Water level indicator
A device that allows you to estimate the amount of water in the kettle without opening its lid. Most often
the water level indicator has the form of a scale applied either to the transparent wall of the container, or to a transparent insert in an opaque wall. In any case, this function allows you to measure the volume of filled water quite accurately, and not just determine it “by eye”. This possibility is especially important for models with open coils (see "Heating element"), in such devices, a mark on the indicator is usually applied to the minimum allowable water level.
Thermostat
A device that allows you to set the temperature to which the water will be heated — the
thermostat monitors the temperature and automatically turns off the heating when the desired value is reached. In fact, water heated in a kettle does not always need to be boiled: for example, for brewing some types of tea, the optimum temperature is about 80 °C, and for preparing baby food — 60 °C. Thermopot are most often equipped with a thermostat, but there are also classic electric kettles with such a function.
Maintaining t° (kettle)
The ability to operate a classic kettle (see "Type") in the mode of
maintaining the water temperature — when the heated water is kept hot due to the operation of the heater at low power. For kettles, unlike thermopots, this mode is far from necessary, so its presence is indicated separately in the specs.
Thermometer
A device that displays the temperature of the water in the kettle. The presence of a
thermometer is useful if the water needs to be heated to a certain temperature. However, the thermometer does not automatically turn off the kettle, unlike a thermostat — this must be done manually. Also, the thermometer allows you to assess how much the heated water has cooled over time and whether it can be used without heating again.
Opening the lid with a button
Kettles (see "Type") in which the lid opens at the touch of a button. This opening is faster and more convenient, and often safer than the traditional way (grab the lid and pull it up): the lid can get quite hot when the kettle is in operation, and long contact with it is fraught with burns. And although the button can also be placed on the lid, a short press is enough to activate it, and even in such cases the risk of getting burned is minimal. On the other hand,
opening the lid with a button complicates the design of the kettle and reduces its reliability.
Limescale filter
Small removable mesh, usually located at the spout, that traps lime scale particles when pouring water. The filter is easy to remove for cleaning and prevents scale from entering the cup.
Display
The own
display noticeably simplifies and facilitates the use of the kettle. Most often, this is the simplest single-colour screen, capable of displaying 2 — 3 figures and possibly the individual special symbols — however, in this case, more is not required. The display is especially convenient when selecting and controlling the heating temperature — after all, it is much more convenient to navigate by specific numbers than by simpler devices like colour indicators. Actually, the presence of a screen almost 100% guarantees that this model is also equipped with a thermostat.