A dishwasher is one of modern technology's best fix-it and forget-it appliances. You load dirty dishes inside, add some soap, turn it on and ta-da! In about an hour, your dishes are clean again! The dishwasher was actually invented by Josephine Cochrane in 1887 when the servants who were supposed to be washing her dishes kept chipping the china. Josephine came up with a simple hand-powered dishwasher. This idea was taken and improved upon by William Liven in 1924, who added water-propelled spraying arms and heating elements to the design. Thus, the modern dishwasher was born. ... But how does it work? Getting to know how your dishwasher operates can help you know how to clean and maintain it, which is especially important if you have a home repair warranty!
A dishwasher is actually a relatively simple device when it comes to kitchen appliances. It has a few main parts, including the dish racks, spray arms, float valve, fill valve, heating element and the fill dispenser. Here is what a real dishwasher looks like on the inside:
Although there are a number of different models for heating elements, filters and the location of the spray arms, dishwashers all generally have these same (or similar) parts. These parts (and how they work) haven't changed much since the 1940's when the dishwasher first became popular.
A dishwasher has five steps it goes through when getting your dishes cleaned.
After loading your dirty dishes, putting in soap and selecting the correct cycle, the bottom basin of your dishwasher begins to fill with water. This water is warmed with the heating element to about 130 degrees Fahrenheit. The float in the bottom of the basin makes sure that the basin doesn't overflow. If your dishwasher does overflow, this float could be malfunctioning, which can be repaired with a home warranty. If the water reaches a certain point, the float will rise to that water level and shut the fill valve off. Once the water reaches the right temperature (hot enough to get stubborn, stuck-on food off of dishes) it will be sprayed onto the dishes. If the water isn't warm, it could be the heating element malfunctioning, which can be replaced and covered by a home repair warranty.
- Pumping and Spraying
A pump will take the heated water from the basin of the dishwasher and into the spray arms. Here the water is forced through small holes in the spray arms at high pressure, spraying warm water onto the dishes. The motor does not cause the arms to rotate; the motion is actually caused by the high water pressure forced out of the spray arm. This water is used again and again as it falls back to the basin of the dishwasher, and is pumped through the spray arm again. (If this pump has been damaged, or the motor burned out, the proper home repair warranty can repair or replace it for a service call fee if it's failed from normal wear and tear.) The highly pressurized water sprays onto the dishes, getting rid of stuck on food. This food is washed into a filter so it won't get reused and pumped into a spray arm. However, if you don't properly clean your dishwasher, food can still get pumped into a dishwasher's spray arms, reducing the effectiveness of the dishwasher. This is why it is extremely important to maintain and clean your filter often. This maintenance is especially important if your have a home repair warranty. If you have a home repair warranty that covers your dishwasher and it fails, it needs to be properly maintained to receive the best coverage.
- Cleaning with Detergent
Depending on the cycle you selected, after a few rotations of the spray arms, a computer will open the detergent dispenser. The soap you have placed into the dishwasher will fall out and mix with the water, adding extra cleaning power. Remember to not use anything but dishwasher-approved detergents "“ using dish soap can cause suds to overflow onto your kitchen floor. Also, if you are using a tablet detergent, you should place it in the pre-rinse part of the dishwasher. Most tablets include prewash that will dissolve first. As a home repair warranty company, Landmark also advises in not putting too much detergent into the washer, as it can scratch your glassware.
- Rinsing and draining
The spray arms will continue to spray water that is being warmed by the basin's heating element. This water will rinse off of the detergent and any leftover food that is on the dishes. After the cycle is over, the dirty dishwater is drained by a pump out of the drain line. Sometimes this dirty water is pumped to the sink's drain line.
- Dry cycle
This is an optional cycle, but many dishwashers complete it by using the heating element in the basin of the dishwasher. The heating element raises the temperature in the dishwasher to turn the remaining water into steam, which is then vented out of the appliance. If your dishes aren't drying, and there is a lot of moisture left on them after a cleaning cycle, your heating element could be broken. This can be repaired or replaced if the dishwasher is included in your home repair warranty.
That's how your dishwasher works! If you're interested in maintaining and repairing your dishwasher, take a look at our previous post. This is important information for any of our home repair warranty holders. If you don't have a home repair warranty, but you want your systems and appliances covered, take some time to learn more about Landmark Home Warranty.