How to Fix a Leaky Garbage Disposal

Last Updated:  November 4, 2020

how to fix a leaking garbage disposalLeaking plumbing fixtures are a very big problem. At a minimum, a leak will run up your water bill and also promote the growth of mold and mildew.

Because of what garbage disposals do, a leaking garbage disposal is worse than most leaks. It’s potentially a serious health hazard.

So if you open the cabinet where your garbage disposal unit resides and find that the floor of the cabinet is wet, the first thing you need to do is find the source of the water. There are several different potential points of failure. Each requires a different remedy.

Safety First

Check Latest PriceBefore you get started, remember that water and electricity are a bad combination, so bad they are potentially deadly. So your very first step should be unplugging the garbage disposal.

You may want to take some additional steps, such as cutting off the electricity at the fuse box. If you have a rubber mat, you might want to put that down to help insulate yourself against potential shocks.

Whatever you do, never ever put your hand in a garbage disposal without disconnecting it first. If it gets turned on while your hand is in it, you could be maimed for life.

This is especially true if it is your dominant hand. Since people tend to work primarily with their dominant hand, it is likely to be your dominant hand.

You may want to gather a few things together to help you deal with this problem. For starters, a flashlight and small hand mirror may help you see what you need to see.

Then get a small bowl, fill it with water and add some food dye. Colored water is a very useful tool for diagnosing the exact source of a leak in your kitchen.

How To Find The Leak in Garbage Disposal?

In order to find the leak, you first need to dry everything off. Sop up any standing water in the bottom of the cabinet, then dry off the garbage disposal and all other surfaces within the cabinet in question.

You can’t figure out where the leak is coming from if things are already wet. It all has to be dried off first in order to help you pinpoint the source of the leak.

Then put a stopper in the disposal side of the sink. This is where the colored water comes in. You pour your food dye infused water into the sink, then check beneath the sink for dripping water.

It’s a good idea to have a dry white rag handy. Colored water plus a white rag can be a powerful combination for locating a leak.

Wiping surfaces beneath the sink with the rag will be a quick and reliable means to find the leak. If you wipe and the rag comes away sporting the same color as the food dye in your test water, you can be confident you’ve found the leak.

If the sink leaks while it is stoppered, it is usually leaking from the flange. This is the part around the drain opening that connects the sink to the disposal or other plumbing.

This is generally good news because the flange is probably the least bad place to find a leak beneath the sink. In many cases, it can be readily fixed with some inexpensive plumber’s putty.

There are two likely causes of a leaky flange:

Over time, the plumber’s putty can get dried out and eventually simply fail. This is probably the most common cause of a leaky flange.

Additionally, if the disposal gets smacked hard enough, that can break the seal. Once broken, the only way it will seal properly again is if you remove the old putty and replace it with new putty.

Plumber’s putty is really cheap and readily available at local hardware stores. It’s also easy to install it. You just roll it between your hands to create a long rope of the right length, then form a circle all the way around the flange.

Just follow the instructions on the container. Probably the hardest part is just making sure you don’t use the sink again until it is fully dry. That seems to be where a lot of do-it-yourself jobs go wrong. Someone forgot to leave the sink alone, got the sealant wet and compromised it.

However, some flanges do not use plumber’s putty at all. Some flanges are simply tightened down with a screwdriver.

When this type of flange develops a leak, the only fix is replacing it. Doing so is a big job and not recommended for the Do-It-Yourselfer.

It involves detaching the disposal, removing the damaged flange and replacing it with a new one. Then you have to reassemble everything.

Your Garbage Disposal Doesn’t Leak While Stoppered

If it isn’t the flange, then testing for leaks with a stopper in the sink probably won’t show anything. If you don’t find a leak while testing it with it stoppered, the next step is to repeat this process without the stopper.

So, remove the stopper and pour some colored water into the sink again. Take a second look beneath the sink to see if there are any drips. Wipe with a white rag to make sure the drip you are seeing is actually the dyed water you poured down the sink and not a leak from some other source.

There are generally two drain line connections coming to the disposal. One goes to a dishwasher and the other to the sewer. If you don’t have a dishwasher, then there will only be one connection to the sewer.

