How Does a Dishwasher Work?

How dishwashers work

We all know how a dishwasher works – dishes go in dirty, and then come out clean. But what you might not realise is exactly what goes on during that process. A dishwasher is a machine that performs a series of actions to make sure your dishes get the clean, dry and shine they deserve. With the right detergent the dishwasher can run at optimal performance. The mechanisms behind all of this are simpler than you might think.


How does a dishwasher work?

Many of us argue about how to stack the dishes in the dishwasher to get the best clean, but don’t overthink it. By evenly spacing out your plates, bowls and cutlery, adding your detergent and closing the machine properly, your dishes will soon be sparkling! Once you’ve started your wash cycle its time for your dishwasher to do what its great at. During the cycle, m

  1. Add water: The water is pumped into a shallow basin at the bottom of the dishwasher, usually underneath the jet arms.
  2. Heat the water: This is done with a heating element in the basin.
  3. Add detergent: The detergent is released automatically at the correct stage of the wash by the dishwasher’s timer.
  4. Wash dishes: The heated water and detergent is pumped up through the jet arms, and the pressure causes them to spin and shoot out the water with enough force to make sure the dishes get a good clean.
  5. Drain the dirty water: To keep your dishes clean, the first load of dirty water is drained from the basin.
  6. Rinse the dishes: Clean water is added again and heated as before, releasing Jet-Dry rinse agent instead of detergent this time. This water is pumped through the jets to make sure there is no detritus or detergent left on the dishes.
  7. Drain the second load of water: Finally, the last of the dirty water is drained out of the basin.
  8. Dry the dishes: The heating element at the bottom of the dishwasher heats up the air and dries the dishes and cutlery. Your dishes are now sparkling clean and ready for use.

Of course, for your dishwasher to work as well as possible it needs to be kept clean, and free of debris and build-up. That is why regular dishwasher maintenance is essential.


How long should a dishwasher last?

Typically, most dishwashers should last at least ten years[1], but - with proper care and maintenance - many can keep going for even longer. Understanding how your dishwasher works and the parts which are most likely to become clogged and/or experience damage is key to extending its life expectancy.

There are three key features in a dishwasher which help to drive the dishwashing process:

  • Heating element
    These are pieces of metal at the bottom of the dishwasher that convert electricity into heat and heat the water to the correct temperature. As these are in direct contact with the water these are particularly prone to accumulating lime-scale over time.
  • Spray arms
    These arms are hollow and can be found in the dishwasher basin and below the top drawer. The pressure of the water being pushed through the arms causes them to spin, ensuring that all dishes get an even clean. Food, grease, and other dirt can block these jets over time, so it is important to keep these clean.
  • Pump
    The pump is a motor found under the spray arms that either forces the water through the jets during the clean, or to the drain during the draining process. The dishwasher opens and closes the valves at the right time to make sure the water goes in the right direction.

Monthly use of Finish Dishwasher Cleaner helps remove any lime-scale that accumulates, as well as the other food and grease residue that can clog up hidden parts. With the appropriate amount of care, your dishwasher can keep it working at its best condition.