The average garbage disposal lasts 8-12 years.
But with proper care, yours can last 15 years or more. Neglect it, and you might be shopping for a replacement in just 5 years.
The difference comes down to understanding what your disposal can handle, what destroys it, and how to maintain it properly.
This guide covers everything Chattanooga homeowners need to know about garbage disposal care—from daily use to troubleshooting common problems.
How Garbage Disposals Work
Understanding the mechanics helps you use it correctly.
The Grinding Process
Despite what many people think, garbage disposals don’t have sharp blades. Instead:
- Impellers (blunt metal lugs) spin on a plate
- Food is flung against a grind ring by centrifugal force
- The grind ring breaks food into tiny particles
- Water flushes particles down the drain
Key insight: The disposal relies on water flow and centrifugal force, not cutting. This is why certain foods cause problems.
Motor Types
- Continuous feed: Runs while switch is on (most common)
- Batch feed: Requires lid to be in place to run (safer)
Horsepower Ratings
| HP | Best For |
|---|---|
| 1/3 HP | Light use, small households |
| 1/2 HP | Average use, most homes |
| 3/4 HP | Heavy use, larger families |
| 1+ HP | Heavy use, harder foods |
What You CAN Put in a Garbage Disposal
Your disposal can handle most soft food waste.
Safe Foods
- Soft fruits and vegetables (citrus, berries, cooked veggies)
- Small bones (chicken, fish—in moderation)
- Cooked meat scraps (small amounts)
- Bread and grains (small amounts)
- Soft leftovers
- Ice cubes (actually helps clean it)
- Citrus peels (freshens and cleans)
Best Practices
- Cut large items into smaller pieces
- Feed gradually rather than all at once
- Always run cold water before, during, and after
- Let it run until grinding stops completely
What You Should NEVER Put in a Garbage Disposal
These items cause jams, clogs, and premature failure.
Fibrous Vegetables
Fibers wrap around the impellers and jam the motor.
Avoid:
- Celery
- Asparagus
- Corn husks
- Artichokes
- Onion skins
- Rhubarb
Starchy Foods
Starches create a thick paste that clogs drains.
Avoid:
- Pasta (expands with water)
- Rice (expands with water)
- Potato peels
- Beans
Grease and Oil
Grease solidifies in pipes and causes clogs.
Avoid:
- Cooking oil
- Bacon grease
- Butter
- Fatty meat trimmings
Hard Items
These can damage the impellers and grind ring.
Avoid:
- Large bones (beef, pork)
- Fruit pits (peach, avocado, cherry)
- Shellfish shells
- Popcorn kernels
Non-Food Items
Should be obvious, but worth stating.
Never put in:
- Glass
- Metal
- Plastic
- Paper
- Rubber bands
- Twist ties
Other Problematic Items
- Coffee grounds – Accumulate in pipes
- Eggshells – Create gritty buildup (debated, but best avoided)
- Expandable foods – Anything that swells with water
Daily Use Best Practices
Follow these habits to maximize disposal life.
The Right Way to Use Your Disposal
- Turn on cold water (cold keeps grease solid for grinding)
- Turn on the disposal
- Feed food gradually (don’t dump everything at once)
- Continue running until grinding stops
- Run water 15-20 seconds more to flush particles
- Turn off disposal, then water
Why Cold Water?
Hot water melts grease, which then re-solidifies in your pipes. Cold water keeps grease solid so it gets ground up and flushed away.
Run It Regularly
Even if you don’t have food waste, run the disposal with water every few days. This prevents rust and corrosion and keeps parts moving freely.
Cleaning Your Garbage Disposal
Regular cleaning prevents odors and buildup.
Weekly Cleaning: Ice and Salt
Method:
- Pour 2 cups of ice into the disposal
- Add 1 cup of rock salt or coarse salt
- Run cold water
- Turn on disposal and run until ice is gone
Why it works: Ice and salt scour the grinding components, removing buildup.
Weekly Cleaning: Citrus Freshening
Method:
- Cut a lemon, lime, or orange into quarters
- Feed pieces into running disposal one at a time
- Run until completely ground
Why it works: Citrus oils cut grease and leave a fresh scent.
