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.
Min. heat output
The minimum heat output at which the heating boiler can operate in constant mode. Operation at minimum power allows you to reduce the number of on-and-off cycles that adversely affect the durability of heating boilers.
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:
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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).
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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.
Coolant min. T
The minimum operating temperature of the heat medium in the boiler system when operating in heating mode.
"Summer" mode
It is an operating mode designed for the warm season. In this mode, it works only to provide domestic hot water, and the heating is turned off. If the boiler is equipped with an outside temperature sensor, this sensor is also switched off in
summer mode so that the heating does not turn on at night when the outside temperature drops.
Expansion vessel capacity
The capacity of the expansion tank supplied with the boiler.
The expansion tank is designed to drain excess water from the heating system when the total volume of liquid increases as a result of heating. It consists of two parts connected by a flexible membrane: in one, hermetically closed, there is air under pressure; in the other, excess water enters, compressing the membrane. In this way, a catastrophic increase in pressure in the heating circuit is avoided. The optimal volume of the expansion tank depends on several system parameters, primarily the volume and composition of the coolant; detailed recommendations for calculations can be found in special sources.
Safety systems
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Gas pressure drop. This protection system ensures that the boiler is switched off in the event of a critical drop in gas pressure, insufficient for the normal functioning of the burner. In the event of such a fall, the valve that supplies gas to the burner is closed and blocked. After the restoration of gas pressure, it also remains closed; it is necessary to open it and resume the gas supply manually.
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Water overheating. A temperature sensor automatically turns off the boiler when the temperature of the water in the system is critically exceeded.
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Flame loss. Flame loss protection is based on a sensor that monitors the combustion of gas and automatically stops its supply. It prevents the room from filling with gas and the possible tragic consequences of this.
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Draft control. In boilers with an open combustion chamber, to maintain normal conditions in the room where such a boiler is installed, constant removal of products of combustion into the atmosphere is necessary. The lack of a normal draft in the chimney can lead to the accumulation of combustion products in the room. The draft protection system prevents this by automatically turning off the boiler when it detects the release of combustion products outside the chimney.
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Power outage. Most modern boilers h
...ave an electronic control system; in addition, many structural elements (pumps, valves, fans, etc.) are also powered by electricity. Thus, a power outage during the operation of the boiler will inevitably lead to an abnormal mode of operation, which is fraught with breakdowns and even accidents. To prevent such cases, a power outage protection system is installed, which completely stops the operation of the boiler in the event of a power outage. When the power supply is restored, the boiler needs to be restarted manually.
— Water circulation failure. This protection system controls the normal movement of the water through the heating circuit. Water circulation failure can lead to overheating of some elements of the boiler and damage to it. To avoid this, if the circulation is disturbed, the system turns off the pump and shuts off the gas supply to the burner.
— Frost protection. A system that controls the temperature in the heating circuit. Freezing of the liquid in the circuit disrupts the normal operation of the heating, which may require heating of the pipes and lead to system damage. To avoid this, when the water temperature drops below 5 °C, the burner is ignited, the circulation pump is activated, and the circuit warms up to a temperature of about 35 °C — thus preventing the formation of ice in the pipes.
