Garbage disposal with dripping water symbol

How to Change a Garbage Disposal (Step by step Guide!)

Did your garbage disposal just recently start leaking? Mine did and turns out it was time for a new one. The leak was consistent and constant. We had a plumber come out to take a look. The estimate was $650. Are you kidding me? To change a garbage disposal? Seems high in my book!

So to save some money, I did some research and replaced the garbage disposal myself. Saved me about $500 once it was all said and done. And to be honest it was a pretty easy job. All in all it too me about 90 minutes. Well worth it if you ask me.

Let me walk you through the step by step guide to quickly and easily change out your garbage disposal.

How to change a garbage disposal

Leaks under the sink can come from a number of different places. There are a lot of pipes and fittings that could be broken causing a leak. It is important to determine the leak is coming from the disposal before moving forward! If you have determined that the leak is coming from the garbage disposal, it may be time to replace yours. Garbage disposals on average last about 6-10 years. So if yours is older then it is likely time for a new one anyway. If you are unsure if you need a new garbage disposal watch the video below to help you decide.

So you have determined it is in fact a leak coming from your disposal. Lets take a look at the process of replacing the disposal.

Key parts of disposal install

Mounting Assembly

mounting assembly labeled
  • A. Stopper
  • B. Sink flange
  • C. Fiber gasket
  • D. Backup ring
  • E. Mounting ring
  • F. Screws
  • G. Snap ring


  • H. Mounting gasket
  • I. Lower mounting ring
  • J. Dishwasher inlet
  • K. Discharge outlet
  • L. Wrenchette

Tools required for removal

Tools used for garbage disposal replacement
  • Flash light: lighting under most sinks is not great
  • Plumbers putty
  • Flathead screwdriver
  • Phillips head screwdriver
  • Hammer
  • Needle nose plyers
  • Putty knife

Anatomy of sink plumbing

Picture of sink plumbing with all key parts labeled

Step One: Disconnect the power

This is very important to do prior to starting any removal. Messing around with water and active electrical can be very dangerous.

Depending on your garbage disposal this may be as simple as unplugging the system. Some garbage disposals come with a plug and others come hard wired. So if yours has a plug, simply unplug it and you are good to move on.

Pulling electrical plug out from the outlet.

If your system is hard wired then you must shut of the breaker associated with the disposal. Find your electrical box and shut the breaker off that controls the garbage disposal. Make sure you test the disposal switch before proceeding. If you flick the switch and the disposal does not come on, you are good to go.

Shutting the breaker off that is associated with the garbage disposal.

Now that the electrical is taken care of, lets move on to the next step.

Step Two: Remove the dishwasher and discharge drain

Most disposals have two drains connected to them: the dishwasher drain and the discharge drain. The dishwasher drain connects the disposal to the dishwasher. Dirty water from the dishwasher gets cycled through the disposal before draining through the main drain. The main drain connects the disposal to the main plumbing. It is were all the water and waste exits the disposal from. If you do not have a dishwasher you will only have the main drain to worry about.

Dishwasher drain and discharge drain labeled on garbage disposal

Make sure to have a bucket or bowl handy because there is likely some water in the tubes that will drain out once disconnected.

Each drain set up will be a little different. My discharge drain was connected with two flat head screws. Most main drains I have seen all have very similar connections. They use a discharge tube, a flange, and gasket that are all connected to the disposal with two bolts (most of which are flat head). So you will likely just need to unscrew the two screws and pop the drain out.

Removing discharge drain from disposal with flathead screwdriver

The connection from the discharge tube to the rest of the plumbing will very greatly for everyone. So depending on your set up you may not be able to move the discharge tube much. This is alright. You just have to make sure that the tube is loose and free from the disposal.

Discharge tube removed from the disposal

The dishwasher drain likely has a lot more variability with how it is connected to the disposal. For most you will see some type of clamp ring keeping the connection tight. Clamp rings are held tight by either a flat head or Philips head screw. So just use the necessary screwdriver to loosen the clamp ring.

Clamp rings to tighten drains

There was a lot of water in my dishwasher hose so definitely make sure to have that bucket handy. Once the dishwasher connection is free you can set the tube aside and out of the way (you will have a lot more slack in this tube then the discharge drain).

Dishwasher drain removed from the disposal.

Step Three: Remove the old disposal

Before removing the old disposal it is important to note that garbage disposals are pretty heavy. Working under a sink can be awkward and difficult. It can be hard to hold the disposal up once disconnected. You want to avoid this at all costs and prevent any injury. So what you can do is use some other props such as pots, wood, paint cans, etc. Create something sturdy that the old disposal can rest on once disconnected.

Base built up under disposal to hold it up after it is removed.

Each disposal set up is a little different but for the most part they are all very similar. They often have a couple of flanges that are connected to the sink and then a quick connect or mounting ring.

Flange set up under the sink that connects to disposal.

On my set up the disposal had a mounting gasket on top. This is what twisted onto the mounting ring of the sink. There were small rings on the disposals mounting gasket for a screwdriver. If yours is the same, just insert a screwdriver into one of the rings on the mounting ring.

