Overview of single-circuit and double-circuit gas boilers Volcano

Advantages of double-circuit boilers over single-circuit boilers

At the choice of users, the manufacturer offers single-circuit and double-circuit models. By purchasing a unit with two circuits, you will be provided not only with heating, but also with hot water. This option is very convenient, because.you do not have to separately buy and install a boiler.

Double-circuit boilers have a number of advantages:

• firstly, you will save space, since two functions will be combined in one device;
• secondly, fuel consumption will be much lower;
• thirdly, the performance of the boiler is much higher than that of water heaters.

Two completely independent circuits will optimally heat both pipes and water for plumbing. They can operate in different modes, and the temperature for them is set separately.

Automation floor gas boilers Volcano is made in accordance with high European standards. Thanks to this element, any emergency situations will be prevented.

In the event of any malfunctions, the built-in safety module immediately shuts off the gas, which will avoid an explosion or fire in the room. A large number of fuses that provide protection to the main computer from sudden voltage drops.

Owner's review gas boiler Volcano

How to prevent wind blowing?

When designing the location of the device, it is necessary to take into account such nuances as wind blowing - whether it happens from the side of the house of interest, and if so, how strong. The chimney diagram must be correct, if it does not correspond to the project, it is necessary to make changes to the device. The pipe that discharges gases should be insulated. It should rise half a meter above the roof ridge. The diameter is selected according to the power of the equipment. To avoid blowing, you need a lot of traction, for this:

• Clean the chimney from soot and soot.
• Increase the air flow to the maximum. The opening through which the air enters should be located near the floor and as close as possible to the machine.

The principle of operation of gas boilers

All existing models can be divided into two main groups:

Convection boilers have a simpler design and low cost. You can find these models everywhere. Heating of the coolant occurs solely due to the effect of an open flame of the burner. In this case, most of the thermal energy is transferred to the heat exchanger, but some (sometimes quite significant) part of it is lost along with the discharged products of gas combustion. The main drawback is that the latent energy of water vapor, which is part of the removed smoke, is not used.

Convection boiler Gaz 6000 W

The advantages of such models include a fairly simple design, the possibility of diverting combustion products due to natural draft (if there are chimneys that meet the requirements).

The second group is convection gas boilers. Their peculiarity lies in the following - convection equipment cannot use the energy of water vapor removed with smoke. It is this drawback that the condensing circuit of a gas boiler allows to eliminate.

Gas boiler Bosch Gaz 3000 W ZW 24-2KE

The essence of the operation of such devices is that combustion products that have a sufficiently high temperature pass through a special heat exchanger, into which water enters from the return of the heating system. Provided that the temperature of such a coolant is below the dew point for water (about 40 degrees), steam begins to condense on the outer walls of the heat exchanger. In this case, a sufficiently large amount of thermal energy (condensation energy) is released, which provides preheating of the coolant.

But there are some negative points that characterize the condensation technique:

To operate in condensing mode, it is necessary to provide a return temperature of no more than 30-35 degrees. Therefore, such units are mainly used for low-temperature (not more than 50 degrees) heating systems. Also, boilers of this type can be used in systems with high heat transfer, for example, in systems with a warm water floor. Boilers in which a condensing heat exchanger is used to provide hot water have proven themselves quite well.

Maintenance and adjustment of the optimal operating mode of the boiler can only be performed by a competent specialist. In the regions, there are not too many craftsmen who can understand condensing boilers. Therefore, maintenance of the device can be quite expensive.

In addition, the very cost of equipment of this class is high, it will not be possible to attribute such equipment to the budget option even with a strong desire.

But is it really worth giving up the opportunity to save more than 30% of the energy carrier because of such shortcomings. It is this savings and the short payback period of condensing boilers that make their purchase expedient from an economic point of view.

Boilers with open and closed combustion chamber

Such boilers differ significantly in their technical capabilities, while the conditions for their use also differ.

Atmospheric boilers are equipped with an open combustion chamber. The air necessary for gas combustion enters the chamber directly from the room. Therefore, when choosing such boilers, it is necessary to strictly control compliance with the regulatory requirements for air exchange in the room.An effective ventilation system must operate in the room, in addition, the removal of combustion products in the natural draft mode is possible only with the installation of high chimneys (smoke removal above the level of the roof of the building).

Wall-mounted gas boiler Logamax U054-24K atmospheric double-circuit

The advantages of such boilers include a fairly reasonable cost, simplicity of design. But it should be borne in mind that the efficiency of such units is most often not too high (compared to more advanced models).

The turbocharged wall-mounted double-circuit boiler is equipped with a closed-type combustion chamber. Such units are connected mainly to coaxial chimneys, which provide not only the removal of combustion products, but also the supply of fresh air to the combustion chamber from the street. To do this, a low-power electric fan is built into the design of the boiler.

