Comparison Hotpoint-Ariston VLS EVO 100 EU vs Hotpoint-Ariston ABS VLS EVO PW 100

The presence of 2 water tanks in the storage water heater; usually, the total volume is divided equally between these tanks.

This design is noticeably more complex and expensive than the traditional 1-tank arrangement but offers several advantages. Firstly, the tanks can be heated in turn, which significantly speeds up the process. After all, for hot water to be used, it is enough to warm up only half of the total volume to the operating temperature. Secondly, with this format of work, power consumption and the load on the power grid are reduced. And if at a certain moment, the user does not need a lot of water, then the energy consumption turns out to be small (again, because the entire volume does not need to be heated). Thirdly, compared to traditional models of the same volume, such boilers are thinner, which can simplify installation (the price for this advantage is an increase in width, but this moment is not so often critical). Fourth, this arrangement improves thermal insulation and reduces heat loss.

The shape of the water heater.

The traditional options are cylindrical and rectangular, but nowadays there are more specific options — flat cases, slim cylindrical devices. Here are the features of each of these options:

— Cylindrical. This form is traditional for storage water heaters. It is because with the same total volume, less material is needed for a cylindrical tank than for a rectangular one; and in production, such tanks are simple and cheap, which allows them to be used in water heaters of any price category. The disadvantages of this form include, first of all, some bulkiness in comparison with other options.

— Rectangular. The case is rectangular in shape, with pronounced front and side faces; the corners can be both sharply defined and rounded. It is the traditional form for instant water heaters, primarily gas, but it can be found in a fairly large number of storage models. Accordingly, the features of a rectangular case will be different — depending on the type of heater. So, in instant water heaters, the “rectangle” is simply one of the most convenient options in terms of the overall layout. But in storage water heaters, this shape differs from the flat one (see below) only with a slightly greater thickness and, in some cases, pronounced angles.

— Flat. A variant found mainly in s...torage electric heaters. Such devices look as if the classic cylindrical body was flattened at the back and front, reducing its thickness by increasing the width (and sometimes height). Thus, such a boiler does not protrude as much in front of the wall as a cylindrical one; in some cases, this point may be fundamental — for example, when installed in a bathroom, where a cylindrical device would hang over the toilet bowl, creating discomfort.

— Slim. A variety of cylindrical cases are characterized by a reduced diameter. In other words, boilers from this category are also round, but with the same volume, they have a noticeably smaller width and thickness than traditional cylindrical ones. In cramped conditions, this can be very useful. However, it must be borne in mind that the price for reducing the diameter is an increase in height.

Electrical power consumed by the heater during operation.

This parameter is of key importance for electric models (see "Energy source"). In them, the power consumption corresponds to the power of the heating element and, accordingly, the heat output of the entire device. The overall efficiency and flow rate of the water heater directly depend on the useful power. Accordingly, high-flow rate models inevitably have high consumption. At the same time, we note that the heating power is selected by the designers in such a way as to guarantee the necessary flow rate and water temperature. So when choosing a device according to flow rate, you need to look primarily at flow rate and temperature. Power must be taken into account when connecting: for example, if a 220 V model (see "Power source") consumes more than 3.5 kW, it, as a rule, cannot be plugged into a regular outlet — connection is required according to special rules. And the most productive and high-powered models — 10 kW or more — are connected only to three-phase mains.

The power consumption has a similar value for combined boilers — adjusted for the fact that in them the electric heater is an additional source of heat. For gas and indirect models, this parameter describes the power consumption of control circuits and other auxiliary structural elements; this power consumption is usually very small — on the order of several tens of watts, less often up to 1.5 kW.

The number of heating modes provided in the device.

This parameter is specified only for models with several heating modes. We emphasize that you should not confuse such functionality with temperature control (see "Features"). The heating mode is the general format of the device; these formats differ primarily in such parameters as the actual heating power, the number (and in combined models, and types) of the heating elements involved, etc. The thermostat, if it is in the design, allows you to change the temperature within a specific mode.

In general, the presence of several heating modes expands the functionality of the water heater but affects its cost. Of course, the specific features of these modes do not hurt to clarify in advance before buying.

The highest water temperature provided by the device. The standard temperature of hot water in the water supply is 60 °C, and this value is actually the minimum for modern water heaters: models with more modest rates (usually from 40 °C) are extremely rare. But higher values can be found much more often: for example, water heaters of 75 °C and 80 °C are very popular, and in the most powerful models in this regard, the temperature can reach 95 °C and even higher.

On the one hand, strong heating requires appropriate power (which is especially noticeable in the case of instant electric heaters). On the other hand, the higher the temperature of hot water, the less it is needed for a comfortable outlet temperature, after mixing with cold water; this reduces the consumption of heated water, which is especially important for storage boilers. In addition, many models have thermostats (see "Features").

Also, note that heating to operating values may involve different ΔT (degree of temperature change) — depending on the initial temperature of the cold water. The actual performance of the heater directly depends on ΔT; this moment is described in more detail below, in the paragraphs devoted to performance at different ΔT.

Among the functions of the water heater there are thermostat, water flow regulator, Smart (auto mode), programmer, display and control via the Internet. More about each of them

— Thermostat. A device that allows you to control the temperature of the water at the outlet of the heater. In storage models (see "Type"), the thermostat sets the maximum temperature for heating water in the tank; in instant devices, this function is carried out by changing the intensity of heating.

— Automatic water flow regulator. It is used in instant water heaters. Since the water in such devices heats up in the process of its movement through the heater, the higher the speed of water movement (the greater the pressure), the lower the heating temperature, and if the pressure is too high, the power of the device may simply not be enough for effective heating. The use of an automatic water flow regulator avoids this — this system regulates the speed of water movement through the heater, limiting it if necessary.

