I’m Konstantin Lozovyi, Owner and Master Plumber (License #MP210432) at K L Contractor Plumbing Inc., serving Marietta, GA and the greater Metro Atlanta area. In this guide, we walk through the eight most common reasons your garbage disposal stopped working and show you what you can safely fix yourself and what needs a professional.
Why Your Garbage Disposal Stopped Working
Contents
- 1 Why Your Garbage Disposal Stopped Working
- 2 Problem 1: Disposal Hums but Won’t Spin
- 3 Problem 2: Disposal Won’t Turn On at All
- 4 Problem 3: Disposal Leaks from the Bottom
- 5 Problem 4: Disposal Drains Slowly or Backs Up
- 6 Problem 5: Disposal Makes Grinding or Rattling Noise
- 7 Problem 6: Disposal Smells Bad
- 8 Problem 7: Disposal Trips the Breaker
- 9 Problem 8: Disposal Works but Won’t Grind Food
- 10 Frequently Asked Questions
- 11 Get Your Disposal Fixed the Right Way
A garbage disposal that quits on you is one of the most frequent kitchen plumbing calls we get. In my 20+ years as a Master Plumber, I’ve found that most failures fall into a few categories: electrical issues, mechanical jams, worn-out parts, or simple clogs.
Some of these problems take less than five minutes to solve at home. Others point to a unit that needs repair or replacement. The key is matching symptoms to the right problem, and we cover all eight below.
Problem 1: Disposal Hums but Won’t Spin
If your garbage disposal is humming but not working, the motor gets power but the flywheel inside is stuck. This is the most common disposal problem we see in Marietta homes.
What Causes It
Food scraps, a small bone fragment, or a piece of silverware can wedge between the impeller plate and the shredder ring. The motor tries to spin, but the obstruction holds it in place.
How to Fix a Jammed Garbage Disposal
- Turn off the disposal and unplug it. If your unit is hardwired, flip the breaker.
- Find the hex socket on the bottom of the unit. Most disposals have a 1/4-inch hex (Allen wrench) socket on the bottom plate. Many brands include a wrench with the unit.
- Insert the Allen wrench and rotate it back and forth. You will feel resistance at first. Keep working it until the flywheel moves freely.
- Remove the obstruction. Use tongs or long-nose pliers to pull out whatever jammed the impellers. Never use your fingers.
- Press the reset button on the bottom of the disposal. It is a small red or black button that pops out when the motor overloads.
- Restore power and test. Run cold water first, then flip the switch.
If the flywheel still will not move, or if the unit jams repeatedly, the internal components may be worn. Call a plumber for a closer look.
Problem 2: Disposal Won’t Turn On at All
A garbage disposal not turning on is a different situation from one that hums. No sound at all usually means no power is reaching the motor.
Steps to Check
- Press the reset button. The thermal overload switch trips more often than people think, especially after a jam or heavy use. You will find the button on the bottom of the unit.
- Check the wall switch. Some disposal switches wear out or develop loose wire connections. Toggle it off and on. If it feels loose or floppy, the switch may need replacement.
- Check the circuit breaker. Disposals typically share a circuit with the dishwasher. Look in your electrical panel for a tripped breaker. Reset it once. If it trips again immediately, call a licensed electrician or plumber.
- Test the outlet. If your disposal plugs into an outlet under the sink, try plugging something else into that outlet to confirm it has power.
If none of these steps restore power, the issue could be a faulty switch, a wiring problem, or a burned-out motor. We recommend calling a licensed professional because working with electrical wiring under a wet sink carries real risk.
Problem 3: Disposal Leaks from the Bottom
A garbage disposal leaking from the bottom of the unit, rather than from a pipe connection, usually means the internal seal has failed or the body has cracked.
Common Causes
- Worn-out internal seal. The shaft seal between the motor and the grinding chamber breaks down over time, especially on units older than eight to ten years.
- Cracked housing. Corrosion from years of moisture and food acids can weaken the disposal body until it develops small cracks.
- Loose mounting flange. Sometimes what looks like a bottom leak actually comes from the sink flange at the top, with water running down the outside of the unit.
What We Recommend
Bottom leaks from a failed seal or cracked body almost always mean replacement rather than repair. The cost to reseal an older disposal usually comes close to the price of a new unit. If your disposal is more than seven or eight years old and leaking from the housing, a new one will give you better performance and a full warranty.For more on handling water under your kitchen sink, see our guide on how to unclog a kitchen sink with a disposal.
Problem 4: Disposal Drains Slowly or Backs Up
A disposal that grinds fine but drains slowly has a clog downstream, not a disposal problem. This is one of the most misdiagnosed issues we see on service calls.
Where the Clog Usually Sits
- The discharge pipe. This short pipe runs from the side of the disposal to the drain trap. Grease and food particles build up here over months.
- The P-trap. The curved pipe section under your sink traps debris, especially if starchy or fibrous foods go through the disposal regularly. Items like eggshells, potato peels, and coffee grounds are common offenders.
- The drain line beyond the trap. Older homes in Marietta sometimes have corroded galvanized drain lines that catch food waste and narrow the pipe over time.
