The complete list of garbage disposal problems and their solutions

Updated on June 10th, 2019 at 10:41 am

Garbage disposals are indispensible in modern kitchens. However, they are not free of complaints.

Here is a complete list of garbage disposal problems and their solutions;

Problem 1. Garbage disposal humming not working when turned on

If your disposer just hums and not working when turned ON, it is either jammed or doesn’t receive enough electric power for working. This means that the motor is ON but is unable to move the disposer blades.

There are several reasons why this happens;

  1. Presence of accidentally fallen foreign objects like silverware or a lego block
  2. Unground food wastes
  3. Lack of proper electrical connection

Solution: How to fix a garbage disposal that hums?

1. Immediately switch off the power supply

If your disposer is humming don’t wait to enjoy the humming sound; turn it OFF immediately. Failing to do so may fry the motor of the disposal making it permanently useless.

This also makes sure that the disposal is OFF when inspecting it.

2. Do a quick check for foreign objects

It is entirely possible that some items like a spoon or a fork might have fallen into the disposal which is now jamming its grind table. Use a flashlight and inspect through the drain hole, you will be able to see till its bottom. Locate the object causing the problem and remove it using tongs (definitely NOT using your hands)

3. Push the reset button

If you could find nothing that jams the disposer it may be some unground food wastes which are harder to find and remove with tongs. 

It could also be that the electrical connection has tripped, and the motor is not getting enough power to work.

Whatever the case may be it is always easier to press the reset button than getting rid of the possible food wastes. So locate the reset button on the disposal (they are usually on the bottom or the front-facing side.) and press it. This must solve the issue.

4. Manually rotate the blades

If the above two steps don’t solve the problem, then it must be some old food wastes that are causing this problem. This happens if you turned OFF the disposal too early, the remaining food wastes will stick between the grinding plate and the wall jamming the disposal.

Rotating the disposal rotor a few times back and forth will solve this issue.

Luckily disposal manufacturers have foreseen this problem and most disposals come with a hex hole on their bottom side. Find a fitting Allen wrench (1/4″ is the standard hole size), insert it into the hole and turn it in the clockwise and counterclockwise directions. If you are able to freely rotate the blades that means the block is gone. Switch on the disposal and see if it working.

5. Call the experts

If none of the above works probably your disposer is gone. But before you dispose of your disposer give it a last try and call an expert.

Problem 2. Garbage disposal not turning on

If your garbage disposal is not turning on ,then either the disposal motor is damaged or electric power is not reaching it. This can also happen if the overload protector is tripped.

Solution: How to fix a garbage disposal that is not turning on

1. Check whether the overload protector is tripped

If the garbage disposal is overloaded or is heated the overload protector aka reset switch will be tripped. This is to protect the disposer from damages and prevents it from working even if the power is turned on.

When it is tripped it will be dropped down a few millimeters. if that’s the case then it’s going to be an easy fix.

Locate the reset button located under the disposal. Press that button and see if stays in. If not try again after 10 minutes. Once it is pressed up, turn on the disposal and see if it is working.

2. Check the electrical connections

If overload is not the problem then definitely it is an electric problem.

Check if the circuit-beaker has been tripped.

If it is not, then;

Check the wall switch and make sure no wires are loose.

Check the wire connection to the garbage disposal, sometimes this connection can get loose because of vibrations.

3. Call a technician

If you couldn’t solve the problem through the above steps probably the motor is damaged. In this case, it is likely it cannot be repaired but a visit from a local technician is recommended.

Problem 3. Garbage disposal smoking

If you hear a humming sound from your disposal and still keep it ON, you are going to see some smoke from it :). Smoke from a garbage disposal means that either its circuit or its motor is fried.

Solution:

The first step is to disconnect your disposal and keep your hopes low, if the motor is fried you will have to replace the disposer, there are no other options.

But hopefully, it could be that some of the wires connected to the disposal and got burned. So remove the bottom cover of your disposer and see if any wires are burnt. If yes connect them correctly.

If that’s not the case then look for a better disposal, preferrably one with a longer warranty period.

Problem 4. Garbage disposal leaking

A garbage disposal can leak through several places; top portion just below the flange, sides, and bottom

Garbage disposal leaking from the top: Fix

Leaks from the top are usually caused by imperfect sealing of the garbage disposal with the sink drain hole. This could be a problem with sink flange, gasket or losing the putty sealing between the flange and the sink. Over time these items are likely to get damaged/displaced and cause leaking.

This issue can be fixed only by replacing these items.

To do this first detach the garbage disposal from the sink. This can take some time because you will have to disconnect the drainage pipe first. Then disconnect the mounting and finally remove the disposal. Once done replace the sink flange/gasket with new ones, and reinstall. Make sure you use plumbers putty and ensure they are properly sealed.