Screwdriver in rings on gasket with arrow representing direction to turn

Once the screw driver was inserted rotate clockwise (to the left) to loosen the connection. Once it is rotated enough the disposal will drop down from the mounting ring. Now that the disposal is off the mount you can set it aside and out of the way.

Disposal removed from mounting set up.
Disposal removed from mounting assembly

As stated before, each disposal set up will be a little different. If yours is not like mine, I recommend referring to the instruction manual for appropriate removal.

Also, if your disposal is hardwired (like mine was) then you cannot put the disposal too far away yet. It is still connected to the electrical. So in the next step we will discuss how to disconnect the electrical cords.

Disposal removed but still hardwired to the house
Electrical still attached to disposal

Step Four: Disconnect electrical

If your device is not hardwired (there is a plug and you already disconnected it, then skip this step). Move directly to step five.

If your device is hardwired lets go over how to disconnect the disposal wiring from the house wiring.

Wires entering the disposal at the bottom

Before starting this step you should make sure double check that the circuit breaker that controls the disposal has been switched to off.

With the breaker off, remove the electrical plate from the disposal. This is held in place by a single Philips head screw. Once the plate is removed you can fish the wires out of the square hole.

Picture of electrical plate on bottom of disposal and electrical plate removed

When the wires are out you will notice there are two white wires and two black wires both attached with a yellow wire nuts (depending on set up they may be attached with electrical tape). There is also a wire attached to a green screw of the disposal, this is your ground wire. The white wires are neutral and the black wires are hot.

Black wires labeled hot and white wires labeled neutral

With the wires accessible you can now unscrew the wire nuts that attached the wires. When the wire nuts are removed (save them for installation) you will notice one of the wires is wrapped around the other.

White wires connected

Untwist the wires so they completely separate. Then loosen the ground wire screw so that the wire can be removed. With the wires completely free you can now pull the electrical wires (ones coming from the house) out the access hole on the bottom of disposal.

Disposal wires and house wires detached and labeled with ground screw labeled

The disposal’s wires will remain in the disposals housing unit. Now you can set the old disposal to the side and make sure you place the electrical wires from the house out of the way in a dry spot.

Step Five: Remove the old mounting pieces

If you are replacing your garbage disposal with the same brand then you can skip this step completely. You will be able to attach the new disposal to the old mounting system under the sink. If so jump to step six.

The mounting system has three screws that need to be loosened. Once these are loosened enough the mounting ring will drop and expose a snap ring.

Mounting screws and snap ring labeled.

Use a screwdriver or needle nose plyers to pry between the snap ring and sink flange. Then push the snap ring down so that it completely pops off. Once this happens the mounting ring, backup ring and fiber gasket will all drop down off the sink flange. The only thing that should be remaining now is the sink flange.

Using screw driver to pop snap ring off.

Next use a hammer to tap the sink flange from the bottom. Do this until it pops up from the sink connection. Once jarred loose you can grab it from the top and set it aside.

With the flange removed you will notice there is likely plumbers putty surrounding the sink hole. You should carefully scrape this and clean it as best you can. I used a putty knife and some alcohol.

Sink before and after in regards to plumbers putty removal.

So now that everything has been removed, lets start installing the new disposal.

Step Six: Insert the new sink flange

First, take about 4 oz of plumbers putty and roll it into a thin rope. Place the putty around the sinks opening. Make sure it is big enough to go completely around the ring.

Plumbers putty around sink flange

Now place the new sink flange in the opening. Press the flange down using your hands as hard as you can. You will notice excess putty will appear and that is ok. Apply slow and firm pressure. Then use a screwdriver or putty knife to remove the excess putty.

Wiping excess putty from around sink hole and flange.

Once this is complete you will have formed a solid seal so no leaking can occur.

Step Seven: Finish mounting flange under the sink

Now it is time to install the mounting assembly to the sink flange. This will happen under the sink and the pieces are mounted in a specific order. This order should be clearly defined in your owners manual. Also this step will vary slightly depending on the brand of disposal you are installing.

Disposal owners manual with mounting set up labeled

First, slip the fiber gasket and metal backup ring (flat side up) over the sink flange. Holding the gasket and backup ring in place, slip the mounting ring over the sink flange so it sits against the backup ring. Make sure these remain tightly pressed and then slide snap ring over flange until it pops into the groove on the flange.

Mounting set up being put together under the sink.

This can be difficult and you may feel like you do not have enough hands. If that is the case you can use a rubber band to hold the gasket, backup and mounting ring up as you place the snap ring in place.

Lastly, you can tighten the three mounting screws until the assembly is seated tightly and evenly against the sink.

Mounting system fully assembled
Snap ring holding everything in place

Now the mounting system is in place so it is time to move on to the disposal.

Step Eight: Pop out the dishwasher plug

If you will not be attaching a dishwasher to the disposal then ignore this and jump to step nine.

Before installing the dishwasher drain, you first have to pop out the plug in the disposal. Place a screwdriver in the dishwasher hole on then disposal. Then lightly tap a hammer on the screwdriver. Do this until you pop out the plug. Then make sure to grab the plug out from inside the disposal.

