Should Dishwasher Be Connected To Garbage Disposal?

Dishwashers and garbage disposals are the two major appliances, especially in modern households.

However, they operate differently and have different kitchen functions. For example, dishwashers clean your dishes, but garbage disposals grind food scraps.

Therefore, it can be confusing whether or not you should connect your dishwashers to garbage disposals.

This article will explain if you should connect your dishwasher to your garbage disposal and how to do it.

Most dishwashers have a built-in food grinder, which can be connected directly to the sewer line. However, if you have a garbage disposal, you may want to connect your dishwasher to it to prevent blockage and save you the time and money you’ll spend on the plumber if you don’t. In addition, doing this helps avoid the issue of clogging.

Does a Dishwasher Have to Be Connected to a Garbage Disposal?

Should Dishwasher Be Connected to Garbage Disposal

You do not have to connect your dishwasher to a garbage disposal, and there are alternatives to draining your dishwasher other than using a garbage disposal.

Apart from that, most dishwashers have built-in garbage disposals, so installing one is unnecessary. 

If you have a garbage disposal in your home and your dishwasher doesn’t have one built-in, you can connect it to the one you have.

Remember a few things if you connect your dishwasher to your garbage disposal. First, ensure you install your dishwasher correctly and secure the connection; then, ensure that your dishwasher and disposal are compatible. 

Most newer dishwashers have an adapter that allows them to connect directly with the garbage disposal; however, older models may not have one or require an adaptor kit that you can purchase at any home improvement store.

Third, to connect it to a dishwasher, ensure a power source is near your disposal. You may need an extension cord or to modify your electrical installation.

Your garbage disposal should have instructions on how it can be connected and what kinds of extension cords are needed. 

However, if you’re not comfortable doing electrical work yourself, hire a professional plumber to ensure everything is connected correctly and in compliance with local codes.

Whether you want your dishwasher connected to a garbage disposal is personal. 

There are some benefits to connecting your dishwasher to garbage disposals, such as less water waste and fewer dishes that need to be pre-rinsed before being placed in the dishwasher.

However, there are drawbacks, such as the potential food scraps and grease build-up in the pipes.

You can choose to connect your dishwasher to the garbage disposal, or you can choose not to. Either way, your dishwasher should still provide excellent service for many years.

In addition, having your dishwasher connected is convenient and helps conserve water and energy

Still, it might not be worth having if it results in more time-consuming pre-rinsing of dishes before you load them into your machine.

You’ll need to decide what works best for you and your family based on your needs and preferences.

If you enjoy having a dishwasher, there’s no reason not to use it at your disposal. The most important thing is to know what works best for your needs and preferences. That is the most important thing.

This information can come in handy for people who have both appliances and want an easy way to determine if they are connecting them correctly, as well as for people who have one or neither appliance and need information on how they should use it.

How Are the Dishwasher And Disposal Connected? 

You connect your dishwasher to the disposal through a drainage hose. The hose is connected to the side of the disposal unit and goes down into the drain.

There is a small hole in the bottom of the dishwasher that allows water to drain out. The dishwasher pumps water through the hose and into the disposal unit.

The disposal unit grinds up food waste and sends it down the drain. Most manufacturers design the units so you can use them separately.

Some garbage disposals have an extra hole that lets you connect them to your sink. First, find a hose that connects them and install it.

Next, you should install the other end of that hose on your dishwasher according to the manufacturer’s instructions. You may also need additional parts to make it work correctly.

Installing a dishwasher and disposal in your kitchen will allow you to quickly and easily clean your dishes.

These units work together so that you can clean all of your dishes thoroughly and without effort.

Of course, you can use each separately if necessary, but using them together is much more convenient because it allows you to put all your dirty dishes in one place.

How to Connect a Dishwasher to a Garbage Disposal Without an Air Gap?

If you want to connect your dishwasher to your garbage disposal without using an air gap, there are other alternatives you can go with.

However, ensure you check your area’s plumbing code before doing so because, in some areas, one is necessary. You can check here for the code on dishwasher installation.

You can use a high loop, a check valve, or a standpipe to replace an air gap. In the table below are the various alternatives you can use.

Now that you know there are alternatives to using an air gap choose an option that suits you and follow the steps listed below to connect your dishwasher to your garbage disposal.

