How is scale formed in an electric kettle?

Electric kettle is a common electrical appliance in many households, providing hot water conveniently and quickly. However, many users will find a layer of white or gray sediment on the bottom of the kettle or the heating element when using the electric kettle. This is what we often call scale. So, how is scale formed in an electric kettle?

1. The main components of scale are calcium carbonate (CaCO₃) and magnesium carbonate (MgCO₃), which are deposits of minerals in water. When water contains a high concentration of calcium ions and magnesium ions, this water is called "hard water". During the heating process of hard water, these minerals will undergo chemical reactions and deposit on the bottom of the kettle and the surface of the heating element to form scale.
The formation of scale is closely related to the hardness of water. The higher the hardness of the water, the more calcium and magnesium ions it contains, and the faster the scale forms. In the process of using an electric kettle to heat water, the increase in water temperature will trigger a decomposition reaction of the bicarbonate dissolved in the water, generating insoluble calcium carbonate and magnesium carbonate, which are deposited on the heating element or the bottom of the kettle. This is why after using the electric kettle for a period of time, you often see a layer of white sediment on the bottom of the kettle or the heating tube.

2. The effects of scale on the electric kettle are as follows.
Decreased heating efficiency: Scale will cover the heating element and affect its heat conduction efficiency. Since the thermal conductivity of scale is far inferior to that of metal, the heating time will be longer and the power consumption will increase.
Shortened equipment life: Scale that has not been cleaned for a long time may cause the heating element to overheat, thereby damaging the circuit or heating function of the kettle, thereby shortening the service life of the electric kettle.
Impact of water quality: Scale will also cause changes in water quality, and the boiled water may have an odor or be unclear. Especially when there is too much magnesium and calcium deposition, the taste of drinking water may also be affected.

3. How to prevent and remove scale
Regular cleaning: Regular removal of scale is the key to keeping the electric kettle working properly. Common cleaning methods include using white vinegar, lemon juice or special descaling agents. Mix white vinegar and water in a 1:1 ratio, pour it into the kettle to heat, let it stand for a while, pour it out, and then rinse it with clean water to effectively remove scale.
Use soft water: If the water quality in your area is hard, it is recommended to use soft water or filtered water, which can greatly reduce the formation of scale. In addition, installing a household water softener is also an effective measure to reduce the mineral content in the water and slow down the speed of scale deposition.
Control the heating temperature: Using an electric kettle with a temperature adjustment function, you can choose a lower heating temperature according to actual needs to avoid overheating of water and reduce the formation of scale.