With the development of private housing construction, serious difficulties emerged with the lack of possibility of connecting centralized heating and hot water networks to some areas.
The problem is not so much the long distances as the deterioration of the highways and their full load, which does not allow the connection of new subscribers.
In addition, housing and communal services tariffs do not suit many users and force them to look for new ways to resolve the issue.
The optimal way is to create an autonomous heating system using a gas boiler as a source of thermal energy.
Let's consider the units of one of the most famous European companies - the Italian company Ferroli.
Ferroli double-circuit gas boilers
Ferroli is an Italian company founded in 1955 and managed to develop from a small workshop into a powerful manufacturing concern of global importance.
One of its activities is the production of gas heating boilers, manufactured using the most advanced technological methods . Double-circuit units have the most complete functionality - they provide heating for the house in parallel with the preparation of hot water for domestic needs.
They are compact, economical and highly efficient. Ferroli constantly conducts scientific and technical research to improve the quality and reliability of its products.
The result was the opportunity to significantly reduce the price of boilers with a slight limitation of functionality, which did not affect performance, but significantly increased demand.
Immergas
Immergas is one of the leaders in the market of heating devices for public and domestic premises. The company's headquarters have been located in the Italian city of Brescello since 1964. Immergaz boilers are represented in more than 32 countries around the world. The manufacturer is constantly improving its products and expanding its supply boundaries.
The manufacturer has a personal development and research center engaged in the design and manufacture of all types of heating structures. All products comply with the standards of each country where supplies are made.
Construction of the Immergas ZEUS Superior gas boiler
SeriesCharacteristics
| Immergas ZEUS Superior | Models in this series are mounted Italian boilers with a closed combustion chamber, having two circuits. The power of Immergas ZEUS Superior units is 24, 30, 34 kW. The average power factor of all boilers is 94%. The Immergas boiler operates at a minimum gas pressure of 3.5 mbar. The models do not require a voltage stabilizer, nor does it require observing polarity when connecting the unit to electricity. By replacing the injectors, it is possible to switch to liquefied gas. The kit includes a smoke removal pipe, a room thermostat, a special filter for hot water, a heating filter + pressure gauge + cleaning tap, and an anti-scale magnet. |
| Immergas NIKE Star | This is a wall-mounted gas heating boiler with a magnet for water preparation, a filter for hot water supply, a heating filter and a room thermostat. The series has two circuits, an open combustion chamber. Smoke is removed from the system forcibly. Combined heat exchanger, made of copper. The efficiency reaches 91.1%. It has an electronic board with a microprocessor, electric ignition and electronic flame modulation. The system has autodiagnostics. Can operate at very low gas pressure (3 mbar). It is possible to convert the boiler to liquefied gas. |
Gas boilers require regular maintenance.
Advantages and disadvantages
The advantages of Ferroli double-circuit boilers should be considered:
- High quality parts, elements and assemblies manufactured using modern technologies.
- Full functionality of boilers that allows you to heat rooms and provide them with hot water.
- Economical, relatively low gas consumption.
- Stability, stable operating mode.
- Availability of several types of design and functionality of units.
- Wide choice of power.
- Ease of Management.
- Availability of a self-diagnosis system.
- Compact, small size.
- Attractive appearance of the units.
The disadvantages of Ferroli double-circuit boilers are:
- Energy dependence. The need to use a voltage stabilizer and correctly connect the phase electrode. Mandatory grounding.
- Excessively high sensitivity of the electronics, often leading to failure of the expensive control board.
- A combined (bithermal) heat exchanger installed on some models requires the use of softening water filters; replacing it costs almost half the cost of the boiler.
Most of the shortcomings are not an exclusive feature of Ferroli double-circuit boilers and apply equally to all similar models from any manufacturer.
Although this does not reduce their negative value, such shortcomings should be treated as design costs.
IMPORTANT!
