Garbage disposal maintenance: schedule, lifespan and costs
Updated
Overview
The garbage disposal is a motor under the sink that spins a plate with blunt lugs on it, flinging food scraps against a grinding ring until they're small enough to wash down the drain. It has no blades to sharpen and almost nothing to maintain. What it needs is to be kept clean, so the film of ground food on its walls doesn't grow the bacteria that make a sink smell, and to be fed the right things, since most disposals die of what went down them rather than of age.
Lifespan
A garbage disposal lasts 8 to 15 years. What shortens that is abuse. Grease poured down it coats the chamber and the drain line until the drain clogs. Fibrous scraps like celery and corn husks wrap around the plate. Starches like pasta and rice swell into a paste. Hard things like bones and fruit pits jam it, and a jam that's forced burns out the motor. Running it without water, or running it dry for long, overheats the motor too.
What extends the life is cold water running every time it runs, a weekly clean, and a short list of things that go in the trash instead. The signs a disposal is near the end: a motor that hums and won't turn even after the jam is cleared with the hex key, a reset button that has to be pressed more and more often, water leaking from the bottom of the unit, which means the seal around the motor has failed, and grinding that takes far longer than it used to.
Maintenance schedule
The one scheduled job, which is also the easiest in the kitchen.
| Task | How often |
|---|---|
| Clean the garbage disposal | a quick clean every week, a deeper clean once a month |
Alongside it, a habit: run cold water before, during and for a while after every use, so the ground food is carried all the way down the drain rather than settling in the trap.
Replacement cost
A new garbage disposal costs $150 to $500 installed. The low end is a basic unit with a small motor, and the high end is a quieter, more powerful one with stainless grinding parts that handle more and jam less. Replacement is a common handyman job, and an owner with a wrench and a bucket can do it in an afternoon, since a new unit usually mounts to the existing sink flange.
The repair-or-replace rule: a disposal is cheap enough that most failures are replacements. A jam cleared with the hex key, a tripped reset button, or a leak at the drain connection that tightens up is a fix. A motor that won't turn, a leak from the bottom of the housing, or a cracked body is a new disposal, and if the old one is past the middle of its lifespan, a new one is the better buy than a repair of any size.
Common problems
- A sour smell from the sink: the film of ground food on the chamber walls and under the splash guard. Clean the garbage disposal.
- The disposal hums but won't turn: a jam. Switch off the power, turn the plate with the hex key in the slot on the bottom, and press the reset button.
- The disposal is silent when switched on: the reset button has tripped, or the power is off. Press the reset, then check the switch and the outlet it plugs into.
- The sink drains slowly or backs up: grease and starch coating the drain line below the disposal. A plunger or a drain snake clears it, and the fix is keeping grease out.
- Water leaking under the sink: the drain connection, the dishwasher inlet, or the mounting flange, all of which can be tightened or resealed. A leak from the bottom of the unit itself means the disposal is done.
- Grinding that takes longer than it used to: worn lugs or a worn grinding ring, which is age.
FAQ
How long does a garbage disposal last?
About 8 to 15 years. Cold water, a weekly clean and the right scraps get it to the long end. Grease and jams end it early.
How much does it cost to replace a garbage disposal?
$150 to $500 installed, from a basic unit to a quiet, powerful one with stainless grinding parts.
What should not go in a garbage disposal?
Grease, coffee grounds, fibrous stalks, pasta and rice, bones, fruit pits and anything that isn't food. Grease and starch are what clog the drain line.
How do you unjam a garbage disposal?
Switch off the power, put the hex key that came with it into the slot on the bottom, and work it back and forth until the plate turns freely. Then press the reset button.
Why does my garbage disposal smell?
Food residue on the chamber walls and under the splash guard grows bacteria. Scrub the guard, run ice and salt, and follow with baking soda and vinegar.