What to Do
Run the disposal with plenty of cold water for 15 to 20 seconds after the grinding stops. This flushes waste further down the line. If the backup has already happened, try plunging the disposal with a flat-bottom plunger (not a flange plunger).
For recurring slow drains, the problem is usually deeper in the line. Our drain cleaning service uses a cable machine or hydro jetting to clear the full line. You can also read about the most common kitchen sink clog causes to help prevent future backups.
Problem 5: Disposal Makes Grinding or Rattling Noise
Loud, unusual noises from a disposal almost always mean something is inside the chamber that should not be there.
Most Likely Culprits
- A piece of glass, a bottle cap, or a small utensil bouncing around inside the chamber
- A loose mounting screw
- A worn-out shredder ring that allows the impellers to wobble
How to Address It
Turn off the disposal and disconnect the power. Use a flashlight to look inside the chamber from above. If you spot a foreign object, remove it with tongs or pliers. Never reach in with your fingers because the impellers have sharp edges.
If you find nothing and the noise continues, the internal components may be worn. A metallic scraping sound with no visible foreign object usually points to a failing shredder ring or loose impeller plate. Replacement is typically more cost-effective than repair at that point.
Problem 6: Disposal Smells Bad
A foul smell from your garbage disposal does not mean the unit is broken. It means food residue has built up on the impellers, shredder ring, and chamber walls.
Why It Happens
Disposals grind food into fine particles, but thin layers of residue stick to every internal surface. Grease coats everything and traps other food particles. In Georgia’s warm and humid climate, bacteria break down that residue quickly and produce strong odors.
Cleaning Methods That Work
- Ice and salt. Drop a cup of ice cubes and half a cup of coarse salt into the disposal. Run it with cold water for 30 seconds. The ice and salt scour the internal surfaces.
- Baking soda and vinegar. Pour half a cup of baking soda into the disposal, followed by a cup of white vinegar. Let it fizz for five minutes, then flush with hot water.
- Citrus peels. Grind a few lemon or orange peels after cleaning to leave a fresh scent.
- Regular flushing. Run your disposal with cold water for 15 to 20 seconds after every use. This one habit prevents most odor problems.
Avoid commercial drain cleaners. They damage disposal components and corrode pipes over time.
Problem 7: Disposal Trips the Breaker
If your disposal trips the circuit breaker every time you turn it on, the problem is electrical and you should stop trying to reset and run it.
What Causes This
- Moisture in the wiring. Water under the sink can reach electrical connections, especially if there is a slow leak you have not noticed.
- A short circuit in the motor. Internal wiring insulation breaks down as disposals age. Once it fails, the motor shorts to ground and trips the breaker.
- An overloaded circuit. If the disposal shares a circuit with other high-draw appliances running at the same time, the breaker may trip from total load.
What to Do
A breaker that trips once after a hard jam is usually just the overload protection doing its job. Wait a few minutes, reset the breaker, and try again. But a breaker that trips every time you flip the disposal switch points to a wiring issue or a failing motor. Do not keep resetting a breaker that trips repeatedly because that creates a fire risk. Call a licensed professional.
Our team handles both the plumbing and the electrical connections during garbage disposal repair and replacement.
Problem 8: Disposal Works but Won’t Grind Food
The disposal turns on, the motor spins, water drains, but food sits in the chamber barely touched. This confuses a lot of homeowners because the unit seems to run fine.
Two Common Causes
Worn impellers. The impellers (sometimes called lugs) are small metal pieces on the spinning plate at the bottom of the chamber. They use centrifugal force to throw food against the stationary shredder ring, which does the actual grinding. Over years of use, the impellers wear down and lose the clearance they need to work effectively.Undersized unit. A 1/3-horsepower disposal may handle a single person’s kitchen waste, but a family of four will overwhelm it quickly. The motor runs, but it cannot generate enough force to grind the volume of food going in.
Frequently Asked Questions
Can I use my hand to remove something stuck in the disposal?
No. Always use tongs, pliers, or a similar tool. The impellers have sharp edges that can cut you even with the power off. Disconnect the power completely before reaching inside with any tool.
How long should a garbage disposal last?
Most residential disposals last eight to twelve years with normal use. Units that handle heavy food waste or run without enough water wear out faster. Higher-horsepower models with stainless steel grinding components generally outlast entry-level units.
Should I use hot or cold water when running the disposal?
Use cold water. Cold water keeps grease and fats solid so the disposal can chop them and flush them through the drain. Hot water melts grease, which re-solidifies further down the pipe and causes clogs.
Is it worth repairing a disposal, or should I just replace it?
If the disposal is under five years old and the problem is minor, repair makes sense. For older units with leaks, motor issues, or worn grinding components, replacement is almost always the better investment.
Get Your Disposal Fixed the Right Way
If your garbage disposal is not working and these troubleshooting steps did not solve the problem, our team is ready to help. We diagnose the issue, explain your options, and give you a written estimate before we start any work.
Call K L Contractor Plumbing Inc. at (404) 637-2796 or visit klplumbing.com to schedule a garbage disposal repair appointment. We serve Marietta, Kennesaw, Roswell, Smyrna, and communities across Metro Atlanta.