Garbage disposal leaking from the side: Fix

Leaks from the sides of a garbage disposal are caused by imperfect connections with the drainage pipe or the dishwasher connector.

First check where the leak is coming from, is it the drainage pipe or the diswasher one?

If the leaking is from the dishwasher connection, remove that conection, clean the inside of both the pipe and the connector. Then connect them using the metal clamp, and make sure it is properly tight.

If the problem is with the drainage pipe, it may be because the rubber gasket inside it got damaged. So to fix this leaking you will have to disasseble the drainage pipe, clean its insides, replace the rubber gasket and reconnect them again. Make sure that all connections are tight and properly sealed.

This should stop any leakings from the side of the disposal.

Garbage disposal leaking from bottom

Unfortunately, this doesn’t have a fix. If your disposal is leaking from the bottom it could be due to damages to its internal seals. Trying to fix these seals are not worth the effort.

What you have to do first is to make sure that the leaks are actually from the bottom, not from anywhere above. If confirmed then you need to replace the disposal.

If your disposal is under warranty you are in luck, all manufacturers replace their disposals if found leaking within warranty time. I suggest you buy a Waste King L-8000 because it comes with a 20-year warranty.

Problem 5. Clogged garbage disposal

It is not surprising to find your disposer clogged. Most common reasons for disposal clogging are;

  • Adding too much food wastes at a time
  • Adding food wastes that you shouldn’t put down the disposal. You can check my printable list of such items here.
  • Lack of flushing water: you need to run plenty of water while running the disposal, and also keep it running for a few minutes after the disposal is stopped to make sure that all food wastes are flushed down the drain.

When you turn ON a clogged disposal it will just keep humming and not turning. The steps to clear a clog is very similar to that of our first problem above. Basically what you have to do here is to get the blades free to move.

Solution: Clear the clogged disposal

To unclog a disposal you have to make sure the blades are free to rotate. Most disposals come with a hex hole on their bottom side which is connected directly to the disposal blade. All you have to do is insert a proper sized Allen wrench (1/4″) and rotate it to and fro until you are able to rotate the bladed fully through the full circle.

If your disposal doesn’t have a hex hole then it is going to be more difficult. What you can do is buy a special garbage disposal wrench like this one, and use it to rotate the blades from above. Or you can even use the handle of a broom but using a special wrench is much easier.

Once you are able to freely rotate the blades run some water. If the clog was a minor one the sink will drain normally, in this case just turn the disposal ON and run it for a few minutes.

If the sink is not draining, then fill it to half-full. Then use a sink plunger (it is different from a toilet plunger) and use it till the sink starts draining. And then run the disposal for a few minutes keeping the water running before adding any food wastes.

If none of this work, it’s time to call a plumber.

Problem 6.Sink Not Draining/Sink Draining only when the garbage disposal is ON

Sometimes the sink won’t drain even after hours. Sometimes if you just switch on the disposal the sink will drain without any delays. These are some of the most common problems experienced by garbage disposal owners. The villain here is usually a clog in the pipe. Another reason is; your garbage disposal is clogged.

Solution: Clear the clog

Step 1: Find where the clog is;

The clog can be in the disposal or down in the pipes.

To identify where the clog is; remove the sink trap and keep the water running. Don’t forget to keep a bucket below the sinkhole 🙂 If the sink drains that means the problem is a clog somewhere down the line and not in the disposer.

Step 2: Remove the clog;

If the clog is in the disposer, then unclog it by following these steps.

But if the clog is in the pipes,

In most cases, the clog occurs in the sink trap. If that’s your case the whole problem can be solved by cleaning it, here is a detailed guide on how to clean a sink trap.

If the clog is farther down the drain then things are going to be difficult. You can use a drain snake to try and clear the block.

If you are still not able to clear the clog but the sink drains when the disposer is working then luckily there are some more options to solve this problem.

First, try flushing the drain with near-boiling hot water (lots of water) while keeping the disposer working. The disposer creates a pressure which pulls the water down through the pipeline, and the hot water will possibly melt some part of the clog (clogs are likely to have some grease/oil which will melt with hot water breaking the whole thing.)

If that doesn’t work, you can also try a combination of methods described here. But it is important that you do NOT pour any chemicals down the garbage disposer because they are likely to corrode the equipment.

Problem 7. Garbage disposal backing up into dishwasher

If you have a dishwasher connected with your garbage disposal, sometimes the water from the disposal may end up in the dishwasher.

This is because the dishwasher line is installed incorrectly.

Probably in your case the dishwasher drain doesn’t have a high loop/air gap that is designed to prevent backflow from the disposer. You have to make sure that the high loop is above the sink flood line to prevent any backflow.

You can also use an air gap device. Minnesota recently introduced a new plumbing code making the use of these air gap devices mandatory, making it illegal to connect dishwashers and garbage disposals directly.

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