How to Install a Dishwasher in existing cabinets: Easy Steps

Buying new appliances is always exciting! They’re shiny and have that ‘new appliance’ smell.

Yet, installing them can be a whole other story, particularly if they require several connections like a dishwasher. That said, some outlets will send an installation team at no extra charge. Sometimes, they’ll even haul away the old one as well. Dishwashers are often installed under or near the sink.

However, that isn’t always the case, especially if you buy it from an online retailer or a local improvement center. Many might offer an installation team to come and get everything done for you, but it comes with a hefty fee. The first step is to install the water supply and drain (read on if you already have this):

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Though, why pay good money for something you can do yourself. Just follow our guide on how to install a dishwasher. We’ll tell you everything you need to know to get your dishwasher up and running.

How to Install a Dishwasher in 10 Easy Steps

Connecting your brand-new dishwasher is easier than you might think. Let’s get started.

Step 1: Gather Your Supplies

Here’s a list of everything you need to install a dishwasher:

  • Your brand-new dishwasher
  • Dishwasher connector kit
  • Electric appliance cord
  • Pipe joint compound
  • Wire connectors
  • Screwdrivers
  • Drill and spade bit
  • Adjustable wrench or channel-lock pliers

Step 2: Understand Your Connections

Dishwashers rely on three main connections to do their job. Before removing the old dishwasher and putting in the new one, you have to turn off the power and water supply line that feeds into the dishwasher.

Take a look.

Water Supply

Connecting the water supply is as easy as attaching the supply tube on the dishwasher’s inlet to the shut-off valve on your home’s hot-water supply pipe. To attach these two ends, you need a 90-degree elbow fitting, also known as a dishwasher 90, that usually comes with the dishwasher connection kit.

Drain Hose

The drain hose goes into the drain trap underneath your sink. You’ll find the exact technique in your user manual, but the general intention for this hose is to prevent the dirty wastewater from flowing back into the dishwasher

Power Connection

This might seem a bit overwhelming, especially if you don’t have electrical experience. Yet, it’s easy if you know what to do.

First off, dishwashers are generally ‘hard-wired’ with a non-metallic (NM) circuit cable, sometimes called a ‘Romex.’ This cable feeds right into the dishwasher’s wire connection box. The more common option is to just have an appliance cord that you plug into the wall outlet.

Starting in 2020, the NEC safety code specifies that dishwashers have GFCI protection. This safety regulation makes it easier to simply disconnect the dishwasher for any future maintenance and servicing.

Step 3: Attach the Electric Cord

All connections we mentioned above are found on the access panel found on the bottom of the dishwasher. Some people prefer to crouch down or lie on the floor to put everything in place.

The easier alternative is to flip the dishwasher on its back, remove the access panel, then make the connections using twist-on wire connectors.

These are the basic wire connections:

  • Green wire from the dishwasher to the green grounding screw
  • White neutral wire to dishwasher white lead wire
  • Black hot wire to dishwasher black lead wire

Connecting the wiring should be done with care, so you need to make sure that you have a dedicated 60Hz circuit with a 20-amp breaker and make sure that the ground wire is properly installed. 

Step 4: Hook Up the Water Supply

This is where the 90-degree elbow we talked about above comes into play. First, find the water inlet fitting on the valve. Apply pipe joint compound to the fitting, then twist onto the solenoid valve.

Start by tightening the valve by hand. Then, for added security, give it an extra turn with an adjustable wrench or channel-lock pliers.

Step 5: Connect the Water Supply Line

In addition to the dishwasher 90, the connector kit also contains a braided steel water supply tube. Attach the coupling nut of this tube onto the dishwasher 90 fitting. Tighten with the adjustable wrench or pliers.

You won’t need any pipe joint compound because this is a compression fitting. However, you have to work carefully to avoid over-tightening the nut and risk stripping the threads.

Step 6: Position Your Dishwasher

Now, it’s time to slide the dishwasher into place underneath the kitchen counter. Make sure you slip the water supply tube, drain hose, and power cord through the holes located in the cabinet sidewall.

If you need to raise the dishwasher, use the adjustable legs that come with the appliance. Then, after lining it up with the opening, push it into place.

