How to Fix 6 Common Garbage Disposals Problems
For Northern California Homeowners
Garbage disposals are a modern kitchen convenience—until they stop working.
Flipping the switch and only hearing a humming sound (or nothing at all), can be frustrating.
Around the holidays, calls about broken garbage disposals are common for Sacramento plumbers.
Luckily, many garbage disposal problems can be fixed without calling a professional plumber.
With a little know-how and some simple tools, you can keep your garbage disposal running smoothly.
Here are the most common reasons your garbage disposal is not working, and advice on how to fix them yourself.
Note: Never pour chemical drain cleaners into a garbage disposal. The harsh chemicals can damage the disposal unit.
1. The Disposal Unit Won’t Turn On
The Problem:
You flip the switch, and nothing happens. No noise, no hum, nothing.
The Fix:
This is usually a power source problem.
Check these steps:
- Check the power: Look under your sink to check if the disposal unit is plugged in. It might seem silly, but plugs can come loose.
- Garbage disposal reset: Most disposal units have a small red reset button on the bottom. Press the reset button. If it stays in, try flipping the switch again.
- Check the circuit breaker: If the reset button doesn’t work, your breaker might have tripped.
If none of this works, the motor might be burned out.
In this case, you may need to replace the disposal unit.
Or call a professional plumber for a garbage disposal repair or replacement.
2. The Garbage Disposal is Humming but Not Grinding
The Problem:
You flip the switch, and instead of the sound of grinding, you hear a humming sound.
The Fix:
This usually means a jammed or clogged garbage disposal.
Here’s what to do:
- Turn off the power. Be safe! Unplug the disposal unit and flip the circuit breaker to make sure it’s completely off.
- Use an Allen wrench. Most disposals come with an Allen wrench. Insert it into the hex-shaped hole underneath the bottom of the disposal unit. Turn the wrench clockwise to free the jam.
- Remove the blockage. Shine a flashlight down the drain. Never stick your hand inside! Use pliers or tongs to remove whatever is stuck.
Reset the disposal once the jam is cleared.
Then plug it in and turn the power back on.
3. The Disposal Unit is Leaking
The Problem:
Water is dripping under your sink, and it’s coming from your garbage disposal unit.
The Fix:
Leaks usually come from one of three places:
- The sink flange. This is where the disposal connects to the sink. Tighten the mounting bolts. Or remove the unit from the mounting flange, reseal with plumber’s putty, then remount the unit.
- The drainpipe. Check where the disposal connects to the pipe. Tighten the screws, or replace the gasket if it’s worn out.
- The garbage disposal itself. If the unit is cracked or corroded, it’s time to replace it.
Don’t ignore disposal leaks.
They can cause bigger problems if not addressed.
4. Garbage Disposal Smells Bad
The Problem:
Your disposal unit grinds food scraps fine, but it smells terrible.
The Fix:
This is a buildup of food particles, but it’s easy to fix:
- Flush it. Add a few drops of dish liquid and run hot water into the disposal. Let it grind for 30 seconds.
- Deodorize it. Toss in a handful of ice cubes and a few lemon peels, then run the disposal. The ice cleans the blades, and the lemon peels deodorize.
- Deep clean it. If the smell persists, use a long brush to scrub the inside of the disposal. Never stick your hand inside the disposal!
5. Disposal Not Grinding Food Waste Well
The Problem:
The disposal turns on, but it’s not breaking down the food waste.
The Fix:
Blades don’t technically “sharpen,” but buildup can impact how well they function.
Here’s how to fix it:
- Grind ice cubes. Toss in a few handfuls of ice and let the disposal do its thing. This helps remove any buildup and keeps the blades in shape.
- Avoid problem foods. Don’t grind fibrous foods (like celery or corn husks), grease, or large bones. These can damage the blades and clog the unit.
- Grind small amounts at a time. If you’re peeling potatoes, don’t wait until you’re all done and try to grind all the peels at once. Grind up the peels a little at a time.
6. The Sink is Backed Up
The Problem:
Food scraps from the garbage disposal are backing up into your sink.
The Fix:
This usually means there’s a clog in the disposal unit or in the drainpipe.
Try this:
- Use a Plunger: Place the plunger firmly over the garbage disposal drain. Push down to create a strong seal, then plunge with steady, strong force (not speed). After a few tries, check if the water starts draining.
- Add Hot Water: Hot water can melt grease or oil that might be causing the clog. Heat a large pot of water until it’s almost boiling. Carefully pour the hot water directly into the garbage disposal drain. Wait a few minutes and try running the disposal again.
- Clear the P-Trap: The P-trap is the U-shaped pipe under your sink. Clogs often settle there, so clearing it out can solve the problem.
- Step 1: Place a bucket under the P-trap to catch water.
- Step 2: Have some towels ready—it might get a little messy.
- Step 3: Loosen the connections on the P-trap and carefully remove it.
- Step 4: Check for clogs and rinse it out before reattaching it.
Put everything back together and test the drain.
- Baking Soda and Vinegar: Pour about half a cup of baking soda into the drain. Follow it with half a cup of vinegar. Let the mixture fizz for about 15 minutes. Flush with hot water and see if the clog clears.
- For Two-Sided Sinks: If your sink has two drains, one with a disposal and one without, block the other drain. This will help create a vacuum for plunging.
- Plug the non-disposal drain with a stopper.
- Then, use a plunger on the disposal drain.
Sometimes, despite your best efforts, the garbage disposal just won’t cooperate.
If the motor is fried, the unit is cracked, or you just can’t figure out what’s wrong, it’s time to call a pro.
A licensed plumber can diagnose garbage disposal issues and get your kitchen back in working order quickly.
At Millennium Plumbing Specialist, we’ve seen it all when it comes to garbage disposals.
Whether you need a quick repair or a full replacement, we’re here to help.
We provide plumbing services in Sacramento County and surrounding counties.
