Working Mechanism of Dishwashers

Appliances

A dishwasher is like a robot that cleans and rinses dirty dishes. Although humans have to load the dishes, add detergent, set the washing cycle, and turn it on, the dishwasher carries out all the functions by itself. It adds water, heats it to the appropriate temperature, and automatically opens the detergent dispenser at the right time. The dishwasher shoots water through spray arms to clean the dishes, drains the dirty water, sprays more water to rinse them, drains itself again, and heats the air to dry the dishes if the user has selected that setting.

Moreover, dishwashers have self-monitoring mechanisms to ensure that everything is running smoothly. A timer or a small computer regulates the length of each cycle. A sensor detects the water and air temperature to prevent overheating or damage to the dishes. Another sensor can tell if the water level gets too high and activates the draining function to keep the dishwasher from overflowing. Some dishwashers even have sensors that detect the dirtiness of the water coming off the dishes, and once the water is clear enough, the dishwasher knows the dishes are clean.

The dishwasher has a small basin at the bottom that fills up with water, which is heated up to as much as 155 degrees Fahrenheit (68 Celsius) while mixing in the detergent. Then a pump propels the water up to the spray arms, where it is forced out and sprayed against the dirty dishes. The force of the water also makes the spray arms rotate, just like a lawn sprinkler.

The final step in a wash cycle is optional, which is the dry cycle. The heating element at the bottom of the dishwasher heats the air inside to help the dishes dry. Some people let them dry without heat to save energy.

The dishwasher’s mechanism is not very complex. In the next section, we’ll take a look at the main parts of a basic dishwasher.

Dishwasher Parts

The main parts of a dishwasher include a basin, heating elements, pump, spray arms, filters, and a drying element. The basin fills up with water that is heated and mixed with detergent, and the pump propels the water up to the spray arms to clean the dishes. The filters catch the food particles, and the drying element heats the air inside to dry the dishes.

Control Mechanism

The control mechanism of a dishwasher is located behind the control panel inside the door. It functions using an electro-mechanical system where a timer decides the duration of each cycle and activates the appropriate function at the right time, like the detergent dispenser, wash spray and draining functions. Some high-end models feature a computerized control system while all modern units come equipped with a door latch that must be closed for operation. Certain models also offer child safety locks.

Water Intake Valve

The water intake valve is where water from the home’s water supply enters the dishwasher. This valve is mounted inside the dishwasher and opens and closes to allow the right amount of water into the unit during a cycle. When the valve opens, water pressure forces water into the machine.

Circulation Pump

The circulation pump of a dishwasher is powered by an electric motor and is located beneath the basin in the center of the unit. During the washing cycle, the pump forces water up into the spray arms, and during the drain cycle, it directs the water into the drain hose. There are two types of pumps, reversible and direct-drive. Reversible pumps switch between pumping water to the spray arms and pumping water to the drain by reversing the direction of the motor. In contrast, direct-drive pumps only run in one direction, and the direction of water flow switches from the spray arms to the drain pipe via a solenoid valve. Reversible pumps are usually vertically mounted, while direct-drive pumps are usually horizontally mounted.

Dishwashers can be installed permanently or in a portable configuration. Portable units have finished sides and a top that can be used as a countertop. When not in use, the machine sits in place next to the wall and can be rolled on casters over to the sink and connected to the faucet and an outlet nearby. In permanent installations, the dishwasher goes under the existing countertop and bolts into place. The unit connects directly to the hot water line and the drain line, and it usually plugs in under the sink as well. Both types of installations require a 120-volt grounded line.

Now, let’s explore how to use a dishwasher.

Who Invented the Dishwasher?

The first dishwashing machines consisted of a dish rack on a spindle with a basin of water below it. A hand crank rotated the dish rack, splashing it through the water, but it was not efficient. Josephine Cochrane invented the modern dishwasher in 1886. Cochrane, a wealthy socialite, developed a rack and water jet system after her servants kept chipping her fine china while hand-washing it. It debuted at the 1893 Chicago World’s Fair, and the company she founded eventually became KitchenAid.

Using a Dishwasher

While the dishwasher does most of the work, it’s essential to follow some guidelines to ensure its safe, effective, and efficient operation. Don’t overfill the dishwasher, and make sure to scrape off any large food particles before loading the dishes. Load the dishwasher carefully and make sure to use the appropriate amount of detergent. Don’t interrupt the cycle or open the door while it’s running, and clean the interior of the dishwasher regularly.

