Garbage Disposal Humming? Your 5-Step Guide to Fixing it (or Replacing It)

If you have a garbage disposal humming but not turning on, it almost always means the motor has power, but the blades are physically stuck. This is typically caused by a foreign object jamming the grinding components or a tripped internal safety breaker. You can often fix this yourself by cutting the power and using an Allen wrench to clear the obstruction manually.

It is a common and frustrating kitchen problem. You flip the switch to wash away food scraps, but instead of the usual roar, you get a low, electric hum. While it sounds serious, the solution is often simple and requires just a few minutes of your time.

In this guide, we'll walk you through the causes of this issue, the safe steps to fix it yourself, and how to decide if it's time to call a professional for your garbage disposal needs.

Before attempting any repairs, you must completely disconnect the appliance from its power source to prevent accidental startup and serious injury. Follow these two crucial steps to ensure your safety:

1. Turn Off the Wall Switch: Locate the switch that operates the garbage disposal and turn it to the "OFF" position.
2. Turn Off the Circuit Breaker: Go to your home's main electrical panel, find the breaker that controls the garbage disposal, and flip it to the "OFF" position. For added security, place a piece of tape over the breaker to signal that you are working on the circuit.

A humming sound indicates the motor is receiving electricity and trying to work, but something is preventing it from turning. The three most common reasons for this are a jam, a tripped reset button, or a failed motor.

Quick Reference Table: Here's a snapshot of the most common causes, their symptoms, fixes, and difficulty levels before we dive into the details.

Now, let's go through each cause in detail so you'll know exactly what's happening with your unit.

This is the most frequent culprit. An object like a fruit pit, chicken bone, silverware, or even fibrous food waste like celery stalks has become wedged between the impeller blades and the grinding chamber wall. The motor has enough power to make a sound but not enough torque to break through the obstruction, resulting in a jam.

Your disposal has a built-in overload protection feature to prevent the motor from overheating and burning out. When the motor struggles against a difficult jam, it draws excess current, which trips this internal garbage disposal reset button. This cuts power to the motor mechanism, but the main circuit may still be active, causing the hum.

In older units or after a particularly severe jam, the motor itself can fail. The internal bearings can seize from rust or wear, or an electrical component within the motor may have shorted out. This is the most serious cause and is a clear sign that the unit likely needs to be replaced by a professional.

Now that you understand the potential causes, it's time to resolve the problem. Follow these steps to safely diagnose and resolve the issue:

1. Ensure the Power is Off

This is the most important step and worth repeating. Before proceeding, confirm that the garbage disposal is disconnected from power at both the wall switch and the circuit breaker.

2. Look for the Reset Button

The garbage disposal reset button is a small red or black button on the bottom of the unit under the sink. Press this button firmly. If it is tripped, it will click and stay recessed. If it doesn't stay in, it wasn't the source of the problem.

3. Check for Obstructions from Above

With the power safely off, use a flashlight to look down into the sink drain. If you can see a loose object like a bone or piece of silverware, use pliers or tongs to carefully pull it out. Never put your hands or fingers down into the grinding chamber.

4. Manually Free the Jam from Below

This is the most effective way to fix a jammed garbage disposal. Find the hexagonal socket on the bottom of the disposal and insert a 1/4-inch Allen wrench. Firmly work the wrench back and forth, clockwise and counter-clockwise.

This manually turns the flywheel and impeller blades, which will break the jam free. Continue until the wrench can make a full, unobstructed circle.

5. Restore Power and Test Carefully

Once all tools are removed, it's safe to restore power. Turn the circuit breaker on first, then the wall switch. Run a strong stream of cold water and turn on the disposal. It should now spin freely.

If the steps above did not work, you will need to decide between calling a professional for a repair or getting a new unit.

You Should REPAIR If...

A repair is your best option if the disposal is less than five years old, it's a high-end model, or the problem is a simple fix for a plumber. A professional can often clear a stubborn jam or replace a faulty component for much less than the cost to replace a garbage disposal.

You Should REPLACE If...

You should plan for a replacement if the unit is leaking from its main housing (a sign of a failed seal), is over 10 years old, or the motor is seized and will not turn with the Allen wrench. Needing to press the reset button frequently is another key indicator that the motor is failing and a new unit is needed.

Here's a side-by-side look at the benefits and drawbacks of each option to make your decision easier:

While many jams can be fixed with these DIY steps, some problems require professional expertise. If you've tried these solutions and the disposal is still not working, or if you're not comfortable performing these steps yourself, it's time to call in an expert.

Our licensed technicians at Cactus Plumbing and Air can diagnose the issue quickly and handle everything from complex repairs to full replacements, ensuring your kitchen is back in working order. Call us today if you need a plumber in Scottsdale!

Your garbage disposal is humming because the motor has power, but the blades are stuck and cannot spin. This is almost always caused by a foreign object physically jamming the grinding mechanism.

The reset button is a small red or black button located at the bottom of the disposal unit, on the underside of the cylinder that is visible beneath your sink.

You can manually unjam a disposal by first turning off all power, then inserting a 1/4-inch Allen wrench into the socket on the very bottom of the unit. Working the wrench back and forth will manually turn the blades and dislodge the jam.

It is generally cheaper to repair a newer disposal with a minor issue. However, if the unit is more than 10 years old, is leaking from its main body, or has a seized motor, it is more cost-effective to replace it.

If your sink backs up with water, it indicates a clogged drain line further down the plumbing. The disposal is likely working correctly, but the wastewater has nowhere to go. This problem requires professional drain cleaning, faucet & fixture services.