How to Fix a Garbage Disposal — Complete Troubleshooting Guide

Yes, you can fix your garbage disposal yourself. Most problems take under 10 minutes to solve with basic tools you probably already have. This guide walks you through every common fix — from a simple reset to unjamming a stuck flywheel.

Quick Diagnosis — What’s Your Disposal Doing?

Before grabbing any tools, figure out exactly what’s happening. The symptom tells you the cause — and the fix.

Find your problem below and jump straight to the fix:

Makes a humming noise but won’t spin? → Fix 2: Unjam the Flywheel
Completely silent when you flip the switch? → Fix 4: Restore Power
Runs but drains slowly? → Fix 3: Unclog the Drain
Leaking water under the sink? → See our guide on leaking disposal repair

Good news: Most disposal problems have a simple fix. Start with Fix 1 below — the reset button solves the majority of issues in about 30 seconds.

Not sure which symptom you have? Turn on the disposal and listen. A humming sound means the motor works but something is blocking it. Complete silence means it’s a power issue. Running normally but backing up means a clog downstream.

What You’ll Need

Gather these before you start:

1/4” Allen wrench — This specific size fits most disposals. Check your junk drawer — one usually comes with the unit.
Flashlight — To see inside the disposal and under the sink
Pliers or tongs — For retrieving objects (never use your hands)
Plunger — A flat-bottom sink plunger, not a toilet flange plunger

You likely won’t need all of these. The reset button fix requires no tools at all.

Fix 1: Reset the Disposal (30 Seconds)

Try this first. The reset button fixes most disposal problems instantly.

Your disposal has a built-in safety switch that trips when the motor overheats or overloads. When this happens, you just need to reset it.

Here’s how:

Turn off the wall switch — Make sure the disposal is off
Wait 5 minutes — If the motor was running or hot, let it cool down
Find the reset button — Look on the bottom of the disposal unit under your sink. It’s a small red or black button, about the size of a pencil eraser.
Press the button firmly — Push until you feel it click and stay in
Test it — Turn on cold water, then flip the wall switch

If the disposal runs normally, you’re done. If the reset button pops back out immediately or won’t stay pressed, there’s likely a jam that needs clearing first.

For more details, see our complete guide to reset the disposal.

Fix 2: Unjam a Humming Disposal

Symptom: You hear a humming sound when you turn on the disposal, but the blades don’t spin.

This means the motor is working, but something is jamming the flywheel (the spinning plate with the blades). This is the second most common problem after a tripped reset.

Safety First: Turn off the wall switch AND the circuit breaker before working on a jam. Never put your hand inside the disposal, even when the power is off.

Method 1: Allen Wrench (Best Option)

Find the hex-shaped hole on the bottom center of the disposal
Insert a 1/4” Allen wrench into the hole
Rotate the wrench back and forth — you’ll feel resistance at first
Keep rotating until the flywheel moves freely in both directions
Use a flashlight to look inside the disposal from above
Remove any visible debris with pliers or tongs
Press the reset button
Restore power and test with cold water running

Method 2: Wooden Spoon (No Allen Wrench)

Insert a wooden spoon handle into the disposal from the top
Press it against one of the impeller blades
Push to rotate the flywheel manually
Work it back and forth until it moves freely
Remove debris, reset, and test

Common jam culprits: Bones, fruit pits, silverware, glass shards, and bottle caps. If your disposal is humming, a jammed disposal is almost always the cause.

Prevention tip: Always run cold water before, during, and after using the disposal. Cold water keeps grease solid so it gets chopped up rather than coating the blades and causing buildup that leads to jams.

Fix 3: Unclog a Slow-Draining Disposal

Symptom: The disposal runs, but water drains slowly or backs up into the sink.

A clog is usually in the drain line below the disposal, not in the disposal itself.

Step 1: Try Running the Disposal

Sometimes debris just needs to be cleared:

Turn on cold water
Run the disposal for 30 seconds
Keep water running for another 15 seconds after turning off the disposal

Step 2: Plunge It

If that doesn’t work:

Fill the sink with 3-4 inches of water
If you have a double sink, seal the other drain with a wet rag
If a dishwasher is connected, clamp the drain hose to prevent backflow
Use a flat-bottom plunger (not a toilet plunger)
Plunge vigorously 15-20 times
Check if water drains
Run the disposal with water to clear remaining debris

Step 3: Clean the P-Trap

For stubborn clogs:

Place a bucket under the P-trap (the curved pipe under the sink)
Loosen the slip nuts and remove the trap
Clean out any debris — grease buildup is common
Reassemble and test

Warning: Never use chemical drain cleaners like Drano in a garbage disposal. They can damage the seals and create a dangerous splash hazard.