The following are some tips for running a dishwasher effectively: avoid using regular dish soap as it causes suds to overflow, don’t overload the dishwasher, place the dirtiest part of the dishes towards the spray jets, separate stainless steel and sterling silver items, keep identical dishes separated to ensure that water reaches every part of the dish, avoid putting wood, cast iron, fine china, crystal, or hand-painted dishes into the dishwasher, use the dishwasher at a time of day when water pressure is high, use slightly more detergent if your home has hard water, use a rinse aid to avoid spots and help dishes dry more quickly, don’t put plastics on the bottom rack, and avoid pre-cleaning dishes.

Detergent is an important consideration when running a dishwasher. Detergents counteract mineral deposits, contain solvents that help dissolve food, have abrasives that scour away stuck-on gunk and help food slide off dishes more easily. Only detergents specially formulated for dishwashing machines will work. Choosing a detergent type depends on personal preference, and it is important that the detergent is fresh, less than two months old, to clean well.

Troubleshooting dishwasher problems includes cleaning mineral build-up that can clog water jets, clearing clogs in the drain hose, and using less detergent to prevent a sudsy dishwasher that can shut down the drain cycle too early.

Guide for Buying a Dishwasher

Smart dishwashers can be started from a tablet. izusek/Getty Images

Modern dishwashers work in the same way, even the cheaper ones perform well in cleaning dishes. Therefore, when buying a dishwasher, the primary factors to consider are durability, size, and convenience. You should look for features that you will use and avoid those that you do not need.

Size

A standard 24-inch dishwasher
Photo courtesy of Consumer Guide Products

Dishwashers come in different sizes. The smallest ones are the countertop and in-sink dishwashers, which can wash up to six place-settings. Countertop units do not require installation as they sit on top of your counter. In-sink dishwashers usually fit into one-half of a double kitchen sink and can wash a complete load in about 20 minutes. When not in use, a cover on the unit allows it to serve as a countertop.

A standard dishwasher is 24 inches (61 centimeters) wide, but there are also 18-inch (46-centimeter) units available, sometimes referred to as “apartment-sized” dishwashers. The wider the dishwasher, the more dishes it can hold. If you have a large family, a 30-inch (76-meter) model might be the right size. Anything bigger than that, and you are probably looking at a commercial dishwasher.

A dish drawer is a unique offering, which is a small dishwasher the size of a large kitchen drawer. It uses less water and energy than a full-sized dishwasher and is suitable for small kitchens that do not have enough room for a full-size unit. However, they also come in double-drawer models that can hold as many dishes as a standard dishwasher. These drawers function independently and are perfect in kitchens where a dishwasher door would block a walkway.

Basins and Racks

Plastic basins are found in lower-end dishwasher models, while some mid- and high-priced units have stainless steel basins. In cheaper models, bits of food settle into a filter that must be manually cleaned regularly. More expensive models have self-cleaning filters, and some include small grinders that grind up large chunks, which drain with the dirty water.

Dish racks come in various configurations. The more you pay for the dishwasher, the more flexibility and adjustability you will get, with collapsible racks, folding tines, extra shelves, and removable racks for loading outside the machine. If you have large or oddly shaped dishes that you will be washing regularly, take them to the appliance store to make sure they will fit the racks.

Extra Features

Today’s appliances are smarter and more energy-efficient, with past upgrades now standard on even the least expensive models. For example, most dishwashers now feature a soil sensor that saves water by sensing how dirty your dishes are and adjusting the wash time and water amount accordingly. Other energy-saving options include half-load and speed-wash cycles.

Dishwashers come with a range of features, with more expensive models offering WiFi connectivity, enabling you to control your appliance from your smartphone. You can operate your dishwasher remotely, check remaining cycle time, lock buttons when children are at home, and receive alerts for low rinse aid or possible leaks. Advanced features include a third rack for flat items, bottle jets for cleaning baby bottles and water bottles, and adjustable racks. Stylish dishwasher designs with noise suppression are also available at a higher cost. Dishwashers with grinders are noisier than those without them. The U.S. government’s Energy Star program lists the most efficient dishwashers each year to help you select a model that’s environmentally friendly and cost-effective. The cost of dishwashers varies from $600 for a basic model to $2,000 for one with every possible feature, including WiFi connectivity, additional cycles, hidden controls, LED lights, built-in water softeners, and water cleanliness sensors. Energy Star certified dishwashers are 12% more energy-efficient and 30% more water-efficient than standard models, costing about $35 annually to run. They save approximately 3,870 gallons of water over their lifetime and 7,000 gallons annually compared to handwashing dishes, providing an extra 230 hours of time and saving $111 on utility bills. Commercial dishwashers are heavy-duty machines capable of washing dishes quickly and sterilizing them at a temperature of at least 160 degrees Fahrenheit.