  • Turn off the power to the garbage disposal and dishwasher at the circuit breaker.
  • Place a bucket beneath the dishwasher drain hose where it will connect to the garbage disposal. 
  • The dishwasher’s drain pipe connects it to a waste disposal pipe fitting, and it’s typically sealed, so open it. Connect the disposal to the sink flange, then connect the dishwasher to the garbage disposal.
  • You can connect the drain pipe with high loops, standpipes, or check valves. Then attach the drain pipe as you would to the garbage disposal unit.
  • Use a utility knife to cut through any caulk or sealant that may seal the connection between the dishwasher drain hose and the garbage disposal inlet. 
  • Hand-tighten a 90-degree elbow onto the inlet of the garbage disposal, then attach the dishwasher drain hose to this elbow. 
  • Test leaks by turning the water supply valve to the dishwasher and looking for leaks. If there are no leaks, turn on the water supply valve to the garbage disposal, turn on both appliances, and run hot water into a sink near both appliances for about 30 seconds. 
  • Flush out the system by running a pot of water from the tap on one side to the other without stopping (i.e., from left to right) until all air is out of the line. 
  • Shut off both appliances and remove any temporary plumbing if needed. 
  • Plug in the dishwasher and check for leaks after it has filled with water and turned on. 
  • Cover up exposed pipe connections with tape or sealant, so they don’t leak later on when you’re not looking! 

You have successfully connected your dishwasher to the garbage disposal without an air gap.

Can Dishwasher Drain Directly into Waste Line?

Yes, you can drain your dishwasher directly into the waste line; however, this isn’t advisable.

Doing this could lead to more problems for your dishwasher, like dirty water coming back into your dishwasher. 

Although it isn’t exactly stated in the plumbing code that you can’t drain directly into the waste line, depending on your area, it might become an issue during an inspection.

The drain line of your dishwasher has to be high above 20 feet to ensure that the water does not come back to the dishwasher.

You must ensure that the drain hose is looped high and connected to the waste line.

This arrangement won’t be possible if you want it to drain directly into the waste line, there will be an issue of wastewater back feeding into the dishwasher.

When you connect a drain to a waste line at a point less than 20 inches from the kitchen floor, the drain must have an air-gap device, which you must install above the rim of the sink.

This requirement applies when the drain in question connects to the waste line below this point.

Can Garbage Disposal Cause Dishwasher Not Drain?

Yes, a garbage disposal can cause your dishwasher not to drain. Listed below are some reasons for it:

  • If your garbage disposal becomes clogged with food particles or oil, this may cause a delay in the water’s passage out of the dishwasher, which results in the dishwasher not draining well.
  • Sometimes, the grinders in garbage disposals can break up food particles too finely, causing them to get stuck in the dishwasher’s drain.
  • Filled garbage disposal could also cause your dishwasher not to drain.
  • When installing a new garbage disposal, if you do not do the installation correctly, it will cause the dishwasher not to drain. Check that you remove the knock-out plug; otherwise, the dishwasher won’t drain.
  • A dishwasher needs a certain amount of water pressure to function correctly. If the garbage disposal is draining simultaneously with the dishwasher, it can reduce the water pressure available to the dishwasher, causing it not to drain correctly.

Cleaning garbage disposal is not difficult, and you may be able to do it yourself. However, if you have any problems with your garbage disposal or sink drain line, it’s best to contact a plumber for help.

In addition, a clogged dishwasher drain can lead to water flooding onto your kitchen floor, so you must address any issues quickly.

How Do You Bypass a Dishwasher with a Garbage Disposal? 

You can bypass a dishwasher with a garbage disposal by running a drain line from the disposal to the dishwasher.

That will allow the dishwasher to drain directly into the disposal. In addition, it will allow the water from the sink to go directly into the dishwasher without going through the garbage disposal.

If you run the garbage disposal simultaneously with the dishwasher, you will maximize the effectiveness of both appliances.

In addition, you do not need to be concerned about how dishwashers dispose of waste.

When installing a disposal unit for the first time, you must remove the knock-out plugs within the dishwasher.

You can accomplish this by turning the screwdriver to point inward; it will get the knockouts. Then you take it out of the garbage disposal.

Then put the sink flange and garbage disposal in place. Next, establish a connection between the drain pipe and the drain line located at the base.

Next, to empty the dishwasher, connect the drain hose to the garbage disposal. To secure it in position, you might need to use a hose clamp. Finally, connect the garbage disposal to a working power outlet.

Check that there is no water leaking; therefore, you completed the installation. Now it will break down food into smaller pieces to flush it out more quickly.


In summary, your dishwasher can work well without you having to connect it to garbage disposal, but doing so has an added advantage.

Connecting it to garbage disposal reduces clogging in the dishwasher and makes it last longer, as well as having a clean home. In addition, you can connect it by yourself without the help of a plumber.

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