You can avoid harmful consequences by installing a voltage stabilizer and a softening water filter. This must be done from the first days of operation of the boiler. As a result, breakdowns and failure of the electronics and heat exchanger can be eliminated.
About the manufacturer
The Ferroli brand belongs to the Ferroli Group, which has been producing gas heating boilers, water heaters and indirect heating boilers since the 50s of the last century. In Russia there is an official representative office in the form of FerroliRus LLC, and products are also distributed through official dealers located in almost every region. During its activities in the Russian Federation, the company has established itself as a manufacturer of extremely affordable, high-tech gas boilers with very serious technical characteristics, comparable to more expensive German and Japanese models. However, in the last decade, boiler reliability has been unpredictable.
The device is based on the example of the Ferroli Domina F 32 N model. Quite a typical and most effective design for today, modulating burner, built-in expansion tank. Excellent layout and assembly.
In practice, all, even the most budget models, have an efficiency of 91-93% and, accordingly, some of the best gas consumption indicators. For example, the maximum natural gas consumption of the 24 kW Fortuna model is 2.72 m3/hour, which corresponds to the well-known economical Baxi, Buderus or Viessmann. All floor-standing models come with a durable, corrosion-resistant cast iron heat exchanger, and some wall-mounted models come with a copper heat exchanger. The controls are intuitive; all models have the ability to connect external controls.
Double-circuit models are distinguished by the technology of preheating the secondary DHW heat exchanger, which reduces the delay in the supply of hot water. All boilers are equipped with an almost complete set of protective functions available today: self-diagnosis, protection against freezing, overheating, stopping the circulation pump, etc. Some models can be connected to solar panels.
All models have a minimalistic, stylish design and a minimum of communications around, which allows you to successfully place the boiler in almost any interior.
However, despite their popularity, high performance and functionality, we do not recommend wall-mounted models. It is worth thinking carefully about whether it is worth choosing floor Ferroli. It's all about reliability, namely, a large number of problems with installation practices and complaints on forums; in terms of the number of service calls, gas Ferroli are among the top five most unreliable foreign lines of gas boilers.
Malfunctions can be of various kinds, from problems with water heating or ignition, to failure of the make-up tap, circulation pump, plastic elements and even the heat exchanger in the first 3-4 years of operation (more details in the faults section below).
Moreover, even identical models of the same year of manufacture can either work without problems for 10 years or constantly break down in a neighboring house or apartment. There are many factors here: the not entirely successful transfer of production of some models to China (although most are still actually produced in Italy), and the poor quality of the plastic, and the demands on maintenance, cleaning, and the quality of the coolant.
It is especially worth noting the vulnerability of automation to unstable voltage in the domestic power grid. Failure of the control board as a result of a power surge is one of the most common problems. Therefore, we always recommend connecting any gas boiler with complex automation through a voltage stabilizer.
Otherwise, there are quite a few cases of problem-free operation for 5 and 10 years; the installation of boilers is not complicated, but thanks to modern technologies it is effective. But is it worth the risk and buying models, the number of service calls for which was a surprise to us today, when for almost the same amount there are well-known Baxi or slightly more expensive Lamborghinis, not to mention Japanese or German manufacturers.
It is enough to analyze discussions on forums, find out information in any of the service centers, view queries in search engines, or study the most common problems we have identified towards the end of the article.
Kinds
There are different designs of Ferroli double-circuit boilers, differing in certain characteristics.
By installation type:
- Wall mounted . They are installed either on strong (load-bearing) walls or on a special support system - a ramp.
- Floor-standing. They are installed directly on the floor (or on a stand), so they can have more weight and power.
By heat transfer method:
- Convection . The coolant is heated in the usual way, in the flame of a burner.
- Condensation . Preheating of the OM is used using heat obtained by condensation of water vapor from the exhaust smoke. This allows you to reduce the intensity of the main heating and significantly save fuel.
By type of combustion chamber:
- Open or atmospheric . The air is taken from the room, and the smoke is removed using natural draft.
