Garbage Disposal Not Working: Causes and Fixes

A garbage disposal that has stopped working is usually one of three things: it has no power, it is jammed, or the motor has burned out. The first two are homeowner fixes that take about ten minutes with a hex wrench and a flashlight. The third is not repairable, and the unit needs replacing.

The fastest way to tell them apart is to listen. Silence when you flip the switch points to power. A hum with no grinding points to a jam. A grinding noise with water pooling in the cabinet below points to a leaking or failed unit. Below is what to do in each case, and the point at which you should stop and call a plumber instead.

Why a Garbage Disposal Stops Working

Five problems account for nearly every one of these calls. They are listed here in the order you should check them, which is also the order of how common they are.

It has lost power, or tripped its own protector

The overload protector has tripped

Every disposal is designed with a thermal overload switch as standard, usually a small red reset button on the underside of the unit. It trips when the motor overheats, most often after a jam or after grinding something dense. This is the most common cause of a disposal that does nothing at all, and it is the easiest to fix.

Something is jammed in the grinding chamber

A hum with no grinding almost always means the flywheel is stuck. Common culprits: a bottle cap, a bit of glass, a bone, a fruit pit, a twist tie, or fibrous scraps like celery or corn husks wound around the impellers. Worth knowing before you look: a disposal has no blades. It grinds with blunt impellers that fling waste against a stationary ring, so an object that stops it is lodged rather than caught on an edge, and dislodging it is usually a matter of turning the flywheel rather than cutting anything free. The motor is drawing current and going nowhere, which is why leaving it humming is the one thing you must not do.

The unit has lost power at the outlet or the breaker

Disposals are usually on a switched outlet under the sink or hardwired to a dedicated circuit. A tripped breaker, a blown fuse in an older panel, a GFCI outlet that needs resetting, or a plug that is no longer properly plugged in after someone stored cleaning supplies under the sink will all leave you with a dead switch and a perfectly good disposal.

The wall switch or the unit's wiring has failed

Less common, but switches wear out. If the disposal has power at the outlet and the reset button is in, and it still does nothing, the switch or the internal wiring is the suspect.

The motor has burned out

Disposals that have been run repeatedly while jammed, or that are simply old, eventually fail outright. Signs: a burning smell, a continuous humming sound, a reset button that trips again within seconds of being pushed, or no response at all after everything else checks out. Nothing you can do at the sink will resolve this one.

The unit is leaking

Water under the sink changes the priority. A leak at the sink flange can be resealed, and a leak at the dishwasher inlet or the discharge tube is usually a gasket or a connection. A leak from the bottom seam of the housing means the internal seal has failed, and that unit is finished.

What to Check First

1. Is it humming or silent? Humming means jam. Silent means power. This one question saves you most of the diagnostic work.
2. Press the reset button. It is a small red button on the bottom of the unit. Push it firmly until it clicks and stays in.
3. Check the outlet and the breaker. Confirm the plug under the sink is seated, then check your panel for a tripped breaker and any GFCI outlet in the kitchen that may need resetting.
4. Look inside the chamber with a flashlight. Do not put your hand in the disposal, ever, even with the power off. Use tongs or needle-nose pliers to pull out any objects you can see.
5. Look for water in the cabinet. If the base of the unit is wet, stop troubleshooting the motor and deal with the leak. Water and an energized appliance in the same cabinet is the one situation where you stop and call for assistance rather than continue.

Step-by-Step: Freeing a Jammed Disposal

Tools: the 1/4-inch hex wrench that came with the unit, also sold as an Allen wrench or hex key and often still taped to the side of the housing, a flashlight, and tongs or needle-nose pliers.

1. Cut the power. This is the one precaution that matters most. Unplug the disposal under the sink, or switch off its breaker if it is hardwired. Turning the wall switch off is not enough. The wall switch can be flipped back on by anyone walking past.
2. Find the hex port. It is the small hole in the center of the bottom of the unit. Insert the hex wrench fully so you can turn the flywheel manually.
3. Work the flywheel loose. Turn the wrench firmly in both directions until it is spinning freely. You will feel resistance and then the jam dislodge. On a stubborn jam, hold steady pressure in one direction for about 30 seconds rather than jerking it back and forth.
4. Remove the debris. Shine a light into the chamber and pull out whatever caused the jam with tongs. Still no hands in the chamber, even now.
5. Press the reset button on the underside of the unit. It should click and stay in.
6. Restore power and test. Run cold water first, then switch the disposal on for a few seconds. If it grinds normally, you are done.

One of these precautions matters more than the rest: never let the disposal sit and hum. Current stalls in the motor windings, and more than a few seconds of that can burn out a motor that was otherwise fine.

When to Call a Plumber

Stop and call a professional if any of these apply:

• Water is leaking from the body of the unit. A failed housing seal cannot be repaired.
• The reset button trips again immediately after you have cleared the jam. That is an electrical fault or a failing motor.
• There is a burning smell or the unit is hot to the touch.
• The sink drains slowly even with the disposal working. The problem is downstream in the drain line, not in the disposal.
• The wiring, the switch or any internal components need work. Hardwired disposals sit on a dedicated circuit, and that is licensed electrical work.
• The unit is under warranty. Opening it yourself usually voids it.

Synergy3 Home Solutions has handled kitchen plumbing across Philadelphia and New Jersey since 2006, and a stuck or failed disposal is a same-visit job in most cases. Our Garbage Disposal Repair team can tell you in a few minutes whether the unit is worth saving or whether you are better off replacing it.

Safety and What Not to Try

Several of these repairs are easy, but only with the power off. Switch off the disposal at the wall and, for anything beyond pressing the reset button, at the breaker as well. Never put your hand into the chamber, even with the power off - use tongs or pliers to remove whatever is in there, and a flashlight to look before you reach. If the unit hums, do not keep the switch on while it does: that is the motor stalled against a jam, and holding it there burns out the windings within seconds.

A few related points worth attention. Water under the sink after a jam usually means a loosened connection at the dishwasher inlet or the drain elbow rather than a failed unit. A disposal that trips the breaker repeatedly has an electrical fault and needs a professional. And if the same jam happens several times in a month, the cause is what is going in rather than the machine - follow the maintenance tips below and the issue usually disappears.

Maintenance Tips to Keep It from Happening Again

• Run cold water before, during and for about 20 seconds after every use. Cold water keeps grease solid so it gets ground and flushed instead of coating the pipe.
• Feed scraps in gradually rather than filling the chamber and switching it on.
• Keep out the things that cause most jams: bones, fruit pits, coffee grounds, eggshells, pasta and rice, potato peels, celery, corn husks and onion skins.
• Never pour grease down the drain, disposal or not.
• Grind a tray of ice cubes every few weeks to knock buildup off the impellers. Regular use of cold water is what prevents most of these failures in the first place.
• Check under the sink twice a year for the early signs of a seal leak, which is a slow drip long before it is a puddle and long before it becomes water damage to the cabinet.

Get Your Disposal Working Again

If the reset button and the hex wrench have not solved it, Get in touch with Synergy3 Home Solutions. We are family-run out of Philadelphia, with 20 years in the trade, a 4.9-star rating, and 500+ Google reviews. Our hours are Monday to Friday 7:00 am to 7:00 pm and Saturday 7:00 am to 3:00 pm during peak season, with same-day service available on most calls.