Heating area
The maximum area of the building that the boiler can effectively heat. However, it is worth considering that different buildings have different thermal insulation properties and modern buildings are much “warmer” than 30-year-old and even more so 50-year-old houses. Accordingly, this paragraph is more of a reference nature and does not allow a full assessment of the actual heated area. There is a formula by which you can derive the maximum heating area, knowing the useful power of the boiler and the climatic conditions in which it will be used; see Heat output for more details. In our case, the heating area is calculated according to the formula "boiler power multiplied by 8", which is approximately equivalent to use in houses that are more than a dozen years old.
Heat output
It is the maximum useful power of the boiler.
The ability of the device to heat a room of a particular area directly depends on this parameter; by power, you can approximately determine the heating area, if this parameter is not indicated in the specs. The most general rule says that for a dwelling with a ceiling height of 2.5 – 3 m, at least 100 W of heat power is needed to heat 1 m2 of area. There are also more detailed calculation methods that take into account specific factors: the climatic zone, heat gain from the outside, design features of the heating system, etc.; they are described in detail in special sources. Also note that in dual-circuit boilers (see "Type"), part of the heat generated is used to heat water for the hot water supply; this must be taken into account when evaluating the output power.
It is believed that boilers with a power of more than 30 kW must be installed in separate rooms (boiler rooms).
Power supply
The type of electrical supply required for normal operation of the boiler. Power supply may be required not only for electric models but also for other types of boilers (see "Power supply") — in particular, for the operation of control automation. Connection options can be:
—
230 V. Work from a household system with a voltage of 230 V. At the same time, models with a power consumption of up to 3.5 kW can be connected to a standard outlet, but for high consumption devices, you need to connect directly to the distribution board. Many of the electric boilers with this connection also allow operation from 400 V (see below).
—
400 V. Operation from a three-phase system with a voltage of 400 V. This power supply is suitable for boilers with any power consumption. However, it is not as common as 230 V: in particular, it may be difficult to use it in a residential area. Therefore, this option is provided mainly in high-power devices for which a 230 V power supply is not suitable.
— Autonomous work. Work in completely autonomous mode, without an electricity connection. This format of operation is found in all boilers that do not use electrical heating (see "Energy source"), except for purely liquid fuel ones — in them, electricity is necessary for the operation of the fuel supply systems.
Power consumption
The maximum electrical power consumed by the boiler during operation. For non-electric models (see Energy source), this power is usually low, as it is required mainly for control circuits and it can be ignored. Regarding electric boilers, it is worth noting that the power consumption in them is most often somewhat higher than the useful one since part of the energy is inevitably dissipated and not used for heating. Accordingly, the ratio of useful and consumed power can be used to evaluate the efficiency of such a boiler.
Coolant min. T
The minimum operating temperature of the heat medium in the boiler system when operating in heating mode.
Coolant max. T
The maximum operating temperature of the heat medium in the boiler system when operating in heating mode.
Heating circuit max. pressure
The maximum pressure in the heating circuit of the boiler, at which it remains operational, and there is no risk of physical damage to the structure. For a heating system, the maximum pressure is usually about 3 bar, and for a domestic hot water circuit up to 10 bar. When the maximum pressure is exceeded, a safety valve is activated, and part of the water is discharged from the system until a normal pressure level is reached.
Outdoor temperature sensor
The outdoor temperature sensor allows you to monitor the outdoor weather conditions and automatically adjust the operation of the boiler to them — increase the heating power when the outside temperature drops and decrease it when it rises.
Heated floor mode
The boiler has a special
mode for underfloor heating systems.
Underfloor heating differs from conventional heating systems primarily by a
lower coolant temperature — otherwise the floor could be too hot for comfortable use (plus, high temperatures are also undesirable for flooring and furniture installed on it). In addition, boilers with this function are distinguished by increased pump power. In order to ensure efficient circulation of the coolant through branched heating circuits that have rather high resistance.
