Section 3 · Plumbing
Garbage Disposal Problems and Repair Guides
A garbage disposal is a motor under the sink that spins a plate. Two swiveling impellers push food against a toothed ring until it is fine enough to wash down the drain. Jams, a tripped overload button and lost power explain most problems; leaks come from the joints around it.
Start with the symptom
Sink baffle DIY
The rubber flaps in the sink opening keep food and water in the chamber. InSinkErator says to take it out and clean it when the disposal smells, and never to run the unit without it.[5]
Sink flange and mounting assembly DIY
The flange sits in the sink drain hole on plumber’s putty, and the mounting rings below hold the disposal. For a leak here, InSinkErator turns the locking ring fully to the right and checks that the three screws are tight.[5][9] Water under the sink: Sink flange and mounting assembly
Grind plate (shredding disk) DIY
The plate on the chamber floor spins and throws food against the toothed edge around it. A jam stops the plate, and the motor hums without turning.[2] Clear a jam: Grind plate (shredding disk)
Impellers DIY
Two swiveling lugs on the plate push food around the chamber. With the power off, each should move easily when you press it with a spoon handle.[1] Free stuck impellers: Impellers
Discharge elbow DIY
Ground food and water leave through this elbow on the side of the unit. For a leak here, InSinkErator checks that the nut or bolts are tight and that the gasket and elbow are not cracked.[11] Water in the cabinet: Discharge elbow
Drain line and trap DIY
A whirlpool in a sink that won’t drain points to a clogged drain line. InSinkErator pitches the line at least 1/4 inch per foot so no water stands in the disposal.[7][5] Water backs up into the sink: Drain line and trap
Wrench hole (hex socket) DIY
The hole in the center of the bottom, facing the floor. With the power off, a 1/4-inch hex wrench in it turns the plate by hand to free a jam.[2][5] Hums but won’t grind: Wrench hole (hex socket)
How a garbage disposal works
A disposal hangs from the sink drain on a mounting assembly. Food drops through a rubber baffle into the grind chamber. On the chamber floor, a plate spins with two swiveling impellers. They push food around the chamber, and they must turn freely for the unit to work well.[1] The food is ground against the teeth around the edge of the plate.[2] Water carries it out through the discharge elbow on the side and into the trap.
Most units also have a dishwasher inlet, so the dishwasher drains through the disposal. The control is a wall switch, a sink-top air button, or a stopper on batch-feed models.[3]
Two parts are there for the owner. The overload protector is a red button on the bottom of the unit that cuts the motor when something is wrong.[4] The center hole underneath takes a 1/4-inch hex wrench, which turns the plate by hand to free a jam.[2]
Safety basics for garbage disposals
Never put your hand in the grind chamber. InSinkErator's manual says to use long-handled tongs or pliers to remove objects, and to turn the power switch off before you clear a jam.[5]
Disconnect power before you service the unit, and have a qualified electrician check the grounding or fit a new outlet if the plug doesn't fit.[5] Don't put caustic drain cleaners in a disposal; the same manual lists them among things the unit must not take.[5]
Leave the stopper in when the disposal is not running. InSinkErator says this lowers the risk of objects falling in.[5]
Common garbage disposal problems and the first check
Start with the row that matches what you hear or see. Each first check is safe with the switch off.
| Symptom | First check | Guide |
|---|---|---|
| Hums but won't grind | Switch off, then turn the hex wrench in the hole under the unit.[2] | clear a jammed disposal |
| Stopped and went silent | Look for the red button on the bottom; a tripped one sits about a quarter inch low.[4] | — |
| Silent, button is in | Reset the breaker and test the outlet with a lamp. | — |
| Water drips in the cabinet | Wrap paper towels around each joint and drain a full sink.[6] | check the three leak points |
| Water stays in the sink | With the unit running, look for a whirlpool; InSinkErator says one means the drain line is clogged.[7] | a disposal sink that won't drain |
Garbage disposal care and expected life
InSinkErator's manual gives a short routine:[5]
- Turn on the cold water first, then the disposal, and keep the water running for several seconds after grinding.
- Feed food in slowly, and don't fill the chamber with peels all at once.
- Grind small hard items such as small bones, fruit pits and ice now and then; they scour the chamber.
- Don't use hot water while grinding, and never pour grease or fat down the drain.
- To clean it, fill the sink halfway with warm water and 1/4 cup of baking soda, then run the disposal as you pull the stopper. Remove the baffle and wash it by hand or in the dishwasher.
Leaks are worth a regular look. InSinkErator's manual asks owners to inspect the disposer and plumbing fittings for leaks, which can damage property.[5]
Plan for replacement. A 2007 NAHB study put the life of a food waste disposer at about 12 years.[8] Other kitchen and bath fixtures are covered in all plumbing repair guides.
All garbage disposal guides
Troubleshooting
Sources
“Fixing a Garbage Disposal that Won't Grind” · accessed
“Fixing a Jammed Garbage Disposal” · accessed
“Garbage Disposal Has No Power” · accessed
“Resetting a Garbage Disposal” · accessed
“Garbage Disposal Installation Instructions and Care & Use (EZ Connect cord/hardwire adapter, 187004)” · PDF · pp. 16-17 (safety, operating, do and don't, cleaning) · accessed
“Leak Underneath: Existing Garbage Disposal” · accessed
“Fixing a Clogged Garbage Disposal” · accessed
“Study of Life Expectancy of Home Components” · PDF · Table 1, p. 10 (Disposers, Food Waste) · accessed
“Garbage Disposal Leaking at the Discharge” · accessed
How this page was made
This page was drafted with AI assistance from the manufacturer and safety sources listed above, then checked against those sources in an AI-assisted review. No licensed technician reviewed it. Last reviewed . Our methodology