Stopper popped out of disposal for dishwasher drain

Step Nine: Attach discharge tube to disposal

Now is the best time to attach the discharge tube to the disposal. If you try and do this with the disposal mounted it will be much more difficult.

With most new disposals they will provide a brand new discharge tube. There will also be a metal flange, rubber gasket and two bolts.

Discharge drain materials

Depending on the anatomy of your sinks plumbing you may decide to use the discharge tube provided, or you can use your original one. My set up was slightly different so I used my original discharge tube. I needed the tube to be straight and the one they provided was curved.

To install, slide the metal flange over the discharge tube and then place the rubber gasket into the disposals discharge outlet.

Rubber gasket in discharge tube with metal flange over it

Then place the discharge tube over the discharge outlet and fasten with the two bolts provided.

Discharge tube mounted on disposal

Now that the tube is mounted you can move on to step ten.

Step Ten: Hardwire the disposal

If your disposal has a plug in system then move on to the next step.

If yours is hardwired, it is essential you do it before attaching disposal to sink. It will be much easier and make things more accessible.

First you have to remove the electrical cover plate from the bottom of disposer. It is most often attached with a single screw. Then pull out the black and white wires that are housed in the disposal.

Removing cover plate from electrical box on garbage disposal

Now run the house electrical cables (should be black, white and exposed/ground wires) through the access hole on the bottom of the disposal. Then if they are not already, strip the wires back ~1/2 inch to expose the metal. Connect the two white wires together (neutral), and the two black wires together (hot). To connect them wrap the metal tips around each other and then connect with wire nuts.

Disposal wires wrapped around each other and wire nuts used.

Now you can place the black and white wires back in the disposals housing unit. DO NOT displace the cardboard insulation shield when doing so. This is for protection against leaks.

Lastly take the ground wire and wrap it around the green screw on the disposal. Then tighten the screw.

Grounding disposal by attaching ground wire to ground screw

With all the wires safely placed in the housing unit you can now put the cover back on. Using the screw you just removed, replace the electrical cover plate.

Wires in housing unit and covered

Now that your disposal is hardwired, you are ready to move on.

Step Eleven: Mount the new disposal

Time to mount the disposal to the sink. With this it is important to remember that each set up will be a little different depending on the brand. I HIGHLY RECOMMEND referring to your owners manual if your set up is different then mine.

First you must place the nylon ring over the discharge tube (this will connect the discharge tube to the tee tube). Next, place the discharge tube in the tee tube that connects to the rest of the plumbing. DO not connect the nylon ring yet.

Connecting discharge tube to rest of plumbing

Now grab the disposal and locate the three mounting tabs on the disposal. These tabs should slide over the mounting tracks on the mounting ring. Do not let go of the disposal at this time but move on to step twelve.

Placing tabs of disposal on the track of mounting unit

Step Twelve: Tighten the disposal on the mount

Now that the disposal is mounted on the mounting ring it is time to tighten it. Place a screwdriver in the mounting lug and rotate counterclockwise (to the right). You will hit a hard stop and that means the disposal is fully tight. Disposal can now hang by itself.

Tightening disposal on mounting assembly

Step Thirteen: Tighten main line connections

Now that the disposal is mounted you can tighten up the discharge tube connection to the tee tube. All you have to do is tighten the nylon ring on the threads of the tee tube. Make sure this is tightened fully to prevent any leaks.

Tightening ring on disposal tube

Step Fourteen: Reconnect the dishwasher line

Make sure the hose clamp is still on the hose. Place the end of the hose on the dishwasher inlet of the disposal. It should be a snug fit. Then slide the hose clamp over the part of tube that is connected to the disposal. Then use the appropriate screwdriver to fully tighten the clamp. Does not matter what kind of hose clamp you use, just make sure it is tight and secure.

Step Fifteen: Turn power on and test

Now that everything is connected and the disposal is mounted, it is ready to use. You can plug the disposal in (if yours has a plug). If yours is hardwired, go turn the breaker back on. Now you can test the disposal switch to make sure it is working. Make sure water is running when you test it.

It is a good idea over the next couple months to just occasionally check under the sink. Check all the connections you just made to make sure there are no leaks.


This is a step-by-step guide on how to change out your leaking or damaged garbage disposal.

  • Key parts of disposal
  • Tools required for removal
  • Anatomy of sink plumbing
  • Step One: Disconnect the power
  • Step Two: Remove the dishwasher and main drains
  • Step Three: Remove the old disposal
  • Step Four: Disconnect electrical
  • Step Five: Remove the old mounting pieces
  • Step Six: Insert the new sink flange
  • Step Seven: Finish mounting flange under the sink
  • Step Eight: Pop out the dishwasher plug
  • Step Nine: Attach main drain to disposal
  • Step Ten: Hardwire the disposal
  • Step Eleven: Mount the new disposal
  • Step Twelve: Tighten the disposal on the mount
  • Step Thirteen: Tighten main line connections
  • Step Fourteen: Reconnect the dishwasher line
  • Step Fifteen: Turn power on and test

Hopefully this guide helped you change out your garbage disposal. If so, I would love to hear about it in the comments.

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