The functions of the tap are mainly design features, among which the are
check valve,
bottom valve,
cold start,
LED backlight,
temperature adjustment lever,
display,
auto-drain (hygienic flush),
washer/dishwasher switch< /a>, shelves for accessories. In more detail:
— Check valve. The non-return valve prevents the flow of water through the tap in the opposite direction — for example, when there is a large pressure difference between hot and cold water. This function will be relevant for those who are going to install water metres: the presence of check valves on mixers is often a prerequisite for fulfilling an application for installation, because such valves prevent counters from spinning in the opposite direction. In addition, you should pay attention to the presence of a check valve in the tap (especially a single-lever tap, see "Tap type"), if there are interruptions in the water supply of your house — such taps behave much better in case of pressure surges in the water supply.
— Drain valve. A device that allows you to close the drain hole in the sink, kitchen sink or bidet (depending on the purpose of the tap). There are two types:
— Lever drain valve.
...To control the operation of such a valve, a small lever is used, located behind the tap, on the side of it or in front of the body. Raising and lowering it opens and closes the drain plug in the sink.
— Pressing drain valve. Valves of this type are locked and unlocked by pressing the drain plug, for which you need to wet your hand.
— Cold start. A feature found exclusively in single-lever models. The general principle of operation of the “cold start” is as follows: if you open the tap with the initial position of the joystick, it will not bring out mixed warm water (as in more traditional single-lever devices), but only cold water. To add hot water and raise the temperature, you need to deflect the lever from its initial position. Such a format of work can provide significant savings: by default, cold water comes out of the tap, and hot water is added to it only if necessary.
— LED light. Lighting system based on LEDs — an efficient and economical source of illumination. The purpose and functionality of such a backlight may be different. So, in some models, it is installed on the spout and directed downwards, which allows you to clearly see the space under the spout even in low ambient light. Sometimes such illumination also illuminates the stream of water, giving it an unusual appearance. There are also quite original systems — for example, with a transparent spout and LEDs at its base, which creates the effect of a tap glowing from the inside; and in some models, the lighting also changes color depending on the temperature of the water. However, anyway, this feature significantly affects the cost, so it is typical mainly for premium products.
— Autodrain (hygienic flush). Such a system is equipped with taps with additional electronics — mostly contactless models, as well as products with a thermostat or a button switch. The autodrain works as follows: at a certain rate (for example, once every 12 hours or once a day), the automation briefly turns on the water. Due to this, harmful bacteria are washed out of the device, which tend to multiply on the inner surfaces of the spout and in “stagnant” water inside the tap itself. At the same time, the consumption of water for hygienic washing is small, usually it is practically not noticeable against the background of general consumption.
— Temperature adjustment lever. A function found in taps, which design initially does not imply a temperature controller — primarily non-contact models, as well as in products with one main lever or with button activation (see "Tap type"). As the name implies, the temperature control lever allows you to use such a tap not only to control the pressure, but also to change the temperature of the water.
– Display. Taps that display temperature and/or current water flow. The display provides a clear visualization of the settings and allows you to see what kind of water and how much is flowing from the tap. However, the presence of the screen significantly affects the cost of the tap.
— Washer/dishwasher switch. A function that can significantly facilitate the connection of a washing machine or dishwasher to the water supply system. Taps with a washer/dishwasher switch have a separate pipe for connecting the dishwasher, as well as the switch itself, which allows you to open and close the water supply to this pipe. Thus, to connect a washing machine or dishwasher, you do not need to install additional bushings, splitters, etc. — just connect the device to an existing output. And you can control the water supply directly from the tap body, for this you do not need to get under the sink or into another hard-to-reach place.
— Shelf for accessories. Most often, the role of such a shelf is played by the upper part of the body, specially made flat. This feature is found mainly in bath and/or shower taps (see “Suitable for”): it is convenient to keep shampoos, gels, soaps and other cosmetic/hygiene products on the shelf.
Note that this function is rare — mainly in high-end taps (in particular, thermostatic ones), which initially have large body sizes. In more traditional models, it makes no sense to include this design element — it is wiser to purchase a shelf as a separate accessory for the bathroom.
