How to Plumb a Dishwasher Without a Sink – A Step by Step Guide


A kitchen sink can be used when combined with a dishwasher. This combination makes kitchen administration easy and relaxing. You may fail to set up the dishwasher in conjunction with the sink if you have a small kitchen with poor spacing. There is no need to fret about it because you can utilize a dishwasher with no sink. Draining and managing your dishwasher will become easy once you understand how to plumb your dishwasher that doesn’t have a sink. It will require an island in your dishwasher to connect without the sink.

How to plumb a dishwasher without a sink

It is still possible to plumb it even when you don’t have a sink needed to put in the dishwasher. However, you’ll have to complete further to complete the plumbing. It is necessary to be able to join the dishwasher to the P trap in a different manner and then connect it to the Tee branch.

In addition, you’ll have to connect the dishwasher using the air gap before connecting it through the drain pipe. In the following steps, we will look at the entire procedure.

Read now to learn: How to clean a dishwasher rinse aid dispenser

Step 1

Some essential items to planning a dishwasher drain installation without a sink. The draining process will operate with no sink. Alternative methods can be complicated. In addition, you’ll require these things to complete the installation of drains.

  • P-trap
  • Braided supply hose
  • Tee branch
  • Air gap
  • Tape for plumbing
  • Screwdriver
  • Allen wrench

Step 2

After everything is set, you must join the P trap to the dishwasher when everything is ready. To do this, connect the more extended tailpiece of the dishwasher to the P trap. You’ll need to join the two pieces using the slip nuts with screws. It is essential to select the correct size P trap. So, look at the dishwasher drain size and set the appropriate p trap. If you use the proper P trap, connecting it to the more extended tailpiece is necessary. After you have secured the connection, you can use Teflon or a plumber’s tape to secure the point of contact.

Additionally, it is helpful to use an adhesive washer to seal the connection between the P trap and the tailpiece to make the whole system waterproof. The plumbing tape can prolong the life of the connecting point. It prevents mold and residue growth at the end of the connection, making the maintenance of your dishwasher simple.

Step 3

The dishwasher tee can be found beneath the dishwasher. It lets the dishwasher expand the drainage attachment so that it can connect to the drainage systems in your home. Once you have connected it to the dishwasher, it will be required to connect it to the opposite side of the P trap. You should now begin working on the drain hose in the dishwasher. It is necessary to connect it to the point of entry to the air gap before draining it. Inlet to the air gap will usually be the more significant part. Therefore, it shouldn’t be a problem to find it.

Step 4

It’s now the moment to link the primary draining line to the dishwasher. The draining hose will always go across the high loop or air gap attached to the loop first. After it has passed over the circle or the hole, it will connect to the line for draining. There is no dishwasher sink, so it will not have a garbage disposal. This means that you have to install the plumbing system, but without having a garbage disposal. It will require an adapter fitting for branching the tailpiece of the dishwasher to the drainage line.

After connecting it to your draining pipe, it is time to secure the connection. We recommend using the clamp made of metal and the plumbing tape to fix it. If you don’t connect the clamp properly, the relationship could soon be loose and require repair.

Step 6

You’ll need to connect the dishwasher to the supply of the water line. You’ll need the hot water line to do this. You can click the dishwasher using an extended hose to the hot water faucet or water supply point. Find the valve that opens water for your dishwasher. Connect the steel braided water supply hose to the valve for the inlet. Check that it can handle any hot water source without damage. Connect the other end to the closest shut-off valve of the hot water supply. This tube for water is identical to the one you would use for bathrooms or kitchen sinks.

For the correct size dishwasher hot water line and to get it, you must measure how far between your dishwasher and the hot water line. Also, you will require an elbow with a 90-degree angle to connect the supply hose to the dishwasher. This fitting is known as a brass fitting due to its brass-based material. Be sure to purchase an excellent brass fitting to ensure it won’t cause corrosion quickly and rust.

Step 6

The dishwasher’s performance is dependent on the proper venting and electrical lines. Connecting the electrical wiring only if you’re confident enough is possible. Similar is the case with the venting system. We suggest you contact an expert to repair the dishwasher’s electrical venting and wiring system.

It’s crucial as an improperly installed dishwasher electrical system can cause damage to the plumbing system. It could even cause injury to you. Therefore, protecting your plumbing system and the electrical wiring in your dishwasher is essential.

How to plumb a dishwasher without a sink: Things to consider

As you don’t have a sink, you’ll need to build an additional supply line and a drain line. We’ve talked about the plumbing system for the dishwasher without a sink. However, if you want to install a drain for your dishwasher with no sink properly, it is essential to consider the following important aspects.

Make sure you check the supply lines

There is no sink to connect the dishwasher to the water supply, and you’ll need to click separate supply lines for the island of the dishwasher. The island dishwasher plumbing supply line will require getting underneath the cabinet. Additionally, as we’ve stated, you’ll require running through the hotline. Therefore, the water supply line connection to your water heater will be necessary. You can also use dishwashers to warm the cold water to wash your dishes. It allows you to connect your dishwasher to the easily accessible lines for cold water.

Think about the electrical system and ventilation

The electrical outlet in your dishwasher is a crucial aspect to consider. It must be rated at 20 Amps to be able to handle the electric power required by the dishwasher. Make sure to connect the electrical wiring to the designated outlet using GFEC grounding to ensure safety.

Then, think about how you can vent the system. It is essential to open the drain pipe to ensure that the water can flow through the hose at the proper pressure. This allows the water to drain efficiently. An island loop vent is necessary if you use the island dishwasher but not the sink. It runs underneath the countertop of the dishwasher and delivers maximum airflow for the drainage pipe.

Find out the drain’s distance

Also, you must measure the distance between your dishwasher and the drainpipe system. It is also possible to join an island-style dishwasher to the sink drain in a space. If you can measure the distance precisely, you can select the appropriate drain and supply pipes’ length. If you choose your drainpipe and length, remember that the dishwasher will vigorously eject the water after use. The appliance does this by using its discharge pumps. Therefore, you’ll need an extended hose that is longer than what you need from the dishwasher from the draining point to manage this pressure.


You should now be able to plumb a dishwasher without a sink. The plumbing system for dishwashers isn’t as complicated as you might think. However, you should have a minimum of plumbing knowledge. In addition, you should contact an experienced plumber to install the venting system to ensure that the water flows smoothly. It is essential because incorrect wiring or venting may be a mistake.

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