Monthly Deep Clean: Baking Soda and Vinegar
Method:
- Pour 1/2 cup baking soda into disposal
- Add 1 cup white vinegar
- Let fizz for 5-10 minutes
- Flush with hot water while running disposal
Cleaning the Splash Guard
The rubber splash guard collects gunk on the underside.
Method:
- Lift flaps and scrub underside with a brush
- Use dish soap and warm water
- Rinse thoroughly
Troubleshooting Common Problems
Before calling a plumber, try these fixes.
Problem: Disposal Won’t Turn On
Possible causes and fixes:
-
Check the power
- Is it plugged in?
- Check the circuit breaker
-
Press the reset button
- Located on the bottom of the unit
- Press firmly until it clicks
- Try the disposal again
-
Check the switch
- Wall switch may be faulty
- Try a different switch if available
If none of these work: The motor may have failed. Call a plumber.
Problem: Disposal Hums But Doesn’t Grind
The motor runs but the impellers are stuck.
Fix:
- Turn off the disposal immediately (running while jammed burns out the motor)
- Unplug the unit or turn off the breaker
- Use an Allen wrench in the hole at the bottom center
- Turn back and forth to free the jam
- Remove the obstruction with tongs (never your hand)
- Press reset button
- Restore power and test
Allen wrench size: Usually 1/4 inch. Many disposals come with one.
Problem: Disposal Drains Slowly
Water backs up in the sink.
Possible causes:
- Clog in the disposal
- Clog in the drain line
- Insufficient water during use
Fixes:
- Run disposal with plenty of water
- Use ice and salt cleaning method
- Check and clean the P-trap
- If still slow, the clog may be further down—call a plumber
Problem: Disposal Leaks
Check these locations:
- Top flange: Where disposal meets sink (may need resealing)
- Side connections: Dishwasher hose or drain pipe connections
- Bottom: Internal seal failure (usually means replacement)
Problem: Bad Odors
Causes:
- Food buildup on components
- Bacteria growth
- Inadequate water use
Fixes:
- Clean with ice and salt
- Clean with citrus
- Clean splash guard
- Run disposal longer with more water
When to Call a Plumber
Some problems require professional help.
Call a Plumber If:
- Disposal won’t reset after clearing jam
- Motor runs but impellers don’t move (even after unjamming)
- Persistent leaks from bottom of unit
- Electrical problems (sparks, burning smell)
- Disposal needs replacement
- Drain clogs you can’t clear
Disposal Replacement
When repair isn’t worth it, replacement costs:
| Component | Cost |
|---|---|
| Basic disposal (1/3-1/2 HP) | $75-$150 |
| Mid-range disposal (1/2-3/4 HP) | $150-$300 |
| Premium disposal (3/4-1 HP) | $300-$500 |
| Professional installation | $100-$200 |
Total replacement cost: $175-$700 depending on unit quality.
Garbage Disposals and Septic Systems
If you have a septic system, special considerations apply.
The Issue
Garbage disposals add solids to your septic tank, requiring more frequent pumping.
Recommendations
- Limit disposal use if you have septic
- Choose a septic-assist model (adds enzymes)
- Pump tank more frequently (every 2-3 years vs. 3-5)
- Avoid high-volume grinding sessions
Disposal Maintenance Schedule
Daily
- Run with cold water
- Feed food gradually
- Run 15-20 seconds after grinding stops
Weekly
- Ice and salt cleaning
- Citrus freshening
- Clean splash guard
Monthly
- Baking soda and vinegar deep clean
- Check for leaks
- Listen for unusual sounds
Annually
- Inspect mounting and connections
- Check for corrosion
- Consider professional inspection if disposal is 8+ years old
Key Takeaways
- Know what to avoid: Fibrous veggies, starches, grease, and hard items
- Always use cold water before, during, and after
- Feed gradually rather than dumping everything at once
- Clean weekly with ice, salt, and citrus
- Know how to reset and unjam before calling a plumber
- Run it regularly even when you don’t have food waste
- Replace when repair costs exceed 50% of new unit price
Need garbage disposal help? Find local Chattanooga plumbers who can repair or replace your garbage disposal.