The heating element, a small, tube-shaped device used in modern-day dishwashers plays a critical role in the function of a dishwasher. While the actual water heater is responsible for heating water before it enters the dishwasher, the heating element is a supplemental tool that serves several different purposes.
When dirty dishes sit in the sink for long periods of time, they tend to develop a layer of bacteria-ridden biofilm. It’s not uncommon for salmonella, E. coli and other harmful bacteria to form on this layer. The good news is that you can still use your dishes after they develop this film, assuming you wash them in water that’s hot enough to kill the bacteria
According to an article published by TheAtlantic, water that’s heated to 145 degrees Fahrenheit will “easily and quickly” kill bacteria. The author also points out that most modern-day dishwashers operate at a temperature between 130 to 170 degrees Fahrenheit.
Water entering the dishwasher has an average temperature of 120 degrees Fahrenheit, which may or may not properly sanitize the dishes. The heating element, however, warms the water up by an additional 10-15 degrees; thus, effectively killing harmful bacteria and germs.
While the exact method of operation varies depending on the dishwasher’s design, most modern-day models feature a heavy-gauge wire with a ceramic coating that’s attached to a couple different brackets. As the electrical current passes through it, the wire generates heat. These elements are typically exposed at the bottom of the dishwasher tub.
In addition to killing bacteria, the dishwasher’s heating element serves a second purpose: to encourage faster and more efficient drying times. Ever notice how the “low-heat” setting on your clothes dryer takes longer to dry your clothes? Well, this same principle holds true for the dishwasher. Heat encourages moisture to evaporate, leaving your dishes nice and dry. If you wash a load of dishes on the “heated” setting, the heating element will warm the unit’s internal temperature to assist in drying.
Some brands, like Bosch, will not have an exposed heating element. They will use an in-line heater. Like exposed heating elements, the in-line heater will increase the temperature of the inbound water to reach sanitize temperatures. These elements do NOT assist with the drying process.