How Does a Dishwasher Work?

How Does a Dishwasher Work?

Dishwashers are one of the most common appliances found in homes across the United States, but how does a dishwasher work? How does the detergent get released? How does water get onto the dishes? Throughout this page, I will teach you all of the components and processes that occur during a normal washing cycle. 

Main Parts of a Dishwasher

Besides the rack where you place your dishes, there are three main parts of a dishwasher. 

Heating Element

The heating element is a piece of metal that converts electricity into heat. This is used to heat the water during the washing and rinsing cycles. 

Spray Arms and Jets

These two components are hollow pieces of pipe that the water runs through. If you were to open your dishwasher during the washing or rinsing process, these would be the parts that are spraying the water. The spray arms spray the water by spinning. This spinning is caused by the pressure of the water that runs through them. 


The pump is a motor that makes sure that the water is going into and out of the correct parts. It is used to pull in and pull out the water at the beginning and end of the cycle or when the water gets too dirty. 

How Does a Dishwasher Work?

Putting dishes in dishwasher

There are about five steps included in the cleaning process. The number of steps will be determined by which settings you choose at the beginning. For example, if you set the dishwasher to do two rinsing cycles, it will add one more step to the process. 

Preparation Cycle

During this cycle, water will be pumped into the bottom of the dishwasher (also called the basin). If the water is not at the correct temperature, the heating element will be used to warm it up. The water continues to be pumped in until the basin is filled with two to three inches of warm water. The dishwasher is able to figure out when this level has been reached due to specialized sensors. 

Washing Cycle

At this stage, two things occur simultaneously. First, the pump pulls the water from the basin into the spray arms and jets. After enough water is built up, the pressure of it causes the spray arms to spin. DO NOT open your dishwasher at this stage or else you might be sprayed in the face. The pressure of the water is no joke. In fact, the pressure of the water alone is what allows it to reach both the top and bottom racks.

Second, the container holding the detergent is opened. The spray jets will dilute the detergent into a liquid solution. This liquid solution will go down toward the bottom of the dishwasher. The pump will then pick up the solution to go into the spray arms and jets. This is when the detergent first hits the dishes.

After a while, a cleanliness check may be done. A cleanliness check is a dishwasher determining if the dishes are clean. It does this by a sensor reading how clean the water is dripping off of the dishes. This check is only done in more advanced dishwashers. If your dishwasher doesn’t have this function, it will continue washing the dishes for an allotted time. 

Draining Cycle

During the draining cycle, the pump pulls the dirty water in the basin of the dishwasher into the sewer system. 

Rinsing Cycle

After the draining cycle, the dishwasher will pull back in clean water into the dishwasher’s basin. If you put a rinsing agent into your dishwasher at the beginning, this is when the container will open. After the container opens, the rinsing agent will mix in with the water in the bottom of the dishwasher. The pump will then (once again) force water into the spray arms and jets to rinse the dishes. At the end of this cycle, the water will be pumped out and drained into the sewage system. 

Drying Cycle

There are two types of drying cycles that you can employ. The first is to allow the dishes to dry naturally. The second is to do a machine drying cycle. Some dishwashers will automatically do this (especially newer, more advanced ones). Others have a setting that you must select. Some don’t have this feature at all. During the machine drying cycle, the heating element will be activated until the temperature inside the dishwasher reaches a certain point. At that point, the warm air will cause water to begin to evaporate (turn into steam) which dries the dishes. This process might take about an hour. 

Maintenance of Dishwasher

Cleaning methods

In order for your dishwasher to clean its best, it is recommended that you do these types of maintenance. 

Run Dishwasher Regularly

When a dishwasher just sits for multiple days, it begins to form hard-water deposits. This can impact the spray jets, spray arms, and pump. If you do need to leave the dishwasher unused for a few days, use dishwasher cleaning solutions or tablets to help break these deposits up. It is recommended to do this every month or so. If you don’t want to spend the money on a dishwasher cleaning solution, you can try to put in one cup of white vinegar and run the dishwasher without any dishes in it. This may leave a smell. 

Clean Interior

You can clean the interior of your dishwasher with an all-purpose cleaner or anti-bacterial wipes. This should also remove any odors that are present. 

Check Drain

Between the basin and the pump, there is a drain to catch any large food particles. This drain is put there to prevent any clogs in the hose that feeds to the sewage system. To clean this drain, I would recommend using a bristle brush (such as a dish scrub brush) to gently scrub off the food particles. This should be done about every month to keep things running smoothly. 

Check Seal

Every dishwasher contains an air-tight seal to prevent water from leaking out from the dishwasher. It surrounds the dishwasher’s door. Make sure to check this sporadically for cracks. You should also wash this every month or so. Because it is exposed to everything that happens during the cleaning process, it may get food or other particles on it. You can wash this away with a dish soap-covered paper towel, multi-purpose cleaner, or anti-bacterial wipe. 


There are about five steps that are gone through when you run your dishwasher. Different dishwashers and different settings will impact how many steps that a dishwasher must execute. To ensure that your dishwasher is cleaning to the best of its ability, make sure to maintain it. 

Written by Allison Knowles

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