How does my Dishwasher Work?

The Cycles

It is obvious that a dishwasher uses hot water and specially designed detergent and rinse agents to clean, disinfect and dry your dishes. Too bad the dishes cannot put themselves in the dishwasher.

The machine fills with water and then sprays the water over and under the dishes. This cycle is repeated several times and the dishes come clean. Most dishwashers today have soft food disposers in them, making pre-rinsing unnecessary. Various cycles are available and the main difference between them is the number of wash cycles and the length of time the dishes wash. The Pots and Pans cycle, or sometimes called the Heavy Duty cycle is simply longer wash times. These times vary from manufacturer to manufacturer but are generally about 10 or 12 minutes longer than regular cycles. The short wash cycle is normally one rinse less than the normal cycle and cuts about 6 or 7 minutes off of the wash time.

Dishwasher Front Panel
Dishwasher Front Panel
Dishwasher Controls
Dishwasher Controls

Dishwasher Mechanics

The dishwasher goes through the wash rinse cycles controlled by a timer. The timer is similar to the one you may find on your washing machine. This timer controls the cycles and times them. At the end of the cycle, a heater is turned on, and the dishes are dried.

The water level is controlled by a float that turns the water off when a specified level is reached, this is roughly like the float in the toilet that shuts the water off. The water is then cycled through the dishwasher.

When the cycle ends the water is pumped out.

View of the Water Level Float
View of the Water Level Float
View of the Water Level Float
View of the Water Level Float

Common Dishwasher Problems


Leaking is probably the biggest problem with dishwashers and the problem that can cause the most trouble and damage. A dishwasher is hooked up to your hot water source. If the float inside should fail, then the dishwasher will allow hot water to flow into the dishwasher and it will flow out onto the floor.

Probably the number one problem in dishwashers is: Water won't pump out, this is common and can be caused by blocked screens, drain, anti siphon device, or bad pump.

Dishwasher will not complete the cycle. This usually means that the timer is bad and won't advance the dishwasher through its cycles.

Screen in the back of dishwasher
Screen in the back of dishwasher
Screen in bottom of Dishwasher
Screen in bottom of Dishwasher

Loud screetching sounds usually mean that the pump is bad, but might be that the soft food disposal is stuck or rubbing on something. The biggest culprit here is a piece of glass lodged in the screen.

Water will not come into the dishwasher. This can be caused because someone has turned the water source off, the timer is bad and won't call for a fill or the float is stuck and will not call for water.

About Dishwashing Detergent

Does it matter what kind of dishwasher detergent is used?

There is a resounding yes to this question.   Some inexpensive or  bargain dishwashing detergents contain abrasives such as sand.  This can shorten the life of the dishwasher, damage dishes, especially glass and china.  Choose a good name brand dishwasher detergent.   Buying the cheap stuff is penny wise and pound foolish.

Do you need a rinse agent?   Good question but it applies individually.   Do you have soft water, do you have a water conditioner installed for your house water?  Does your water have low mineral content?   If the answer to these questions are yes, you should not need a rinse agent.

If you water is hard, has lots of minerals, and leaves spotting, you need a rinse agent.  It uses surfactants that make it difficult to form water droplets.

Dishwasher Features

Sanitize: This feature raises the temperature of the water to a level that will kill bacteria and viruses. This is not a cost saving feature but it should be used occasionally, especially when there is an illness in the household like flu or cold. Although it does not actually 'sanitize' the surfaces, it does help a lot.

Rinse and Hold: This is a nice feature on dishwasher when you do not need to wash the load and are holding the dirty dishes for a full load. After each meal you can rinse the dishes and hold them for the full load. It goes through one cycle of rinsing and then shuts off keeping the dishes ready for the wash.

Pots and Pans Cycle (or Heavy Duty): This is a longer wash that also normally adds a wash cycle for hard to wash heavily soiled utensils and pots. Some dishwashers also boost the water temperature. Most cooks agree that a dishwasher is not a good place to wash prized cookware, the abrasives and harshness of the detergent can damage quality cookware, dulling aluminum and copper. Cast iron cannot survive a lengthy hot water soaking well.

Plate Warmer: Some dishwashers have a plate warmer feature that is useful for serving some recipes that call for warm or hot dishes. This is a feature that should be used sparingly due to the cost and inconvenience. An oven would work better.

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Comments 12 comments

justom profile image

justom 6 years ago from 41042

I had no idea about how that damn thing worked. I don't care what they say I still have to rinse them before going into the washer. I too am waiting for them to put themselves in! Good hub, Peace!! Tom

allpurposeguru profile image

allpurposeguru 6 years ago from North Carolina

Very interesting. I agree that it's important to pre-rinse. Otherwise, no matter what the advertisements say (for either dishwashers themselves or the detergents) I'll just be pulling some dirty dishes out at the end of the cycle.

Actually, what would be better than having dishes put themselves in the dishwasher would be to have them air-wash, air-sanitize, and put themselves away. That would take less water and save a bundle on detergent, as well as time!

drbj profile image

drbj 6 years ago from south Florida

So that's how dishwashers work! The appliance kind, that is. Haven't had any problems with my dishwasher yet because I seldom use it. Instead, I eat Chinese dinners from containers with chopsticks and Italian pizza with my hands. Also use paper plates, the thin cheapo kind for myself; and the more expensive plasticized paper plates for guests. For real food requiring real plates, I often visit restaurants.

lorlie6 profile image

lorlie6 6 years ago from Bishop, Ca

Those dirty ^%$&^* dishes!! Thanks for this enlightening hub, SteveoMc. I don't usually read product hubs, but this one got my attention since my dishwasher is about to kick the bucket. 'Tis a pity, really, but it's served its time.

LillyGrillzit profile image

LillyGrillzit 6 years ago from The River Valley, Arkansas

You are the Appliance Guru, and if they could speak, I am sure they would say Thank You SteveoMc, cause these humans don't have a clue... LOL!

SteveoMc profile image

SteveoMc 6 years ago from Pacific NorthWest Author

justom I agree, I have to rinse first, but then you can hold the load and it does the rest. Thanks for the comment.

SteveoMc profile image

SteveoMc 6 years ago from Pacific NorthWest Author

allpurposeguru Agreed once again....some of the detergents claim that if you rinse first, you risk etching some glass and ceramic wear, but I'm with you, thanks.

SteveoMc profile image

SteveoMc 6 years ago from Pacific NorthWest Author

drbj LOL you are too funny, I love you more each time I see you .....thanks for coming by and leaving such a memorable comment. I agree, keep the real dishes to the minimum....I do like the chopstick option.

SteveoMc profile image

SteveoMc 6 years ago from Pacific NorthWest Author

lorlie thanks for reading it....this is really not a product hub, but more like an informational hub, it will lead to a couple of other hubs detailing simple repairs. I try to do introductions like this for each appliance I write about. Hopefully, it will turn into an anthology of appliances and if you find one, then you can find all of them. I do like the cussing's kind of a turn on.

SteveoMc profile image

SteveoMc 6 years ago from Pacific NorthWest Author

Lilligrillzit If someone is willing to grill, then someone must do the dishes. It may as well be a machine. Thanks for the comment and for dropping by.

prolix1001 5 years ago

I love reading through your blog, I wanted to leave a little comment to support you and wish you a good continuation. Wishing you the best of luck for all your blogging efforts.

Commercial Dishwasher

Radwan Badawi 16 months ago

When we wash dishes or glasses by hand without A dishwasher , sometimes some soap stays in the glass and does not rinse off completely. Is the dishwasher better than hand washing as far as removing all soap, and what setting is best in removing the residual soap? Thank you

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