How Does a Dishwasher Work

Do you know how your dishwasher works? Probably not. Chances are when you’re done loading it up with dirty dishes and turn on the cycle, you walk away and let it do its thing.

A dishwasher is an energy-efficient appliance that’s designed for people who hate doing dishes by hand. It does the dirty work of washing and drying your dirty dishes, so you can move on with your life.

Dishwashers come in all shapes and sizes. From portable dishwashers for apartment dwellers to large-capacity commercial dishwashing machines that clean thousands of dishes at once.

But how does a dishwasher work anyway? It’s time to find out!

How dishwashers work in a nutshell

A dishwasher’s basic function is to wash your dirty dishes. But how does it accomplish this?

  1. You first add some water through the inlet into the shallow basin at the base.
  2. Once set up, the dishwasher heats this water using the heating element found at the bottom of each unit.
  3. Afterward, the machine will add dishwashing detergent, usually in liquid, solid, or powdered form. There are normally timers and special sensors that know when and how much to release into the water.
  4. The hot, soapy water then goes through the pump. It then gets forced out through powerful jets of water that bounce off your plates to clear the dirt on their surface. (This happens with the help of the sprayer arms found below each rack)
  5. The dishwasher may repeat the wash cycle depending on the load and how dirty your dishes are. After rinsing, the dirty water gets drained out through the outlet found at the base of most dishwashers.
  6. For the rinse cycle, clean water comes in and gets heated first. When the water’s hot enough, it again gets pumped up and out through the spray arms to clear the gunk and dirty, soapy water off your utensils. (This step may also repeat if necessary)
  7. For the drying cycle (final process), hot air from the heating element below circulates around the rinsed utensils for a while and evaporates the water.

Note: Some dishes might still have bits of food left behind after washing. That’s why it’s important to scrape off excess food from your plates before putting them in your dishwasher.

Dishwashers 101

The dishwasher was first invented by Josephine Cochrane in the later part of 1886. She wanted women to be able to spend less time cleaning dishes after meals with friends and family.

After creating her prototype model, it was widely received by everyone who heard the idea.

Today there is no need for you or your wife—or husband (let’s not forget about them!)—to go through that process anymore.

Over the years, there have been more improvements to the design and overall performance. All these efforts were mainly put in place to increase the effectiveness and efficiency of the machine.

One thing stands out in all of them though…

That is, they all have these basic components:

  • hot or cold water supply line
  • heating element
  • controls (timer)
  • pump & motor assembly
  • door latch mechanism
  • spray arms or washer jets (depending on the type of machine)
  • detergent dispenser drawer/spout/sump

Let’s take a keener look at them below…

Dishwasher components and how they work to clean your dishes

a. Base

The dishwasher has a base that holds water while it’s in use, which also acts as the drainage tray when finished.

The base of a dishwasher also carries the heating element, water inlet/outlet, and a spray arm for the lower rack.

b. Spraying arms

This part of the machine uses pressure jets to spray out hot, soapy water onto all surfaces of dirty dishes. It does this well through small holes on its arms that create a powerful jet of water.

This force helps loosen up food particles trapped inside plates or cups and then washes them away. It also carries along any debris leftover from previous cleaners (like sponges or rags) into an internal drain located at the bottom of the basin. All this grime will then get removed later on during the draining cycle.

There are two different kinds of spray arms found within most commercial washers. They include either single-piece or two-piece.

The single piece is more common and has a detachable nozzle that fits into the arm to hold it in place.

A two-piece sprayer consists of an upper portion attached by screws to the dishwasher frame itself inside. It sits below a lower section with holes all across its surface.

c. Filters

Dishwashers also contain filters at the lower basin. They serve to trap food particles so they don’t get washed away while spraying water onto dirty dishes.

Mesh filters are often used because they’re much easier to clean instead of replacing them once worn out from too many cycles.

d. Heating element

A heating element warms up your tap inlet water at the bottom of the dishwasher. Most of the time, the water would range between 50° – 60°C (or 140°F).

Sometimes, it may become even hotter depending on how powerful your model’s elements are. This heated will then splash around your dishes to get rid of gunk and harmful bacteria.

e. Timer

The timer ensures that all components work at an optimum pace and efficiency when you run a cycle.

