How does a Dishwasher Work – Parts & Steps Outlined


One more question that has come up numerous times in the community and that is how do dishwashers work so if you are interested in knowing the main parts and some steps in the operation of a dishwasher, then read on…

A Dishwasher is a useful appliance in your kitchen that cleans your dirty dishes and cutlery automatically. All you have to do is to load the dishes, glasses, cups, and cutlery, add detergent, set the cycles depending on the load and just turn it on. Within an hour or two you will and clean sparkling dishes and cutlery fully cleaned and washed. I will explain here how a dishwasher works.


A dishwasher is essentially a watertight box, though water is not filled in the box except just in a shallow basin in the bottom. There are racks and baskets for various stacking different types of crockery and silverware. Water is heated up to 130 to 140 degrees Fahrenheit and mixed with detergent sprayed powerfully on the dishes by a spraying mechanism. There is a water filtering mechanism to re-use the circulating water. This cycle is repeated many times with different pressure and speed of water until all items are left clean. Finally circulating hot air dries the dishes. Following are the main parts of a dishwasher:


A water pump is the essential part of a dishwasher. It is driven by a powerful electric motor.  During the cleaning cycle, this pump produces high-pressure water which shoots through the spraying mechanism at high speed. During the drain cycle, this pump drains the water from the dishwasher into the water drain and in the pump cycle, the pump forces water up into the spray arms. In the drain cycle, the pump directs the water into the drain hose. The motor-pump assembly is mounted beneath the basin, in the center of the dishwasher.

Spray Arm

The water from the pump comes out at high pressure from two spinning paddles. One is located at the bottom of the dishwasher and is normally made of stainless steel and the other is at the top, made of plastic. These paddles have fine holes, when water is forced into the paddle it comes out as a jet at high speed. This also results in the paddles to spin like garden sprinklers.


There is an electric element heater that heats the water so over 140 degrees Fahrenheit. This hot water helps in removing grease from dirty plates.


There are various valves that are electrically operated, an intake valve to let the water in from the mains, and other valves which open and close to change the flow of water as required.


There is a filter in the water circulating circuit that removes any solid material from the water during the wash cycle.

Control mechanism

It is located in the door, just behind the control panel. The older models had electro-mechanical switches to activate various functions during the washing process. The newer ones have an electronic or computerized control system. There is a safety latch that inhibits the operation of the dishwasher if a door is open.

Operation of the Dishwasher

Once you load the dishes, detergent, select the wash cycle and press the start button the machine starts it automatic process.

Step 1:

Inlet valve open which allows cold water from the home water supply to enter the dishwasher and fill in the lower basin.

Step 2:

The water is heated by the heating element until it reaches the desired temperature as determined by the control system. Usually, it is between 86 to 140 degrees Fahrenheit. As this is much hotter than that what anyone would use for washing by hand it is more hygienic as it kills bacteria and cleans faster.

Step 3:

The electric pump forces water through the lower spray paddle while spinning to jet water on the dirty dishes. Slightly cooler water jets down from the top paddle similarly cleaning the dishes.

Step 4:

Water that falls back to the basin is re-heated filtered and pumped again to the spray paddles.

Step 5:

Detergent is added at the appropriate cycle. The hot water with detergent sprayed on the plates is the main cleaning action.

Step 6:

The cycle is repeated many times. And before the final cycle, the water is drained and fresh water is filled in the basin and the water sprayed on the dishes to rinse clean the detergent from dishes.

Step 7:

Water is drained and a hot air cycle dries the dishes.

The dishwasher is a very convenient and time-saving appliance. Not only it saves your time and effort but also saves water as compared to hand washing and is therefore eco-friendly.


While you are here, feel free to view larger a selection of popular Dishwashers and Detergents by clicking on any of the images provided below...


Finally, it would be greatly appreciated by the community if you can share your own experiences of using a Dishwasher good or bad by leaving a comment in the comment box below – So that people in the community can learn also!


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