Dishwasher FAQ

Are dishwashers worth buying?

Yes, dishwashers are worth buying due to their cost and energy efficiency. They are especially useful for large families and offices. If you have a smaller household, a double drawer dishwasher may be a better choice.

How do I select a dishwasher?

A good dishwasher should have a high unit capacity for handling many dishes and large dishware. Look for additional wash cycles like “rinse and hold,” “quick wash,” “sanitize,” and “delicate.” Finally, consider the energy usage of the appliance.

How do portable dishwashers drain?

Portable dishwashers can be drained using a “unicouple” that can be attached to a kitchen faucet. The unicouple has two hoses, one for the dishwasher and another for the sink.

Do portable dishwashers work as well as built-in dishwashers?

Portable dishwashers are more efficient at cleaning for smaller households. However, they have a lower unit capacity compared to built-in dishwashers and have some limitations. They may be a good option for families who are renting their homes.

Lots More Information

What’s the Best Way to Load a Dishwasher?
Stop Hand-washing Your Dishes!
How to Repair a Dishwasher: Tips and Guidelines
How Washing Machines Work
How Central Vacuum Systems Work
How Vacuum Cleaners Work

Sources

Appliances Connection. “Top 5 Dishwashers Under $1,000 of 2021.” April 5, 2021. (Aug. 18, 2021)
https://www.appliancesconnection.com/blog/top-5-dishwashers-under-1000
Brown, Scott M. “Appliance Tip of the Day: Dishwasher Drainology.” FixItNow.com, February 2003. http://fixitnow.com/2003/02/appliance-tip-of-day-dishwasher.htm
Consumer Reports “Dishwasher Buying Guide.” Consumer Reports. July 1, 201. (Aug. 18, 2021)
Consumer Reports “Dishwasher Buying Guide.” Consumer Reports. July 1, 201. (Aug. 18, 2021)https://www.consumerreports.org/cro/dishwashers/buying-guide/index.htm
EnergyStar. “Dishwashers.” EnergyStar.gov.
EnergyStar. “Dishwashers.” EnergyStar.gov. http://www.energystar.gov/index.cfm?c=dishwash.pr_dishwashers
Energy Star. “Energy Star Most Efficient 2021 Dishwashers.” (Aug. 18, 2021)
Energy Star. “Energy Star Most Efficient 2021 Dishwashers.” (Aug. 18, 2021)https://www.energystar.gov/most-efficient/me-certified-dishwashers
Energy Star. “How much water do ENERGY STAR dishwashers use? Is there a water-efficiency metric (“water factor”) for ENERGY STAR dishwashers like there is for ENERGY STAR qualified clothes washers?” Sept. 15, 2020. (Aug. 18, 2021)
Energy Star. “How much water do ENERGY STAR dishwashers use? Is there a water-efficiency metric (“water factor”) for ENERGY STAR dishwashers like there is for ENERGY STAR qualified clothes washers?” Sept. 15, 2020. (Aug. 18, 2021)https://energystar-mesa.force.com/ENERGYSTAR/s/article/How-much-water-do-ENERGY-STAR-dishwashers-use-Is-there-a-water-efficiency-metric-water-factor-for-ENERGY-STAR-dishwashers-like-there-is-for-ENERGY-STAR-qualified-clothes-washers-1600088468515
Forte, Carolyn. “6 Best Countertop Dishwashers for 2021, According to Cleaning Experts.” Good Housekeeping. Aug. 12, 2020. (Aug. 18, 2021)
Forte, Carolyn. “6 Best Countertop Dishwashers for 2021, According to Cleaning Experts.” Good Housekeeping. Aug. 12, 2020. (Aug. 18, 2021)https://www.goodhousekeeping.com/appliances/dishwasher-reviews/g33438785/best-countertop-mini-dishwashers/
Forte, Carolyn. “How to Use and Load a Dishwasher the Right Way,” Good Housekeeping. Nov. 13, 2019. (Aug. 18, 2021)
Forte, Carolyn. “How to Use and Load a Dishwasher the Right Way,” Good Housekeeping. Nov. 13, 2019. (Aug. 18, 2021) https://www.goodhousekeeping.com/appliances/dishwasher-reviews/a22031/dishwasher-tips-0306/
Hall, Janet. “Remodeling 101: The Ins and Outs of Dishwasher Drawers.” Remodelista. Aug. 17, 2017. (Aug. 19, 2021)
Hall, Janet. “Remodeling 101: The Ins and Outs of Dishwasher Drawers.” Remodelista. Aug. 17, 2017. (Aug. 19, 2021)https://www.remodelista.com/posts/appliances-dishwasher-drawers/
Hans, Jennifer Dawn. “The Dirt on Dishwashers.” Home Appliance Magazine.

