Your garbage disposal will make a rattling sound if a hard object gets stuck in its cylindrical canister. It might also hum continuously if the motor bearing is loose or the impeller and flywheel are stuck, for instance by a piece of hard debris. So, what should you do if you notice your garbage disposal making a loud noise?
If your garbage disposal is making noise, turn off the power supply. Then, use a flashlight to inspect the unit, and carefully lift out any stuck objects with kitchen tongs or needle-nose pliers. If the flywheel is jammed, you can typically rotate it from beneath with a hex wrench.
Failing to act when you notice an unusual sound in your garbage disposal may result in further damage to the machine, your sink, or the kitchen plumbing. So, if you hear a noise, don’t ignore it. Let’s take a closer look at the ways to address a loud garbage disposal.
3 causes of loud garbage disposal
Your garbage disposal will make a loud noise if the unit is loose under the sink or a hard object like a spoon or bone has fallen into it. The unit may also vibrate.
The disposal makes a noise if a bearing in the motor is loose. However, the hum from a loose motor bearing should be easy to distinguish from the rattle hard objects make as they get tossed about in the canister.
| Signs of Loud Garbage Disposal | Causes of Loud Garbage Disposal |
|---|---|
| Loud Noise And Unit Vibrates | Jammed Blades Or Stuck Object |
| Unit Makes Loud Noise When Started | Your unit has an auto-reverse designed to dislodge items. Check for stuck object |
| No Stuck Object, Freely Moving Blades And Still Noisy | Loose Bearings or Internal Motor Issues |
1. Jammed Object
The most common — and often overlooked — cause of a garbage disposal unit making a rattling noise is that there’s a jammed object in the canister. Objects that could accidentally get washed down the drain into the disposal unit include toys, bones, broken glass, and plastic objects.
It’s easy to assume that your garbage disposal has blades that cut up food junk, but that’s not actually the case. Rather, there are only impellers at the bottom of the canister. Their job is to fling the food against the sides of the canister and into the shredder ring where the real chopping occurs.
The shredder ring, which is about 2 inches wide, can only work on soft food material. If a hard object finds its way down the shredder ring, it simply gets flung repeatedly against the ring, making that annoying rattling noise.
In this case, the shredder won’t be able to do its job. It probably won’t get damaged, but the impellers may take on a couple of dents. It’s best to turn off the power and carefully remove the object as soon as you can to avoid damaging the unit.
How to Safely Remove an Object From a Garbage Disposal
Before removing any foreign object from your garbage disposal, cut off the power supply to the unit by unplugging it — or by flipping the circuit breaker if it’s hardwired.
As a cautionary measure, never reach into the canister with your hand, as you could get injured by the shredder ring.
Carefully inspect the unit with a flashlight to locate the stuck object. If the object is large — like a spoon or salt shaker — carefully grip it and lift it out with a pair of kitchen tongs or needle-nose pliers.
In the case of objects like bones, which may break down into tiny pieces, start by carefully removing all the pieces you can see. You don’t want small pieces getting stuck in the space between the shredder ring and the motor.
If you find nothing lodged in the unit, it could mean the appliance is failing. Remember, frequent use causes wear on the garbage disposal blades, and they may become dull.
2. Jammed Blades
A loud humming noise from your disposal usually indicates that the blades are jammed. They may have caught onto something that prevents them from rotating any further. In this case, the motor will keep running, but it may only hum since it can’t turn the blades.
To restore operation, turn off the power and insert the offset wrench that came with the disposal into the flywheel turning hole. An Allen hex wrench with a ¼-inch head (on Amazon) can also come in handy.
Alternatively, use the wooden handle of a broom to reach the flywheel through the drain opening. Gently turn the flywheel forward and backward to free it.
Special Hint: One nifty method that I’ve used many times is to put ice cubes down the garburator whilst it’s running, with the tap running. This often works and may prevent you from having to get in there with your hands!
Use a flashlight to locate the stuck objects and pull them out carefully with needle-nose pliers. Once you’ve freed the flywheel, plug the machine back in, but don’t turn on the power just yet. Press the reset button first.
Next, run tap water into the unit and quickly flip the power switch on and off to send a short burst of water to wash down residual debris.
Once you’ve fixed the problem, try to be careful with the foods you send through your garbage disposal. You don’t want sticky or large solid food chunks going into the unit. You should also run water through the unit as it runs to help wash out pieces of food from the unit and down the drain.
3. Loose Pipes or Screws
With time, the pipes and screws in your garbage disposal unit can become loose, causing the system to rattle as it operates. Check your plumbing and the fixture that holds the disposal to the sink flange. All connections should fit snugly, with no signs of rust.
At times, it’s the impeller plate that’s loose. By design, the impellers are meant to spin, but they shouldn’t move back and forth. So, when they move about, it’s usually because the screws holding them in place are loose.
If everything fits firmly in place, the problem could lie with the motor bearings. Garbage disposals are usually sealed units and so it’s unlikely that just the motor can be replaced.
replacing your garbage disposal unit
Since it’s tough and uneconomical to repair your garbage disposal I thought it’d be helpful to give some expert tips before purchasing a new garbage disposal unit:
- It’s not that hard to replace a garbage disposal unit yourself, even if the thought of it might seem daunting. There are loads of great Youtube tutorial videos out there and Garbage Disposal units (on Amazon) are now really cheap.
- Try to purchase the same brand of garbage disposal and make sure the mounting ring is the same style. There’s no need to replace the drain if it’s still in good shape.
- Take pictures of your old units’ set-up before dismantling. Then you’ll have a reference for the re-install. Take the end section of existing plumbing as well as the drain piece that connects to the disposal to the hardware store so you get the right size pieces and seals.
Here’s a decent video tutorial I found that you might find helpful:
tips to make your garbage disposal quieter
If you’ve checked for blockages and unjammed the blades, but your disposal unit is still loud, there are a couple of things you can do to make the unit quieter:
run water whilst using the garbage disposal
Running water will help move food scraps down your plumbing system and will remove some of the strain your unit experiences. It’ll also stop the blades from getting gummed up with food.
Be careful to use cold running water. Hot water may make certain foods expand – such as rice or pasta – actually putting more strain on your system. The one exception is when you’re disposing of grease or fat, where you should use hot water, as cold water can make grease congeal.
use a sink strainer
A sink strainer above your garbage disposal can actually be really effective in blocking some of the noise. A rubber one like this (on Amazon) would do the job.
other related articles
Garbage Disposal Humming Not Working: 5 Steps To Fix
Garbage Disposal Backing Up Into Other Sink: Cause And Fix
Garbage Disposal Reset Button Not Working? Here’s How To Fix It