- Closed (turbocharged) . Air is taken from outside and supplied to the combustion chamber using a special fan. The smoke is removed in the same way, which ensures a stable operating mode independent of external factors.
The choice of the most successful configuration is determined by the needs of the user and operating conditions.
NOTE!
The use of condensing boilers in most regions of Russia is impractical, since the full functionality of the unit can only be achieved if the difference between external and internal temperatures is no more than 20°. This must be kept in mind when purchasing an expensive and useless unit under existing conditions.
Ferroli
Ferroli gas boilers are purchased for public buildings and homes. The Ferroli Domicompact C24m model is one of the smallest in size (400*700*330 mm). It is equipped with a copper heat exchanger coated with aluminum and a stainless steel burner.
Italian boilers Ferroli
Italian Ferroli boilers are extremely safe to use, as they have various control systems:
- For example, a system that monitors blocking and, if something happens, turns on the pump every 24 hours of inactivity.
- Anti-freeze function. For the purpose of temperature control of water. The system starts working when the temperature drops to six degrees and stops working as soon as the temperature reaches sixteen plus degrees.
- Built-in self-diagnosis system.
SeriesCharacteristics
| FERROLI DIVA | The Ferroli boiler has a high efficiency of 93.1%, compact dimensions, light weight, elegant design and ease of wall mounting. The unit is equipped with a primary heat exchanger made of copper, which is coated with an aluminum anti-corrosion solution (increases service life!). The boiler's secondary heat exchanger, made of stainless steel, ensures rapid heating of the hot water supply. The combustion chamber is made of steel coated with anti-rust aluminum, separated inside by environmental material. Burners of the FERROLI DIVA series operate quietly and are made of stainless steel. The models are equipped with a security system and electric ignition without a pilot, and an atmospheric (open) combustion chamber. The circulation pump has three speeds. |
| FERROLI Domina FN | The series is represented by the models Domina F 13 N, Domina, F 16 NDomina, F 18 NDomina, F 24 N, Domina F 32 N (the number in the name means the heating power). Recommended heating area from 130 to 320 m². This is a wall-mounted gas boiler with an efficiency factor of 93%. It runs on natural gas, has an open stainless steel burner and an electronic ignition system. The combustion chamber of the FERROLI Domina FN series is sealed, has forced draft and microprocessor control. The electronic board, which is built into the design, can withstand electrical fluctuations of ±30%. The Ferroli boiler kit includes a circulation pump with three speeds, a condensate collector, an expansion tank, a three-way valve and a hydraulic group. The company is responsible for the safety and reliability of units in this series. |
Ferroli Domina FN boiler control panel
You can also pay attention to German, Japanese, Korean, Czech, Russian and Ukrainian gas boilers.
Series and models
Ferroli double-circuit boilers are represented by the following series:
- Divabel. Turbocharged boilers with a capacity of 10, 13, 16, 18, 20 and 24 kW. Produced at the company's own enterprises in the Republic of Belarus.
- Fortuna. Atmospheric and turbocharged models with power from 10 to 40 kW. Produced for use in Russia at Chinese production facilities.
- Divaproject. Manufactured in Italy, the series consists of a single turbocharged model producing 24 kW.
- Divatech D. Series produced in Italy. Consists of three models with a power of 24, 32 and 37 kW. There are atmospheric or turbocharged burner options.
- Bluehelix Tech RRT. Condensing boilers with a capacity of 24, 30 and 34 kW.
- Domiproject D. Boilers with an open or closed combustion chamber. Two models with a power of 24 and 32 kW.
- Diva F. Turbocharged boilers equipped with a separate heat exchanger. Power is 11, 13, 16, 20, 24, 28, 32 and 37 kW.
All of the listed series of double-circuit boilers are wall-mounted. Of the floor-standing units, only boilers of the Pegasus DK 130 series, with a power of 30, 40 and 45 kW, are dual-circuit models.