What causes disposal clogs? The most common culprits are grease, fibrous foods (celery, asparagus, corn husks), and starchy foods that expand (pasta, rice, potato peels). These build up over time in the drain line below the disposal unit itself.

Preventing future clogs: Run the disposal with cold water for 15-20 seconds after all food is ground up. Once a week, grind ice cubes to clean the blades, followed by citrus peels to freshen the drain.

For persistent drainage issues, see our clogged disposal guide.

Fix 4: Restore Power to a Silent Disposal

Symptom: Nothing happens when you flip the switch — no sound at all.

When a disposal is completely silent, it’s usually a power problem, not a broken disposal.

Check these in order:

Is it plugged in? — Look under the sink for the outlet. Make sure the plug is secure.
Check the GFCI outlet — Many under-sink outlets are GFCI protected (the outlet with “Test” and “Reset” buttons). Press the Reset button on the outlet itself.
Check the circuit breaker — Go to your electrical panel and look for a tripped breaker. If one is in the middle position, flip it fully off, then back on.
Test the outlet — Plug in a lamp or phone charger. If it doesn’t work, the outlet is the problem, not the disposal.

If the outlet has power but the disposal still won’t run, try the reset button on the disposal itself.

For more on power issues, including when to call an electrician, see our electrical troubleshooting guide.

When to Replace Instead of Repair

Sometimes a disposal can’t be fixed. Here’s how to know when it’s time for a new one:

Signs your disposal needs replacing:

Burning smell — This indicates motor damage. Once you smell burning, the motor is likely done.
Reset button won’t stay in — Even after clearing any jams, if the button keeps popping out, the motor may be burned out.
Age — Disposals over 10 years old are candidates for replacement, especially if they’re having multiple problems.
Leaking from the bottom — This usually means internal seals have failed. Seal replacement isn’t practical — a new unit is more cost-effective.

Cost comparison:

Professional repair: $75-150 (often not worth it)
New disposal: $80-300 depending on power and features
Professional installation: $150-200

If your disposal is old and showing multiple symptoms, replacement usually makes more sense than repair.

Choosing a replacement: For most households, a 1/2 HP disposal handles everyday food waste. If you cook frequently or have a large family, consider a 3/4 HP or 1 HP model. InSinkErator and Moen are the most common brands — parts and support are easy to find. Continuous-feed models (turn on with a switch) are standard; batch-feed models (activated by a lid) are safer if you have children.

DIY vs. professional installation: If you’re replacing an existing disposal with the same size, DIY installation takes about an hour. However, if you need new electrical work or plumbing modifications, hire a professional.

Tools Every Homeowner Should Have

Keep these on hand for future disposal issues:

Disposal wrench or 1/4” Allen wrench — For clearing jams. Most disposals come with one — check your junk drawer or under the sink.
Flashlight — Essential for seeing inside the unit and under the sink
Flat-bottom plunger — Different from a toilet plunger. Works better on sink drains.
Basic pliers or tongs — For retrieving dropped items safely

With these four items, you can handle 90% of garbage disposal problems yourself.

FAQ

Can I fix my garbage disposal myself?

Yes. About 90% of garbage disposal problems can be fixed in under 10 minutes with basic tools. The most common fixes — resetting and unjamming — require only an Allen wrench or no tools at all.

Why is my garbage disposal humming but not spinning?

The flywheel is jammed. Something is stuck between the blades and the grinding ring, preventing rotation while the motor runs. Insert a 1/4” Allen wrench into the hole on the bottom of the disposal and rotate back and forth to free it.

How do I fix a garbage disposal that stopped working?

Start by pressing the reset button on the bottom of the unit. If the disposal is completely silent, check the power: make sure it’s plugged in, reset the GFCI outlet, and check the circuit breaker. If it hums but doesn’t spin, it’s jammed and needs to be freed with an Allen wrench.

Is it worth fixing an old garbage disposal?

If your disposal is over 10 years old or leaking from the bottom, replacement is usually the smarter choice. New units cost $80-300 and are more efficient and quieter than older models. For simple issues like jams or resets, fixing is always worth trying first regardless of age.

What can I put in a garbage disposal?

Most soft food scraps are fine: vegetable trimmings, fruit, cooked meat, bread, and small bones (chicken bones are okay, beef bones are not). Avoid fibrous foods (celery, corn husks), starchy foods that expand (pasta, rice), grease and oil, coffee grounds in large amounts, and non-food items.

Why does my garbage disposal smell bad?

Odors come from food residue stuck on the blades and inside the grinding chamber. To clean it, pour a half cup of baking soda into the disposal, add a cup of white vinegar, let it fizz for 10 minutes, then flush with hot water while running the disposal. For ongoing freshness, grind citrus peels weekly.