Fix: Garbage Disposal Humming but Not Working

A humming garbage disposal that won’t turn on can be a frustrating problem in the kitchen. However, there are several common reasons why your disposal may be humming instead of operating normally, and many issues can be fixed with some simple troubleshooting and DIY repairs. Here’s how to diagnose and fix a humming garbage disposal.

What Causes a Humming Garbage Disposal?

When you flip the switch and your garbage disposal hums but doesn’t grind up food waste, it means the motor is running, but the blades are jammed. Here are some of the most common causes of humming garbage disposal:

  • Jammed impellers or flywheels– Food waste or foreign objects like silverware can get lodged between the impeller blades and prevent them from turning. This causes the motor to hum as it tries unsuccessfully to spin.
  • Faulty or worn-out motor– If the motor is malfunctioning, it may hum but not have enough power to turn the blades. Older disposals may have motors that burn out over time.
  • The reset button is tripped– Many disposals have a reset button that trips and cuts power to the unit when it overheats or jams. This will make your disposal hum when you try to turn it on.
  • Electrical issues– Problems with the power supply, faulty wiring, or a tripped circuit breaker can prevent the motor from starting properly.

Step-by-Step Guide to Fix a Humming Garbage Disposal

Follow these steps to troubleshoot and fix humming garbage disposal:

1. Unplug the Garbage Disposal

Before attempting any repairs, unplug the garbage disposal from the electrical outlet. This prevents injury if the unit accidentally turns on.

2. Check for Blockages

Inspect the inside of the disposal chamber and drain opening. Look for food waste, foreign objects, grease buildup, etc., that could be preventing the blades from turning. Use tongs or pliers to remove any debris.

3. Test the Reset Button

Many disposals have a red reset button on the bottom. Press this button and see if the disposal now works normally. This may indicate the unit overheated and tripped the reset.

4. Manually Turn the Flywheel

Insert an Allen wrench into the bottom of the disposal and rotate it back and forth. This should manually spin the flywheel and may dislodge any stuck debris.

5. Inspect the Motor

If the blades spin freely but the disposal still hums, the motor may be worn out or faulty. Have an appliance repair technician inspect the motor and advise whether it needs repair or replacement.

6. Check Electrical Connections

Verify that the disposal is getting power by plugging something else into the outlet. Check for any loose wiring connections. Reset circuit breakers that may have tripped.

7. Clear Clogged Drains

A clogged drain line can prevent proper drainage and cause the disposal to hum. Use a plunger, drain snake, or drain cleaner to clear clogs.

8. Replace Faulty Parts

If specific components like the flywheel or grind ring are damaged, replacement parts may be needed. Only use OEM parts to ensure proper fit and function.

How to Prevent Future Problems

Follow these tips to keep your garbage disposal working properly:

  • Run plenty of cold water when operating the disposal to flush waste through
  • Avoid putting fibrous or starchy foods down the drain
  • Grind ice cubes periodically to clean the blades
  • Don’t put coffee grounds, grease, or non-food items into the disposal
  • Regularly clean the disposal with baking soda and vinegar
  • Have the unit inspected annually to identify any worn parts

When to Call a Professional

If you are unable to diagnose the specific cause of the humming or DIY repairs do not solve the problem, it’s time to call a professional plumber or appliance repair technician. They can inspect the garbage disposal and determine whether the unit needs repair or replacement.

Replace a Worn-Out Garbage Disposal

Garbage disposals typically last 10-15 years with proper maintenance. If your unit is nearing the end of its lifespan and experiences frequent problems, replacement is likely the best option. When selecting a new garbage disposal:

  • Choose a reputable brand like Waste King, InSinkErator, or Moen
  • Look for a unit with at least 1/2 HP motor power
  • Seek out features like stainless steel grinding chambers, sound insulation, and overload protection
  • Buy disposal with a warranty of at least five years

Professional installation is recommended to ensure the new garbage disposal functions properly and safely.


Humming garbage disposal is annoying, but the cause is often easily fixed with some basic troubleshooting. The issue often stems from something simple like a jammed flywheel, a tripped reset button, or a clogged drain line. Taking the time to properly diagnose the problem and make any necessary repairs will have your disposal grinding food waste again in no time. If DIY efforts are unsuccessful, rely on a professional plumber to get your garbage disposal back in working order.

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