The following is a list of sources regarding dishwashers:

– “Inventing the Dishwasher” by John H. Lienhard, 1999

– “What Actually Happens Inside Your Dishwasher?” by Julia MacDougall, Reviewed, Dec. 8, 2020

– “How Dishwashers Work” by Maytag, accessed Aug. 18, 2021

– “What Is a Smart Dishwasher?” by Renée Lynn Midrack, Lifewire, July 2, 2021

– “Dishwasher Buying Guide” by Don Vandervort, HomeTips.com

– “Guide to parts of a dishwasher” by Whirlpool, accessed Aug. 18, 2021

The sources cover a range of topics related to dishwashers, including their history, how they work, smart technology, purchasing advice, and a breakdown of the parts.

FAQ

1. What is a dishwasher and how does it work?

A dishwasher is an appliance designed to clean and sanitize dishes, glasses, and utensils. It works by spraying hot water and detergent onto the dishes, then rinsing them with clean water. Some dishwashers also have a drying cycle that uses hot air to dry the dishes.

2. What are the different types of dishwashers available?

There are several types of dishwashers available, including built-in, portable, and countertop models. Built-in dishwashers are installed under the counter and are typically the most popular type. Portable dishwashers are on wheels and can be moved around, while countertop dishwashers sit on top of the counter and are smaller in size.

3. How do you load a dishwasher properly?

To load a dishwasher properly, make sure to place dishes in a way that allows for maximum water flow. Plates should be placed facing the center of the dishwasher, while glasses and cups should be placed on the top rack. Utensils should be placed in the utensil basket with handles facing up.

4. Is it necessary to pre-rinse dishes before placing them in the dishwasher?

No, it is not necessary to pre-rinse dishes before placing them in the dishwasher. Most dishwashers are designed to handle food particles and debris, and pre-rinsing can actually waste water and energy.

5. What types of detergent should be used in a dishwasher?

There are several types of dishwasher detergents available, including powder, liquid, and gel. It is important to choose a detergent that is specifically designed for use in a dishwasher and to follow the manufacturer’s instructions for use.

6. Can plastics be safely washed in a dishwasher?

Most plastics can be washed in a dishwasher, but it is important to check the packaging or manufacturer’s instructions before placing them in the dishwasher. Some plastics may melt or warp under high temperatures.

7. How often should a dishwasher be cleaned?

A dishwasher should be cleaned regularly to prevent buildup of food particles and debris. It is recommended to clean the dishwasher once a month by running an empty cycle with a dishwasher cleaner or a cup of vinegar.

8. How long does a typical dishwasher cycle take?

The length of a dishwasher cycle can vary depending on the model and settings used. A typical cycle can take anywhere from 1-3 hours to complete.

9. How can you troubleshoot common dishwasher problems?

Common dishwasher problems include dishes not getting clean, water not draining properly, and strange noises during operation. To troubleshoot these issues, it is recommended to check the dishwasher’s filter, drain hose, and spray arms for clogs or damage. It may also be helpful to consult the manufacturer’s manual or contact a professional for assistance.

Brody Stewart
Brody is a skilled craftsman and gardening expert. From renovating living spaces to cultivating lush gardens, Brody’s knowledge and passion shine through, inspiring readers to embark on their own home improvement and gardening journeys with confidence.