How to Install a Garbage Disposal in 7 Easy Steps

by Paul

If you are worried about how to install a garbage disposal, let me tell you there’s nothing to worry. I’ve seen many people freak out about installing a new one or changing their old garbage disposal. Following the step by step guidelines, one can very easily install or replace the garbage disposal.

If you already have a garbage disposal in your home and you want to change it, you need to know first how to remove a garbage disposal. After you finish removing your garbage disposal, you can go for the installation process. You can see more how to remove a garbage disposal instruction here in details.

No matter what disposal you’ve bought the installation process is pretty similar for most of the disposals. There may be some small tricks differ depending on different brands. So you just need to know those tricks and believe that you can do the task without any trouble.

Before going to the installation part, please make sure the electric connections are turned off.

Check our guide on our favorite garbage disposals to know which fits your needs.

How to Install a Garbage Disposal in 7 Steps

Step 1: Removing All the Drain Pipes

Before going for an installation, you need to check if you have enough space under your kitchen sink to place the garbage disposal. Then you need to remove the current pieces of drain pipes and the existing drain openings. Also, clean the old plumbers putty from your kitchen sink opening. 

Step 2: Use Some Plumbers Putty to Place the Mounting Bracket

Roll half inches of plumber’s putty in your hand and put it on the opening of the sink. Now set the new sink flange on your sink opening with the plumber’s putty. Put some weight on the above of the sink opening to make sure this sink flange keeps in place when you join the mounting.

For solving general plumbing issues, we also made a more detailed instruction article on it.

Step 3: Attach the Drain Flange and Other Rings

Now you need to attach the Fiber gasket, the backup flange, and the mounting flange one by one. Install the gasket and the upper and lower rings from the bottom of the sink. Tighten the screws and make sure all the three screws are firmly seated on the place. Do not over tighten. Clean the extra putty from your sink opening, and you are good to go for the mounting.

Step 4: Wire Your New Garbage Disposal

Before going for this part just make sure any electric connection is off. To wire your garbage disposal and give it an electric connection you need to open the bottom part of the disposal. You can use wire nuts to make the connection. Just match the color and connect the electric wires. After finishing the wiring just put back the bottom cover again to the disposal unit.

Step 5: Mount the Garbage Disposal

Now you need to hang the disposal depending on the manufacturer’s direction. InSinkErator uses the mounting rings. You can hang the disposal on the mounting bracket, and after finishing all the installation of pipelines, you can lock it with the special wrench provided by them. Waste King has both 3 bolt mounting and EZ-Mounting System. You will get the instruction to mount the system on their manual.

InSinkErator to InSinkErator:

If you are replacing your InSinkErator garbage disposal with a new one, then the installation will be super easy. In that case, you don’t need to work with the mounting. If the mounting bracket and other rings are good to go, you can just twist off the old disposal from your sink and twist on the new one. It’s that easy because of the uniform mounting structure. Just remember, before doing that you need to check the mounting if it’s in good condition.

Step 6: Insert the Discharge Tube & Install the Drain Pipes

You need to put the discharge tube into the coupler. Use the included washer or gasket and connect the discharge opening on the side of the disposal unit. For InSinkErator, you can rotate and align the discharge tube with your drain trap. As all the installations are done now, it’s time to reinstall your drain pipes.

Step 7: Lock the Mounting of InSinkErator

If you are installing an InSinkErator, this is when you need to lock the disposal with your mounting.

After you install the drain pipes and lock your disposer properly to the sink, put the electric connections on and check if your disposal is working.

Also, check if any connection leaks. If you are still in confusion about how to install a garbage disposal, the following video will give you best idea to install your garbage disposal. If this is the first time you are doing an installation, just make sure you read all the instructions carefully and do not hurry.

Follow the manual carefully. Only use the tools as instructed. And last but not the least, make sure your electric connections are off before you go to start the removal and installation process.