Which boiler model is ultimately better to choose?
If you have opted for Ferroli boilers, the best in terms of price-quality ratio is the floor-mounted atmospheric Pegasus D, there are not many service requests for it, in most cases the boiler has trouble-free service for 5, 7 and 10 years, and analogues from other manufacturers for its the price is not that much. If the budget is not limited, the best choice is the condensing BLUEHELIX K with a built-in boiler.
Budget wall-mounted models such as Fortuna, Domiproject, etc., despite their high technical characteristics, we do not recommend taking them due to their enormous problems with almost all modules.
How to calculate the required boiler power Individual calculation, formula and correction factors
Specifications
Let's consider the technical parameters of Ferroli double-circuit boilers:
| Parameter | Meaning |
| Boiler type | Gas heating |
| Functions | Heating and hot water preparation |
| Installation type | Wall-mounted or floor-mounted |
| Fuel type | Natural or liquefied gas |
| Heat exchanger type | Separate or combined (bithermic) |
| Combustion chamber type | Atmospheric or closed |
| Power range | 10-45 kW |
| Life time | Warranty - 2 years, operation - about 10 years |
| Power supply | 220 V 50 Hz |
Floor-standing Ferroli boilers for gas and liquid fuel with forced-air burner
In this category, Ferroli today produces five lines; there are several more discontinued (their technical characteristics are worse than those of the new ones). The units differ in design: the burner unit is located outside and is inserted into a hole specially provided in the door. The performance and technical characteristics of the boiler largely depend on the parameters of the burner, since it is responsible for the complete combustion of the fuel.
ATLAS (“Atlas”) is a cast-iron floor-standing boiler with a cast-iron sectional heat exchanger. It has a three-pass firebox structure: a labyrinth is arranged inside the firebox in such a way that the heated air, before exiting into the chimney, passes through this labyrinth and gives off the maximum amount of heat. This heat is then transferred to the coolant. These models have an analog control panel on which data is set using switches.
ATLAS D boilers have a different power range, a cylindrical firebox with a three-pass chimney duct, other powers, slightly lower efficiency. The control system is digital, the panel is LCD, you can connect a remote control, room and external thermostats, based on the readings of which the automation will regulate the power of the equipment. You can connect an external boiler to heat water (indirect heating) or use the ATLAS DK 100_130 model with a built-in 100 or 130 liter stainless steel tank.
Atlas floor-standing boilers with forced-air burners. Can work with gaseous or liquid fuels
High-power floor-standing cast iron boilers GN2 N and GN4 N also work with forced-air burners using liquid or gaseous fuel (natural or liquefied gas).
The body of the GN2 N units is assembled from several sections, which are connected using special steel pins and bushings. The housing is insulated on top, and a metal casing, painted using powder technology, is installed on top of the insulation. The boiler firebox is reversible, the geometry of the heat exchanger with a large number of fins guarantees high efficiency - above 90%. The updated control panel is located under a hinged lid.
Control panel for floor-standing boilers GN2 N and GN4 N
There is an on/off button, an adjustment thermostat, a thermohydrometer, and a restart thermostat. There is also space for installing an electronic adjustment and control unit.
Powerful boilers for heating private houses, offices, etc.
GN4 N have high power (220-650 kW). This line has a three-pass firebox with cooling. The boiler can operate in a normal or low-temperature circuit; it is possible to install external electronic control and cascade connection.
Today, the Ferroli concern also produces solid fuel and condensing boilers. Moreover, all solid fuel models can be converted into full-fledged pellet boilers by installing a burner, hopper and auger.
Device
Ferroli double-circuit boilers are designed based on the most efficient designs used in the global heating industry. The main elements are the gas burner, which is located in close proximity to the heat exchanger.
The hot coolant passes into the secondary heat exchanger, where it transfers some heat to prepare hot water.
IMPORTANT!
In models with a bithermal heat exchanger, both processes occur simultaneously.
