Turn on the water before you start the disposer
Start cold water flowing at full pressure before you flip the switch. The water does two things: it helps the disposer grind the food into small particles, and it carries those particles down the drain so they don't pile up inside the unit. Keep the water running the entire time the disposer is on, and continue running it for about 30 seconds after you turn the disposer off. This final flush clears any remaining food from the chamber.
Cold water is better than hot water because it keeps grease solid so the disposer can break it into smaller pieces. Hot water melts grease, which then coats the inside of your pipes and can cause clogs further down the line.
Key Takeaways
- Always run cold water at full pressure before, during, and for 30 seconds after using the disposer.
- Feed food in small amounts through the drain opening while the disposer is running, never with the water off.
- Avoid putting bones, pits, shells, fibrous vegetables, grease, and starchy foods like rice or pasta down the disposer.
- If the disposer jams or stops grinding, turn it off when ready and use tongs or pliers to remove the blockage—never put your hand inside.
- Run the disposer for a few seconds with just water and ice cubes once a month to clean the grinding chamber.
Feed food in small pieces while the water and disposer are running
Drop food scraps into the drain opening in small handfuls, not all at once. A piece the size of a walnut is a good target. The disposer needs time to grind each batch before you add more. If you dump a large amount in at once, the motor has to work much harder and may jam or overheat.
Never turn on the disposer and then add food. Always start the water and disposer first, then feed the food in. This order prevents food from sitting in the chamber without being ground, which can cause odors and attract bacteria.
Foods that jam or damage the disposer
Bones, pits, and shells are too hard for most home disposers to grind. Chicken bones, peach pits, and nutshells will either jam the blades or break them. Remove these by hand before scraping your plate.
Fibrous vegetables like celery, corn husks, and onion skins wrap around the grinding mechanism and jam it. Asparagus, artichoke leaves, and carrot tops have the same problem. Throw these in the trash or compost instead.
Grease and oils should never go down any drain, including the disposer. They cool and solidify inside your pipes, creating blockages that are expensive to clear. Let grease cool in a pan, then wipe it into the trash with a paper towel.
Starchy foods like rice, pasta, and potatoes turn into a paste when wet and can clog the drain. Bread, oatmeal, and flour have the same effect. These belong in the trash or compost.
What to do if the disposer jams or stops grinding
Turn off the disposer when ready and turn off the switch. Do not reach into the drain. If you can see the blockage, use tongs, pliers, or a wooden spoon to pull it out from above. Never put your fingers or a metal utensil into the chamber while the power is on, even if the motor has stopped.
If you cannot see or reach the jam, try this: turn off the disposer, fill the sink with a few inches of cold water, then turn the disposer back on for two or three seconds. Sometimes the water pressure will dislodge a stuck piece. If that does not work, turn it off again and wait a few minutes. The motor may have tripped a thermal overload switch to protect itself from overheating. After it cools, try again.
If the disposer still will not run or makes a grinding noise without breaking down food, the blades may be damaged or the motor may have failed. At that point, you will need to call a plumber or replace the unit.
Monthly cleaning with ice and water
Once a month, run the disposer with just ice cubes and cold water to scour the inside of the grinding chamber. Fill a small cup with ice cubes, turn on the cold water at full pressure, turn on the disposer, and drop the ice in slowly. The ice is hard enough to clean the blades and chamber walls without damaging them. Run the disposer for about 10 seconds after the last ice cube is ground.
This straightforward step removes buildup and odors that can develop inside the unit. It also keeps the blades sharp so they grind food more efficiently.
Signs your disposer needs repair or replacement
A disposer that hums but does not grind has a jammed blade or a broken motor coupling. A disposer that leaks from the bottom or sides has a cracked chamber or loose connections. A disposer that smells bad even after cleaning may have food trapped in a part you cannot reach, or the seal may be failing.
If your disposer is more than 10 to 15 years old and starts having problems, replacement is often cheaper than repair. Newer models are more efficient and use less water. If your disposer is newer and has only recently started acting up, a plumber can usually fix it for less than the cost of a new unit.
Common mistakes that shorten the life of your disposer
Running the disposer without water is the fastest way to damage it. The grinding mechanism needs water to cool it and carry food away. Running it dry creates friction and heat that can warp the blades and burn out the motor.
Putting large amounts of food in at once overloads the motor and can cause it to jam or shut down. Feeding food slowly in small pieces keeps the motor running smoothly and prevents blockages in your drain.
Using hot water with grease is another common mistake. The hot water melts the grease so it flows down the drain, but it then cools and hardens in your pipes, creating a clog that the disposer did not cause but you will have to pay to fix.
Frequently Asked Questions
Can I put eggshells down the disposer?
No. Eggshells are made of calcium and do not break down the way food does. They pass through the disposer in large pieces and can jam the drain or get stuck in the pipes. Throw eggshells in the trash or compost.
What should I do if the disposer smells bad?
Run cold water and ice cubes through it as described in the monthly cleaning section. If the smell persists, pour half a cup of baking soda down the drain, let it sit for 30 minutes, then run the disposer with cold water for 10 seconds. Repeat if needed. Persistent odors may mean food is trapped in a part you cannot reach, and a plumber can help.
Is it okay to use the disposer if I have a septic system?
Check your septic system's manual or ask the company that pumps it. Some septic systems handle disposer use fine, while others are damaged by the extra solids. If your system is not designed for it, the solids will fill your tank faster and require more frequent pumping, which costs money.
Can I put coffee grounds down the disposer?
Small amounts of coffee grounds are fine, but do not make it a habit. Coffee grounds do not break down completely and can accumulate in your drain or septic system. Composting them or throwing them in the trash is better.
Why does my disposer leak from underneath?
Leaks usually come from loose connections where the disposer attaches to the sink drain, or from cracks in the unit itself. Turn off the power, place a bucket under the leak, and check if the bolts holding the disposer are tight. If tightening them does not stop the leak, the unit likely has a crack and needs replacement.