected to the disposal.

• Inspect the Outlet: Look inside the disposal’s outlet to see if any food waste or grease buildup is clogging the system.

• Clean Out the Clog: Use a probe, brush, or any similar tool to remove the buildup. After that, reassemble the pipes and flush the system with hot water for several minutes to make sure everything is cleared out.

4. Create Water Pressure to Push Out the Clog

If the clog seems to be deeper in the pipes, you can try this trick to force it through:

• Fill the Disposal Sink with Water: Plug the sink and fill it with water. Once it’s full, plug the other sink (if you have a double sink).

• Turn on the Disposal: When you turn it on, the curved blades of the disposal can act like a pump, pushing the water through the clog and hopefully clearing the obstruction.

Several users have found that a mix of hot water and the natural pumping action of the disposal helps dislodge stubborn blockages.

5. Consider a Plunger

You wouldn’t think of using a plunger in a kitchen sink, but it’s another method worth trying.

• Use a Plunger: Place a sink plunger over the disposal side and plunge away. The suction can help loosen any blockages that might be stuck further down the drain.

6. Be Mindful of What You Put in the Disposal

Many users reported that putting fibrous or starchy foods, such as potato peels, banana peels, or watermelon rinds, can cause clogs. These items tend to form clumps or get caught in the grinder, which can then block the drain. 

To avoid future problems, it’s best to scrape large food particles into the trash instead of the disposal.

Always run plenty of water when using the disposal to help flush food particles all the way down the drain, preventing them from sticking to the inside of the pipes.

7. Flush with Hot Water or Drain Cleaner

If you’ve tried all the physical methods and the water still isn’t draining, some users recommend flushing the system with hot water or using a drain cleaner like Drano.

• Fill with Hot Water: Hot water helps break down grease and debris stuck in the pipes. You can fill both sinks with hot water and let it sit, allowing the weight of the water to help push the clog through.

However, be careful with chemical cleaners, as they can damage pipes over time if used too often.

8. Call a Plumber If All Else Fails

If you’ve tried resetting the disposal, manually freeing the flywheel, clearing the P-trap, and using a snake with no success, it may be time to call in a professional plumber. 

Sometimes, the clog could be located further down the drain line where homeowner tools can’t reach. 

A plumber can use advanced equipment, like a longer drain snake or even a hydro-jet, to clear the blockage.

Conclusion

A garbage disposal that won’t drain can be due to anything from a minor jam to a significant clog further down the pipes. 

The most important steps are to turn off the power, check for any blockages, and work your way down from the disposal chamber to the pipes. 

With some patience and the right tools, you should be able to resolve the issue. But if it proves to be more complicated, don’t hesitate to bring in a plumber.

With these tips in mind, you should be ready to tackle your disposal problems with confidence!

You can also download our garbage disposal manual. With easy, actionable advice, this manual empowers you to solve problems confidently—whether it’s a minor fix or a more complex repair.

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