— Smart (auto mode). A special “smart” mode in which the boiler is controlled (primarily the intensity of heating) automatically. Specific features of this mode may vary depending on the model. However, the following format of operation is most common: during...the first week of use, the device remembers at what time of the day the hot water was used, and then the heater’s operating mode adjusts to this data. Thus, the water heater provides the user with hot water at the right time and, at the same time, does not waste energy on heating during hours when heating is not needed.

— Programmer. The presence of a programmable thermostat — a device that allows not only to maintain the temperature but also to programme the operation of the device for a certain period. The simplest programmers work like a timer, turning on at the right time (vacation or holiday mode, when the device is not active for several days, and when the family returns to the house, it will turn on and heat the water). More advanced ones allow you to set the mode of operation for individual days. Either way, this feature provides added convenience and eliminates the need to constantly adjust the operation of the device manually. On the other hand, the presence of a programmer affects the cost.

— Display. Usually, a simple LCD screen with a few characters is used as a display. However, even such equipment significantly increases the convenience and information content of management. Various service data can be shown on the display — from the temperature of the water in the tank to messages about malfunctions and failures. This feature slightly increases the cost of the device, but compared to the total cost of the heater, this moment is usually insignificant.

— Control via the Internet. The specific nuances of such control may vary: for example, some models use a special application installed on a smartphone or tablet, while others can work through a regular browser from any computer. However, this function allows you to control the heater from almost anywhere in the world — provided that there is access to the Internet. In addition, with this control, the user can also monitor the status of the device and receive various notifications (on and off, about the temperature of the water in the tank, about various problems, etc.).

The safety of water heaters can be carried out by such functions as overheat protection frost protection, dry heating protection, surge protection, electrical protection (RCD), anti-legionella, gas control and draft sensor. More about them:

— Overheat protection. Water heater safety system that automatically turns off the power supply or gas supply (depending on the type) when the heating element reaches a critical temperature. It avoids overheating and the troubles associated with it, ranging from heater failure to fire.

— Frost protection. Function to prevent freezing of water in the circuits, tank and/or heat exchanger of the water heater. It will be useful when the device is installed in a room with a low temperature and works with long breaks. Frozen water expands, which can damage the device; to avoid this, the frost protection monitors the temperature of the water in the device and turns on the heating when this temperature drops to a critical level.

— Dry heating protection. A safety system that prevents the heater from being switched on without the presence of water in it. Since the heating element does not transfer heat to the water when turned on, it heats up very q...uickly and, in a short time, reaches a high temperature that can lead to damage to the heater and even to a fire. The presence of protection against switching on without water allows you to avoid such unpleasant consequences.

— Voltage surge protection. System for protecting the heater from power surges. Electronically controlled models are usually equipped with such protection (see Control) since it is the control electronics that are most sensitive to problems with the power supply. Note that the capabilities of such systems are noticeably more modest than those of specialized stabilizers or protective systems: the “hardware” of a water heater can smooth out relatively weak power surges, but in case of serious failures, it will most likely simply turn off the device to avoid damage. However, this feature will be useful; except that in very unstable electrical grids, prone to frequent fluctuations, such a heater may require an external stabilizer.

— Electrical protection (RCD). Built directly into the heater, the RCD is a residual current device. Such a device is primarily intended to protect people from electric shock — for example, if the insulation is damaged and electricity leaks into the case or water. When a person comes into contact with this electricity, a so-called leakage current occurs. The RCD reacts to it and almost instantly turns off the power to the boiler, preventing electric shock.
Note that such safety devices are standardly installed directly in switchboards. However, the presence of an RCD in the water heater provides additional security. Naturally, such equipment is found mainly in electric models.

— Safety valve. A safety system that prevents a critical increase in water pressure in the heater. Usually, this protection is based on a safety valve that opens when a certain pressure level is reached and drains excess water, avoiding damage to the heater.

— Gas control. Gas heater safety system that automatically shuts off the gas supply in the event of a burner flame failure. It avoids filling the room with gas and possible unpleasant, and even tragic consequences. Resuming the gas supply after the protection is triggered must be done manually.

— Draft sensor. A sensor that monitors the presence of draft in the flue of a gas water heater. This function is especially important for models with open combustion chambers: in the absence of a draft, combustion products will fill the room where the heater is located. And this, in turn, can lead to a deterioration in people's well-being, health problems and even deaths. To avoid such consequences, this sensor, when detecting problems with the draft, turns off the gas supply and issues a warning about the problem. However, such equipment can also be found in models with closed combustion chambers. In them, the draft sensor performs mainly a diagnostic function, allowing you to determine what interferes with the normal operation of the burner.

— Anti-legionella. A function that prevents the growth of pathogenic bacteria in the tank and water heater circuits. Some types of such bacteria can live and multiply in fairly hot water — up to 60 °C. To avoid this, the anti-legionella system monitors the temperature of the water in the tank and periodically raises it to a level of about 65 °C. The specific methods of operation of such systems can be different: for example, some work strictly according to a set schedule (for example, once every two weeks), others turn on additional heating only if for some period (for example, a month) the water has not been heated to sufficiently high temperatures.

The direction from which pipes are connected to the heater. The choice for this parameter depends primarily on the characteristics of the place where the device is planned to be placed. Note that in universal models (see "Installation"), the place of connection of pipes depends on the method of installation, while specific options in different models may be different, this should be specified separately.

The weight of the device, excluding the water collected (passing) into it.