At the exit from the secondary heat exchanger, the heating agent enters a three-way valve, where the hot and colder return flows are mixed in the required proportion to obtain the desired temperature, after which the liquid is sent to the heating circuit.
All processes are controlled by an electronic control board equipped with an extensive network of sensors.
They form the core of the self-diagnosis system, which constantly monitors the condition of the boiler components.
Lamborghini
The Lamborghini company produces single-circuit and double-circuit boilers with a closed and atmospheric (open) combustion chamber.
You can learn more about Lamborghini gas boilers in this article
Lamborghini boilers are compact in size and are adapted to low gas pressure. It is possible to connect a remote control and a programmable thermostat.
Gas boiler Lamborghini Taura
SeriesCharacteristics
| Lamborghini Taura | The dimensions of this series of boilers are reduced by an average of 18%, equipped with a safety valve, a recirculation function and a thermohydrometer. Small copper heat exchanger. Open burner made of stainless steel and with smooth power modulation. Electronic ignition system. The heating circuit tank is expanded by 8 liters (24 kW models) and 10 liters (32 kW models). Frost protection function. Can operate at low system temperatures. Efficiency - 93%. |
| Lamborghini Ninfa | The dimensions of the Lamborghini wall-mounted boiler of this series are 13% smaller than traditional boilers of this class. The units have a powerful hot water circuit heat exchanger, as well as a fast hot water production mode and a post-circulation function. Bright display that shows errors and blockages. If desired, you can connect a solar heating system. Small copper heat exchanger. The heating circuit tank is expanded by 8 liters (24 kW models) and 10 liters (32 kW models). Frost protection function. Open burner made of stainless steel and with smooth power modulation. Electronic ignition system. Can operate at low system temperatures. Efficiency - 93%. |
Connection and setup instructions
Connection and configuration of Ferroli double-circuit boilers must be carried out by specialists from service organizations with appropriate training.
All communications are connected:
- Heating circuit forward and return pipelines.
- Water make-up pipeline.
- Gas pipeline.
- Power supply.
After connecting the communications and checking the tightness of the connections, the boiler parameters are adjusted to the existing operating conditions.
The limits of gas pressure, water pressure, temperature in the heating circuit and DHW are determined. These settings are needed to obtain maximum gas savings .
All other adjustments are made by the user in a routine manner and only concern changing the room temperature or switching the boiler to summer/winter mode.
It is strongly not recommended to independently adjust the boiler parameters in order to avoid losing the warranty agreement and causing the unit to fail..
Download instructions
Download instructions for Ferroli double-circuit gas boilers.
Ariston
Italian wall-mounted gas boilers Ariston provide comfort and coziness in the room, save energy and at the same time work with maximum efficiency.
Ariston boilers have a number of advantages:
- The units have a built-in “Automatic” function, which allows you to measure the air temperature outside the window and adjust the operation of the boiler with maximum efficiency.
- A stable supply of hot water is ensured by the “Comfort Plus” mode, thanks to which you can use water at the desired temperature within a few seconds.
- It has a function that allows you to analyze combustion products (“Chimney Sweep”).
- The “Purge” function allows you to remove air bubbles from the heating circuit.
- If desired, you can purchase temperature sensors without wires.
Automation for gas boilers: what it includes.
These Gas boilers from Italy are easy to install and easy to operate.
Connecting a single-circuit gas boiler Ariston
Ariston boilers have the following features:
- increased gap (150 mm) between the wall and fittings;
- access to electrical connections from outside the structure;
- protection against freezing of the hot water supply circuit, heating circuit, protection against scale formation is installed;
- drain valve in the heating circuit.