Some connections have a metal clamp. You may be able to just tighten the metal clamp.

Others have a combination of screws and a rubber gasket. You may be able to resolve the issue by replacing the gasket and tightening the screws.

The last place you may find the leak is the bottom of the disposal. This is a big problem and generally means you need to replace the disposal.

Disposals have a number of different internal seals. If one has failed, the others are probably also not in good shape. If they haven’t failed yet, they may soon.

While it is possible to take a disposal apart, locate the damaged seal(s) and replace one or more seals with replacement parts from the original manufacturer, it’s not a best practice. It’s probably not that much cheaper than simply getting a new disposal. Meanwhile, it involves a whole lot of time and effort.

On top of that, if you don’t get it put back together properly, it may not ever work right again. Plus, if you only replace one seal, that may not be the only one leaking, or another one may soon develop a problem and start leaking anew.

In other words, taking it apart to try find and replace a deteriorated seal can mean that you are simply investing time, money and effort in dragging out the pain rather than actually fixing the problem. So the recommended best practice is to simply replace the disposal if the leak is coming from the bottom of the unit, thereby indicating that the problem is a damaged seal within the unit.

But make sure it really is leaking from the bottom and not dripping down to the bottom from someplace higher up. A leaking flange or leaking connection are both generally easier and cheaper to fix than this and water can drip down to the bottom of the disposal from a leak that is actually somewhere higher up.

So if you find water on the bottom of the disposal, run your leak check a second time to verify the source of the leak. Before you start shopping for a new disposal, be sure it really is coming from the bottom of the disposal.

Before You Start Repairs

If you aren’t a professional plumber or otherwise do this kind of work regularly, you may get tripped up by some things that a plumber does automatically without really thinking about it. Because they don’t really think about it, they may not explicitly cover it in instructions or YouTube videos on the topic.

Some of that has to do with realizing that plumbing work can be messy. Some of it has to do with safety. This goes double with doing disposal work because disposals use both water and electricity.


The odds are good that water is going to come out when you start disconnecting things. This water is likely to be nasty stuff.

Make sure the sink is empty and dry. You will want to put a bucket beneath the disposal before you fiddle with anything.

You will want to have some rags or old towels handy to clean up water. No matter how careful you are, plumbing work always involves dealing with some water.

Be able to wipe it up promptly if only for safety reasons. Leaving puddles of water lying around while you work is a good way to slip, fall and get hurt.

This can lead to serious injury requiring medical attention. Running up medical bills while your DIY is not a cost-effective strategy. It’s part of why some people just go ahead and call a professional and let them handle it.


This was already said above, but let’s say it again: Unplug the disposal before you were doing anything. You don’t want to be shocked and you don’t want the blades to begin spinning while you are working on the unit.

Both of these can lead to very serious injuries. It cannot be overstated how serious this can be. So stop and take some precautions.

General Prep

You will want to gather together anything you expect to need during the process, such as work gloves, tools, plumber’s putty, and a rubber mat or cheap bathroom carpet to lay on while working. A rubber mat can help ground you and help mitigate the risk of being shocked.

As stated previously, a small hand mirror and flashlight can come in handy for helping you see into dark corners beneath the sink. They can also come in handy for looking at the bottom of the disposal.

Find Rich Media Instructions

If you need more help than you feel you are getting from just written instructions, you can find instructions on the internet with rich media, such as illustrations, photos and even videos. Here are a couple of videos to get you started:

Easy fixes for garbage disposal leaks: This video goes over some of the fixes talked about here, such as tightening loose connections or replacing the plumber’s putty around the flange.

How to replace a disposal: This video by home depot quickly goes over the process of removing your old disposal and installing a new one. The first minute and a half or so talks about options available in new models. It will start where the actual instructions begin in the video. You can go back to the beginning if you are interested in seeing that portion of it.

Clean Up

If you have had a leak for a while beneath your sink, it’s probably been damp for some time. At a minimum, you want to get it thoroughly cleaned up and dried out. But you may want to do more than that, depending upon how wet it got, how long it stayed wet and other factors.

If you or anyone in the family has health issues, this may be one of the most important steps in the entire process. Even when it is just water, chronic moisture can promote the growth of mold and mildew.