The timer motor turns on or off depending on how far along the process is. It automatically stops once complete so hot air from the heating element below can start the drying cycle.

Usually, these controls come located on the dishwasher’s door. The controls may come placed somewhere else in some models but within close reach on the front-loading models. (like in modern dishwashers that often have touchpads nowadays)

f. Water Inlet Valve

This component regulates how much water flows in during each wash cycle. It ensures the dishwasher fills up with at least a pitcher of water. (Yes! Dishwashers do not fill to the brim)

The water inlet may get connected directly to your home’s cold-water supply line. Yet in other models, you may need to attach it straight to your sink’s faucet.

Also, the inlet valve uses an electrical switch that either turns on or off depending on how far along the cycle is.

g. Draining Pump & Motor Assembly (depending on model)

This part works by draining dirty, soapy water from washing dishes. The dirty water goes down into a drain hose located inside the base of the machine.

The pump then pushes this reserve out of the basin at the bottom before rinsing or drying. The dirtied water gets pushed out through an outlet tubing. It then gets discharged outside via any nearby plumbing fixtures.

For some homes, you may find dishwasher outlet drainage fixed within the kitchen walls. For others, you may need to manually set up your outlet drainage in your kitchen to suit your dishwasher.

h. Door Latch Mechanism

Your dishwasher won’t run without a door latch. This lock ensures the dishwasher can only open when it has finished its cycle.

If left open with water on board, it’ll cause an overflow that will flood your kitchen floor and countertops.

To close properly, there are usually three locks within each unit:

  1. one located at the bottom center of the hinge side
  2. another inside top-side near opening handle/button area
  3. the last may be also found in between the above two areas

Most models may just have these three.

Some, like commercial units, may come equipped with more than six locks depending on how complex their build is.

i. Dishwasher detergent dispenser

The detergent dispensers are mostly found inside the dishwasher on the upper side of the door.

Most units have a compartment with three holes. These allow soap solution and water to mix before getting released into your dishwasher’s basin below.

Others may come equipped with two compartments (one for pre-wash, one for main wash) while still others may contain up to four separate compartments depending on how many cycles they offer in total.

To open this port, usually, there would be a handle/latch located nearby. This is so you won’t need to take their entire unit apart just to access the compartment.

Dishwasher detergents come in powder, liquid, or solid (tablets) versions.

j. Dish racks & Cutlery Basket/Tray

These components are where you place your dirty utensils before starting up your washing cycles. You need to arrange your plates, bowls, mugs, and glasses vertically on their sides for the best results.

How many items you’ll store inside one unit will depend on how big or small the trays are. (smaller homes may require smaller-built units for example)

Typically, you’ll find three standard compartments in most models. These include:

  1. one for the cutlery tray (where knives and forks will get loaded)
  2. another compartment where plates/bowls go inside
  3. a third area that is mostly designed to hold glasses or mugs upright.

You’ll want your utensils laid out properly within each rack so they don’t shift positions.

Tips for how to use your dishwasher

Looking for tips that could help you get the best out of your dishwasher? Check out a few I find very useful below:

  1. Wash only a full load, or use the half-load setting on some machines to avoid overflow and rewashing.
  2. Consider how often you want to run your machine to manage your energy costs. Some folks do 2-3 times per week while others let them pile up all week for a single wash.
  3. Add vinegar once per month if you live in an area with hard water. This helps to prevent clogging that can reduce the effectiveness of the cleaning spray jets.
  4. Avoid placing your plastics on the bottom tray. This is because the heating element beneath the lower rack can melt them.
  5. Use your machine only when you have optimal water pressure in your house. This ensures that your dishwasher gets the water power it needs to clean your stuff up.
  6. Do not overload your racks as it could prevent water sprays from reaching other parts of the utensils.
  7. Only use dishwasher soap as regular dish soaps create suds that overflow your dishwasher.
  8. Place the dirtier parts of your dishes facing the cleaning spray jets for maximum effect.
  9. Do not put fine china, cast iron, wood, or crystal dishes in your dishwasher. These items are better off washed using your hands.
  10. You can use a rinse aid to prevent soap scales from building up. It also makes the drying process much faster.

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