SeriesCharacteristics
| Ariston Clas Evo System FF | These are Italian wall-mounted gas heating boilers, represented by the names Clas Evo System 28 FF and Clas Evo System 32 FF. Equipped with a stainless steel burner, which has a protection function against periodic switching on. Recommended heating area 280 and 305 m². Has a copper heat exchanger and protective coating. The efficiency of the models is 94%. Combustion products are removed forcibly through an individual smoke removal system. They can operate at low temperatures down to -52°C, have automatic diagnostics and the ability to control the solar collector. Boilers of this series are reliability, quality and affordable price. |
| Ariston Genus Evo FF | This is an Italian double-circuit wall-mounted gas boiler. The design of the Ariston Genus Evo FF series involves a closed combustion chamber. The power of the models is determined by a stainless steel burner and is 24, 28 and 32.5 kW. The recommended heating area is 240, 280 and 325 m². Average efficiency 92%. The combustion chamber of the boiler is closed. Heating circuit pressure from 1 to 3 bar. Voltage 230 V. 35-82°C is the operating temperature of the heating circuit, and 36-60°C is the temperature of the hot water supply. The kit includes a pump with automatic speed control (two modes), an eight-liter tank, two mechanical cleaning filters (in the hot water supply circuit and the heating circuit). It is characterized as compact, fully adapted to Russian conditions, with silent working activity. |
| Ariston Alteas X | The Ariston double-circuit gas boiler (Italy) of this series is represented by the names Alteas X 24 FF NG, Alteas X 30 FF NG, Alteas X 35 FF NG. The power of the models is 24, 28 and 32.5, respectively. Heating area 240, 280 and 325 m². The efficiency is 93%. Chimney diameter 60/100 mm. The volume of the expansion tank is 8 liters. It runs on natural gas, has a closed combustion chamber, and is wall mounted. Separate heat exchanger made of copper. Heating circuit pressure in the range of 0.6-3 bar. Voltage 230 V. The unit can switch to operating on liquefied gas. Control can be carried out via a Wi-Fi module built into the system. |
Control panel of the gas boiler Ariston Alteas X
Basic faults and main error codes
All malfunctions of Ferroli double-circuit boilers are immediately detected by the self-diagnosis system and displayed on the display as an error code.
The most common ones are:
| Code | Decoding |
| A01 | No flame (ignition attempt failed) |
| A02 | False presence of flame (voltage at the ionization electrode when the burner is off) |
| A03 | Boiler overheating |
| A06 | No flame after ignition cycle |
| A08 | Coolant temperature sensor malfunction |
| A09 | Gas valve malfunction |
| F04 | Smoke thermostat overheating |
| F05 | Smoke removal system failure or fan shutdown |
| F08 | Primary heat exchanger overheating |
| F10 | Break or short circuit of the exhaust temperature sensor |
| F11 | Break or short circuit of the DHW temperature sensor |
| F14 | Malfunction of sensor No. 2 direct line of the heating circuit |
| F34 | The supply voltage has dropped below 180 V |
| F37 | Pressure drop in the heating circuit |
| F40 | Excessive pressure in the heating circuit |
| F47 | Open or short circuit coolant pressure switch |
| F50 | Problems with the control board |
Rating of TOP 7 wall-mounted Italian double-circuit boilers
Let's look at the most popular and sought-after models of Italian wall-mounted double-circuit boilers:
Baxi
An Italian company that has been producing gas boilers for about 50 years. The range of wall-mounted boilers is very wide and varied; there are convection and condensation models of varying degrees of power .
The company pursues a policy of producing simple, economical, but high-quality boilers with full functionality.
Modern developments and technologies make it possible to create high-quality and reliable units that are in high demand.
Model lines:
- MAIN.
- NUVOLA.
- ECO.
- LUNA.
Users note the attractive appearance, reliability and stable operation of Baxi boilers.
Ariston
The Ariston brand belongs to the Indesit Company, founded (under a different name) in the 30s of the 20th century.
Today the company occupies a high position among competitors, supplying high-tech and reliable equipment to the world market, including wall-mounted double-circuit gas boilers.
Series:
- Egis.
- Clas
- Genus.
