A Complete Guide on How to Install a Dishwasher


When it comes to renovating a kitchen, the one question which may cross your mind is how to install a dishwasher. Alternatively, you may just decide that you are fed up with washing the dishes by hand, and you invest in a dishwasher. Consequently, if you are like me, you will want to know how to do it yourself!

The thought of how to install a dishwasher may seem a daunting task. However, most budding DIY people want to tackle the job themselves. And sometimes, you just have to pull up your pants and give it a whirl!

How to Install a Dishwasher

When you wonder how to install a dishwasher, you may experience butterflies in your stomach. However, like any other job, it is a case of following a set of guidelines to lead the project to success.

With a few handy tips and tricks, that dishwasher will be working hard for you in no time.

The first thing you will need to do is to install the electrical circuit. Once you have drilled holes in the cabinets, you may connect your waste pipes and plumb in the water lines. Finally, you may wire the dishwasher in, and the job is complete!

Now you know how to install a dishwasher. But wait, now you look worried. Don’t worry. We will cover each step in detail for you.

Sorting out the Electrics

Dishwasher on the side

VIA: Pixabay

Most of the following, you should be able to do yourself. However, if in doubt, it is always advisable to seek the services of a qualified electrician. After all, you don’t want to be messing around with electrics if you feel uncomfortable.

The electrical circuit

You will need to install a 20 amp circuit from your electrical service panel. You may already have a circuit connected for a dishwasher, but if not, follow these guidelines.

Circuit cable

The first thing you want to do is to install a 12 AWG cable from the dishwasher space to the service panel. However, this may involve drilling holes through to the basement or crawlspace.

You want to leave a good six feet of cable sticking out in the dishwasher space to allow for pulling the dishwasher in and out for servicing.

The circuit

Note: you must use a qualified electrician to install a new circuit breaker for you. Check with your building regulations to ensure you follow the law. Also, ensure you turn the electric off while you undertake any and all the electrical work.

Meanwhile, use duct tape to fix the cable in the dishwasher space to stop it from sliding down the hole.

Preparing the Cabinets

A red cup on a dishwasher

VIA: Pixabay

You will need a drill, a 1.5-inch spade bit, and a 3/4-inch drill bit for the following task.

Drill your holes

You will need two holes, one for the drain hose and one for the water line. Using your 1.5-inch spade bit, drill your first hole near the back of the cabinet and as high as possible. However, you must take care not to hit the sink.

The hole needs to be higher than the dishwasher tub to prevent backwash. You don’t want dirty water siphoning back into your dishes!

Drill the hole for the water line

The last hole is for the water line. You should locate this hole near the sink’s hot water supply pipe. As with all drilling, take your time to avoid damaging existing pipes.

It’s a DrainIt’s a Drain

Plates above the machine

VIA: Pixabay

Now the fun part. It’s time to start connecting some of those pipes.

Connect the drain hose

Feed the drain hose through the larger of the two holes and fit it to the dishwasher drain fitting under your sink.

However, if your sink does not have a dishwasher drain fitting, then you may replace it quickly enough with a tailpiece that has one. The tailpieces screw on and off easily.


If you have a waste disposal unit, you may fit the dishwasher drain hose to its waste pipe. You will see a small round disk called a nipple. Remove the disk by tapping it toward the disposal chamber. Use a punch or a small hammer for this.

Pick out the disc from the waste disposal chamber. You may now use a hose clamp to fix your dishwasher drain hose to the waste disposal nipple.

Let There Be Water

The next step is to connect the water line. Plumbing may seem tricky at times; however, this task is relatively straight forward.

Shut off

First off, you will need to install a shutoff valve on the hot water supply pipe under the sink. Replace the existing shutoff valve with a dual-outlet shutoff valve. This valve will feed both the sink faucet and the dishwasher.

Also, with a simple twist of a valve, you may quickly stop the water from going to either device.

Connect the water line

Using flexible copper piping, fix one end to the shutoff valve under the sink. The 3/8-inch flexible copper piping is ideal for this job. Feed it through the hole in the cabinet and connect the other end to the water supply valve on the dishwasher.

You may need to use a brass fitting with the water valve to accommodate the 3/8-inch pipe.

Use thread seal tape, or PFT tape to the screw joints to help prevent leaks. The tape is extremely thin and acts as an additional seal.

Setting up the Dishwasher

Plates and utensils

VIA: Flickr

It is now time to wire in the dishwasher. In the beginning, you wondered how to install a dishwasher, and now you are nearly there!

Dishwasher panel

Remove the dishwasher plate at the bottom of the dishwasher to reveal the wiring junction box. A screwdriver set or a nut driver will make short work of this. Once removed, you will see a metal junction box on the right-hand side. Remove the bolt on the junction box.

Wire in your cable

A hole in the box will allow you to feed in 6-inches of your electrical cable. Use the clamp inside the box to clamp and fix the cable into position. Strip the cable wires and connect the wires as instructed in the manufacturer's instructions. Follow the instructions carefully to ensure correct connectivity.

Finally, fix the junction box and the plate back into position.

Slide the Dishwasher into Position

Black dishwasher machine

VIA: Flickr

Using a gentle sliding motion, maneuver the dishwasher into position and use a spirit level to ensure the dishwasher remains level. However, make sure you don’t trap the water line or the waste line as you push the dishwasher back.

Once level, secure the dishwasher in place using the brackets supplied, making sure the brackets don’t stick out beyond the edge of the counter or cabinets.

Final Tests

Turn the water back on and check for leaks. If all seems fine, then you may turn on the electric and test your dishwasher by starting one of its cycles. Let it complete its drain cycle and keep checking for leaks.

Congratulations! You have just installed a dishwasher!

Important Considerations

Loaded dishwasher machine

VIA: Flickr

It is always worth checking your local building regulations to ensure you follow the rules and regulations for electrics and plumbing. For instance, some local plumbing regulations require that dishwashers connect to an air gap device.

If in any doubt, it is always worth consulting with a professional. Also, always remember to follow the manufacturer's instructions at all times. Read them thoroughly before you begin.

How to Install a Dishwasher: Answered

You bought your dishwasher and found yourself wondering how to install a dishwasher. However, by following these guidelines, you may find it an easier task than you may have first thought. By taking your time and following the manufacturer's instructions, you have the satisfaction of installing the machine yourself.

Have you installed a dishwasher? Perhaps you have some hints and tips you would like to share with us? Comment in the space below as we would love to hear from you.

Featured image by: Pexels


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