Garbage Disposal Fundamentals
When used correctly, a garbage disposal makes cleanup fast, prevents food waste from accumulating in your trash, and helps reduce kitchen odors.
A garbage disposal is one of the most useful appliances in your kitchen, turning food scraps into groundings that safely travel through your home’s plumbing. When used correctly, a garbage disposal makes cleanup fast, prevents food waste from accumulating in your trash, and helps reduce kitchen odors. But understanding how disposals work, what they can and can’t handle, and how to maintain them properly helps you protect your plumbing, avoid clogs, and extend the life of your system.
This complete guide explains garbage disposal mechanics, common dos and don’ts, troubleshooting tips, maintenance best practices, and when professional help may be needed. Whether you’re a new homeowner or just want to use your disposal more effectively, these fundamentals will keep your kitchen running smoothly.
How Garbage Disposals Work
A garbage disposal connects directly to your kitchen sink drain and uses a spinning impeller plate — not sharp blades — to break food waste into tiny particles that can safely pass through your drain and sewer system. When the disposal is activated, an electric motor spins the impeller, forcing food against a stationary shredding ring. The ground particles then flow out through the drain with the help of running water.
While it may seem like a food blender, a disposal doesn’t actually cut food with knives. Instead, it relies on centrifugal force to smash and grind waste into small fragments. Understanding this difference helps you realize why some items should never be put down a disposal.
Items You Can Put in a Garbage Disposal
When used correctly, a garbage disposal handles many common food scraps without issue:
• Soft fruits and vegetables — like melon rinds, peeled potatoes, and tomato scraps
• Leftover cooked foods — without large bones or hard bits
• Coffee grounds — in small amounts
• Small fruit peels — like citrus peels for a fresh scent
• Slowly dissolving foods — such as cooked rice or oatmeal in moderation
Running cold water during disposal use helps push particles through the system and prevents grease from sticking to pipes. Cold water also helps solidify any fats so they can be ground up more effectively, rather than melting and coating pipe walls.
Items You Should Not Put in a Garbage Disposal
Even though disposals handle many foods, there are several items that can damage the unit, clog drains, or lead to foul odors:
Grease, Fats, and Oils
Liquids that are liquid at warm temperatures but solidify when cooled — like bacon grease or cooking oils — should never go down the drain. These substances stick to pipes and the inside of the disposal, causing buildup and blockages over time.
Fibrous Vegetables
Fibrous foods like celery, corn husks, artichokes, asparagus stalks, and onion skins can wrap around the impeller and jam the disposal. The long fibers resist grinding and can tangle inside the unit.
Hard Items
Bone fragments, fruit pits, nutshells, and metal objects should never be put in a garbage disposal. Hard items can chip or crack the shredding ring, damage the impeller plate, or cause motor strain.
Starchy Foods
Rice, pasta, and potato peels swell with water and turn into pasty clogs rather than being ground and flushed away. These substances are better suited for compost or trash disposal.
Avoiding problematic items protects your unit and keeps your drains flowing freely.
Running the Disposal Correctly
Correct operation improves performance and prevents strain on your pipes:
• Turn on cold water first — start the flow before activating the disposal.
• Feed food gradually — small bits at a time prevent overload.
• Grind with water running — keep cold water running throughout grinding and for a few seconds after.
• Avoid chemical drain cleaners — these can damage seals, gaskets, and the disposal’s interior.
Cold water and gradual feeding allow the disposal to work efficiently and flush debris through the drain without creating pressure points.
Common Garbage Disposal Problems
Even with correct use, issues may arise. Here are common problems and how to address them:
Disposal Won’t Turn On
If nothing happens when you flip the switch, it may be a power issue. Check the outlet, reset the disposal’s overload button (often located on the bottom of the unit), and ensure the circuit breaker hasn’t tripped.
Disposal Hums but Doesn’t Grind
A humming sound without grinding usually means the impeller is jammed. Turn off the disposal and power at the breaker, then use a disposal wrench or hex key in the bottom slot to gently free the jam.
Frequent Clogs or Slow Drainage
This often indicates improper use (too much food at once, grease buildup, or the use of non-disposable items). Removing visible obstructions, flushing with hot water, and using a plunger for clogs help clear blockages.
Foul Odors
Trapped food debris often causes bad smells. Regular cleaning — scrubbing the splash guard and running citrus peels through the disposal — helps maintain freshness.
Maintenance Tips That Extend Disposal Life
Routine maintenance keeps your garbage disposal clean, efficient, and odor-free:
• Clean with ice cubes: Ice helps knock off buildup inside the chamber.
• Use citrus peels: Lemon or orange peels freshen odors naturally.
• Avoid harsh chemicals: Chemical cleaners can corrode internal parts.
• Flush with cold water: Always use cold water when grinding food waste.
• Avoid dumping grease: Never pour cooking oils or fats down your sink.
These habits reduce buildup, prevent odors, and help your disposal function at its best.
When to Call a Professional Plumber
Some issues signal a need for professional plumbing service:
• Persistent clogs that plunging and snaking don’t fix
• Disposal leaks under the sink
• Burning smells or unusual noises during operation
• Electrical issues or frequent resets
• Complete disposal failure
A licensed plumber can diagnose internal damage, replace worn components, or install a new disposal if necessary.
Garbage Disposal Use and Care Questions Homeowners Should Know
What should not go down my garbage disposal?
Avoid grease, fibrous vegetables, large bones, fruit pits, large amounts of coffee grounds, and starchy foods like rice and pasta. These items can expand, bind, or stick to pipes and cause clogs.
Why does my disposal make a humming sound?
A humming sound usually means the disposal is jammed or overloaded. Turning off power at the switch or breaker and using the disposal wrench to free the impeller often resolves the issue.
How do I remove foul odors from my disposal?
Run cold water while cleaning the splash guard, grind citrus peels, and use ice cubes to dislodge trapped food. These steps help reduce odor causing residue inside the unit.
Can a garbage disposal clog my drain?
Yes. Improper disposal of grease or fibrous food waste can build up in drain lines. Feeding waste gradually and flushing with cold water helps prevent clogs.
When should I call a plumber for disposal problems?
Contact a plumber if you notice leaks, frequent clogs, unusual noises, electrical issues, or if basic troubleshooting does not restore normal operation.
MNS Plumbing is here to help with all your garbage disposals, dishwasher installation, water purification, and other plumbing installation requirements. Serving the entire Phoenix, AZ Greater Metro Area, you can count on us to keep your home safe all year round.