All models are high-tech examples of wall-mounted boilers, equipped with a wide range of functions. Some can be programmed for a week, controlled either from an external panel or from a remote control.
Immergas
The company dates the beginning of its activities to 1964. The energetic and active development of production has yielded results.
Today, several series of wall-mounted double-circuit boilers are offered to buyers.:
- Star.
- Mythos.
- Mini.
- Major.
- Avo/Zeus.
The boilers use a bithermic heat exchanger, which allows obtaining a larger volume of hot water than a conventional separate plate type.
There are models with atmospheric and turbocharged burners, of different capacities, equipped with additional functionality.
Tiberis
The company is a newcomer among the old-timers in the heating industry. However, this does not prevent it from actively developing and producing popular and competitive gas boilers.
Boiler series:
- Tiberis Mini.
- Tiberis Cube.
Relatively inexpensive, but very high quality and reliable wall-mounted boilers. Advanced methods and technologies were used in production, which made it possible to eliminate some weak points in the design and obtain impressive results.
Ferroli
A company that began its path to success in 1958 as a modest workshop. Today it is a world-famous company that produces a wide range of wall-mounted gas boilers.
Series offered:
- DIVATECH.
- BLUEHELIX.
- FORTUNA.
- DIVAPROJECT.
- DIVABEL.
The boilers are designed for operation in difficult conditions, on hard water, with interruptions in power supply and gas supply. They are able to provide the house with heat and hot water and maintain stable operating conditions .
Users note the ease of control and aesthetic appearance.
Fondital
The company was founded in Italy in 1970.
Gas boilers of the following series are produced:
- MINORCA.
- ANTEA.
- FORMENTERA.
- ITACA.
- VICTORIA COMPACT.
Models have great capabilities. There are different types of heat exchangers - both the usual separate version and the more modern bithermal (combined) one.
Italtherm
Purely Italian heating equipment manufactured in Pontenture. The City Class series contains 6 models with a power of 20-28 kW, optimal for a private home with an area of up to 280 m2 .
They are distinguished by a successful combination of quality and cost, and have a lot of functionality.
Price range
Prices for wall-mounted double-circuit boilers from Ferroli are in the range of 27-57 thousand rubles. for conventional models, and 40-80 thousand rubles for condensation structures. Floor-standing double-circuit boilers are much more expensive - 130-190 thousand rubles. depending on power and other specific features.
Industrial models can cost up to 5 million rubles, but, strictly speaking, they cannot be classified as dual-circuit models, since they can only work in conjunction with an external indirect heating boiler.
It is recommended to find out prices and the amount of additional costs in advance, since the cost of equipment largely depends on the region, distance from densely populated areas and other features of the area.
Prices: summary comparison table
| Brand | Model | Type | Number of circuits | power, kWt | Cost, rub | Our rating (0-5 points) |
| BAXI | ECO4S 24 F | wall | 2 | 24 | 35 000 | 4,8 |
| LUNA 3 Comfort 1.240 i | wall | 1 | 24 | 42 000 | 4,8 | |
| SLIM 1.230 iN | floor | 1 | 22,1 | 56 000 | 4,9 | |
| Ferroli | Fortuna Pro F24 | wall | 2 | 24 | 28 000 | 4,5 |
| Pegasus D 23 | floor | 1 | 23 | 65 000 | 4,6 | |
| Ariston | CARES X 24 FF NG | wall | 2 | 25,8 | 32 500 | 4,8 |
| Lamborghini | FL D 24F | wall | 2 | 25,8 | 37 200 | 4,8 |
| Immergas | Eolo Star 24 3 | wall | 2 | 23,8 | 35 000 | 4,6 |
| Fondital | Victoria Compact CTFS 24 AF | wall | 2 | 23,7 | 42 000 | 4 |
| Sime | BRAVA ONE 25 BF | wall | 2 | 23,7 | 35 000 | 4,7 |
| RX 19 CE IONO | floor | 1 | 22 | 54 000 | 4,3 |
