A kettle element is the part of an electric kettle that actually turns electrical current into heat, thereby heating the water in the kettle. The element is generally located at the bottom of a kettle. Some kettles employ elements that resemble tubes and run through the lower part of the vessel. Other designs make use of flat plate elements that directly heat the bottom of a kettle. Both types of element may eventually fail and can require periodic cleaning and simple maintenance.
Electricity is used to generate heat by passing an electrical current through a resistor. A resistor allows the passage of an electric current, but as its name implies, impedes the smooth flow of current. When electrical current is forced to overcome resistance, some portion of the energy of the electrical current is released in the form of heat. In an electric kettle, a current is run through a kettle element, which is essentially a large resistor, and this process generates the heat needed to raise the temperature of water.
The best results are obtained when a kettle element is located at the bottom of an electric kettle. Water, when heated, rises. Heating elements that are located at the bottom of a kettle will heat the water that they are in contact with. This water will then rise and a convection current will form, bringing cooler water down to be heated, and ensuring the even heating of a kettle full of water.
Kettle elements come in two basic varieties, tubular and flat. Tubular elements run directly through the water in the kettle, although they are sealed so that the electrical current cannot flow through the water in the kettle. Flat elements generally consist of a coiled resistor that is attached to the underside of a plate at the bottom of the kettle. These elements heat the plate, which then transfers heat to the water in the kettle.
Resistors are very durable and fail quite rarely. The resistors in a kettle element, however, can fail after a prolonged period of use or as a result of damage to the unit. One of the most common causes of kettle element failure is impact damage, which may break the resistor or damage the connections on either end of the resistor, preventing the current from properly flowing through the element.
Elements in electric kettles typically require a small amount of routine cleaning and maintenance. Mineral deposits often build up on heating elements. This is unsightly and also impedes the smooth functioning of the element, as the mineral deposits impede heat transfer. Deposits are most pronounced when the water used in a kettle is very hard. Gentle cleaning with a cloth and white vinegar will remove most mineral deposits.