Step 7: Anchor the Dishwasher in Place

Once the dishwasher’s in place, you can anchor it in place with fasteners. Prop open the dishwasher door to gain access to the mounting brackets.

Next, position the brackets correctly to the cabinet frame underneath the rim of the counter. Finally, fasten the brackets using the screws provided.

Adding rubber feet can be a great idea as it protects the floor and dishwasher.

Step 8: Hook Up the Water Supply Tube

Find the water supply shut-off valve underneath the sink, and attach it to the dishwasher’s water supply tube. Carefully, turn on the valve and keep an eye out for leaks from the valve.

Also, check for leaks on the other end of the tube at the dishwasher 90 fitting as well. If you notice any leaks, give the fittings another turn with your pliers or wrench.

Step 9: Attach the Drain Hose to the sink or install a dishwasher not next to sink

The drain hose should come already attached to the back of the dishwasher. If it’s not, you can easily connect it using a hose clamp.

The next step is connecting the hose to the kitchen drain pipes, which can be done in two ways: direct and disposal drains. The former goes straight into the kitchen drain pipe. The latter, however, passes by the disposal drain first before draining into the kitchen drain pipe.

In both cases, you’ll need a ‘riser loop’ to ensure that wastewater runs away from the dishwasher and into the pipes without siphoning back.

Make sure you read the user manual to figure out which configuration for the drain hose applies to your dishwasher. The placement should also be in compliance with local safety code requirements.

Below we also explain how to connect the dishwasher to your garbage disposal.

If there is no sink nearby, you will have to install a new PVC drain. We have outlined how you can glue PVC here. You will have to connect this drain to another drain in your house. Make sure that you use a drain that uses grey water as this is used for dishwashers (check your local code to confirm this!). It can be quite difficult to install this in a house if this drain is quite far away. You might have to consult with a plumber to find a solution. In some instances, you can connect the drain to the drain of the washing machine.

Step 10: Test Out Your New Cafe Dishwasher

The final step is to run the dishwasher through a full cycle. Make sure the dishwasher is taking in fresh, clean water. During the rinse cycle, take a look at the drain hose and make sure none of the connections are leaking.

Bonus Step: How to Connect Dishwasher Drain Hose to Garbage Disposal

If you have a garbage disposal, you can sometimes connect the drain of the dishwasher to it. In this way, you don’t have to open up your drains so it is easier to install your dishwasher.

In most cases, an air gap is needed if the drain is 18 inches away from the floor or less. However, if the dishwasher’s location is too far, you will need to make a new outlet that directly connects to your house’s disposed water system. 

This is a safety device that maintains the pressure required that prevents the dirty water from being siphoned into the clean dishwasher. A gradual bend in the drain hose will ensure better drainage when you use your dishwasher. 

If the drain hole is higher, you can follow another method called the high loop. In this case, you bend the drain hose to be higher than the water level in your dishwasher, and this will prevent the backflow. 

Before you start connecting the drain hose, make sure that you have turned off the water and unplugged the garbage disposal. Of course, if the garbage disposal is nearby, the installation process will be a lot easier. Here are the tools you’ll need. 

Tools

  • 7/8-inch drain hose
  • Clamps
  • Screwdrivers

Using Air Gap and Garbage Disposal

This is probably the most common and easiest method. First, you need to trim the drain hose, so it’s long enough to reach the gap. Then, connect them using a clamp

After that, attach the 7/8-inch hose to the gap and the disposal, and make sure you’re using clamps so both ends are secured. The hose should be straight, so it doesn’t restrict proper drainage.

Using High Loop Method

The high loop method isn’t allowed in some communities, so you need to make sure that the local building codes allow it. Also, you’ll need an extra drain hose for this method to work, so you’ll have to pull most of it out. 

Place the hose high enough to prevent the dirty water from the garbage disposal from back flowing into the appliance. Finally, use a large pipe clamp to secure the hose to the wall. 

Wrap Up

Learning the ins and outs of how to install a dishwasher is easy. After following our easy 10-step guide, you’ll have a fully functioning dishwasher in no time.

Now, go enjoy some much-deserved downtime. You’ve earned it!