However, if it is water from a disposal, it may be more than just water. Because you put food waste down the disposal, it may be nutrient-enriched water that will more strongly promote the growth of things you don’t want growing anywhere in your house. You can think of it as fertilizer for mold and mildew.

Worse, it may even contain germs. You may be promoting a source of infection in the house.

If that sounds crazy, you could read up on Legionnaire’s Disease. It was discovered in 1976 and was named after the first known outbreak of Legionella pneumophila which occurred at an American Legion convention in Philadelphia.

It is usually not spread from person to person. Instead, it almost always comes from the plumbing system of a building.

While it is most strongly associated with large buildings, such as hotels, that doesn’t mean it can’t grow somewhere in a private home. Legionnaire’s Disease is a serious condition that can be deadly.

So sop up the worst of the water, then put down some rags to soak everything up. Fold the rags flat to maximize contact with the surface they are laying upon, then pile something heavy on top to really force any remaining moisture into the rags.

Ideally, you should not be using anything that can spread a health issue, such as heavy books made of paper. Consider using a brick or other heavy object that won’t become a new source of health issues.

If you have a fan or blow dryer that you don’t mind tossing out afterwards, you can also direct air current at the damp surface to dry it out. You probably don’t want to rent a blower, especially if you have health issues. They are often covered in dust and of questionable cleanliness.

If the cabinet really took it hard, consider simply replacing the cabinet, especially if it is an inexpensive particle board model. It’s pretty much guaranteed to be cheaper to replace the cabinet than it would be to develop some mysterious and chronic health problem that doctors cannot readily identify.

Health problems tend to be a double whammy to the budget. They simultaneously impair your ability to do paid work while also driving up your medical expenses. Anything you can do to prevent such an outcome is going to be cheaper than living that way, even before you consider the hit your quality of life will take.

If The Leak in The Disposal

If the leak is coming from the bottom, the recommended fix is simply replacing the disposal. It’s best to try to look on the bright side and think of this as an opportunity to get a new best disposal.

Disposals typically last several years, so if yours is falling apart, it is probably several years old. If you haven’t shopped for a garbage disposal in a while, you may be pleasantly surprised at your options.

Some Best Practices For Picking A New Disposal

Think about what you liked about your old disposal and also what you disliked. Maybe take a few minutes to write down some of its good points and bad points.

If it was too noisy, the good news is that newer models tend to be quieter than older models. There are new ways to minimize vibrations on the drain connection. Vibrations in this area are a common cause of excess noise when running a disposal.

Do think about whether you want a continuous feed or batch feed model. Continuous feed models are the most common type of disposal, so you may be inclined to buy one out of habit simply because it is familiar.

But let’s talk a bit about batch feed disposals and some of their good points:

They are quieter in part because they only work when stoppered. This helps mitigate noise coming out of the hopper as it runs. If you have a new baby at home or some other reason to be concerned about noise levels, you might want to consider getting a batch feed model for that reason alone.

The fact that they cannot be turned on until the stopper is in place can be a very big deal for some families. It prevents small children, special needs family members and the elderly from doing something really dangerous, such as reaching into the disposal and turning it on, or even reaching into the disposal while it is on.

If you are concerned about the environment, you may want to consider a batch feed model simply because it uses less water than a continuous feed model. This makes it arguably the environmentally-friendly choice.

There are some downsides. It may be tempting to wait until it is full before running it. This can attract insects, grow germs and cause the kitchen to smell. However, it is easily remedied by developing good habits.

Continuous feed models don’t always automatically come with a plug. This can be an extra expense and also an extra step in the installation process.

Although batch feed models tend to be a little pricier, that’s in part because they always include an electrical plug. If that detail helps you install it yourself, then it may also save you the cost of professional installation.

That fact can help you decide that a batch feed model isn’t really any more expensive than a continuous feed model. Or, at least, it may help you decide that minor differences in cost aren’t terribly important because this is an apples-to-oranges comparison in some respects.

Of course, you can buy a continuous feed model. There is nothing wrong with preferring that. But if you are just buying one out of habit without even considering a batch feed model, you may be doing yourself a disservice.

We hope this was helpful to you. If it was the disposal, then happy shopping!