Gas boiler FERROLI DOMIproject F24 wall-mounted double-circuit turbocharged

The main advantage of a turbocharged boiler is increased productivity, while the efficiency of the device reaches 90-95%. This makes it possible to reduce fuel consumption. But it is worth considering that the cost of such boilers is quite high.

Advantages

The brand positions its heating equipment as optimal according to the "price-quality" formula. Boilers "Navien" can be used for heating a private house, apartment, industrial premises. Their advantages:

• Resistant to voltage drops. Its jumps often lead to equipment failure. The Koreans provided reliable protection - they installed a Switched-Mode Power Supply control chip - it expands the voltage range to 165-300 V.
• Resistant to reduced gas pressure.Many modifications refuse to work because of this, but not Navien - they continue to work at the lowest values.
• Nice, ergonomic design.
• Any Navien boiler is double-circuit. So, in addition to heating, its owner receives an addition in the form of hot water supply.
• A wide range of capacities is offered - you can choose an option for any room.
• Equipment owners can always get professional help at the service center. Contact details can be found in the attached documentation.

Popular manufacturers

The most famous companies producing wall-mounted single-circuit gas appliances with a closed-type combustion chamber are domestic Siberia and Neva and a number of European concerns, such as Vaillant, Lemax, Protherm and Viessmann.

Among the models, Vaillant Turbo Tec Plus VU 122 modifications 3-5 are very popular. The device is able to provide efficient space heating up to 120 sq. m. Power adjustment is carried out using a modulating burner. Due to the presence of a stabilizer, the boiler can function even in the event of a decrease in gas pressure in the network, and there is no loss of performance. The disadvantages of the model include the high cost of the device, which is quite understandable for its high quality and long service life.

Baxi boilers are also in high demand. Among them, the most popular is the Fourtech version 1.24 F. The device is equipped with a modulating burner that allows you to change the heating power, and a copper heat exchanger, thanks to which water is heated almost instantly. The boiler efficiency is 93%. The weak point of the model is the gas valve, which sometimes breaks down and needs to be replaced.

The Korean Navien device is also quite popular in the domestic market for heating equipment. The boilers are perfectly adapted to Russian fuel and gas communication networks. Models of this brand are optimal in terms of price-quality ratio and, despite the low cost, are capable of developing power up to 13 kW. The disadvantages of the series are a weak thermostat and automation failures.

Which gas boiler Weller to buy?

In practice, boilers of the hinged type receive more sales. Floor structures of a Chinese manufacturer are not so in demand. This is true among those who want to organize autonomous heating at home.

Why are Weller gas boilers popular? There are several reasons for this:

1. Often they buy a model with two circuits Mars 26, which is designed to heat housing up to 240 m². The equipment is distinguished by the presence of a modulating burner, which is responsible for the most productive work at any power. It should be noted the closed furnace and the condensing module, which additionally collects heat from the exhaust gases. The gas supply is automatic, manual pressure regulation in the system is not required. Gas boiler Weller Mars 26 is connected to a vertical chimney. Air intake and removal of combustion products is forced by means of a coaxial chimney.

Wall-mounted gas boiler Weller Mars 26

The Mars 32 model is no less popular. The performance of this boiler is higher due to the assembly with components of European brands Wilo, SWEP, FUGAS and others. The boiler is also installed on the wall, has two circuits, elementary control, as well as a self-diagnosis system.The equipment is equipped with a multi-level security system that controls the functionality of the entire structure. In the event of any failures, the system signals and turns off. The display notifies of an error using a special code. There is a separate heat exchanger.

Reviews indicate that during the operation of the equipment a minor drawback may be identified: the control unit may not work correctly due to power surges. Safety is ensured by installing an uninterruptible power supply.

Product Overview of Leading Brands

This review should begin with gas boilers, which took first place in the popularity rating not only among our compatriots, but also among European consumers. These are the products of such German giants as Vaillant Group and Wolf.

Boiler equipment from Vaillant Group

Vaillant Group is a recognized leader in the production of heating gas boilers. In the domestic market, Vaillant Group is represented by almost all possible modifications of heating equipment:

1. Line of wall-mounted boilers. atmo TEC series with open fuel chamber, turbo TEC series with closed combustion chamber.
2. Line of floor boilers. The iro VIT series is equipped with an electronic security and self-diagnosis system, the avto VIT series are fully automated devices.

Single-circuit boiler units are indicated by the letter index VU. A feature of these heating devices is the equipment of almost all models with circulation pumps.

Double-circuit heating installations are designated by the letter index VUW.In addition, boilers of this brand are produced both in standard (PRO) and modernized (PLUS) versions. The nominal power of Vaillant boilers varies depending on the model from 12 to 36 kW.

Heating equipment from Wolf

The company's products have repeatedly been awarded certificates confirming their environmental friendliness and safety. In the domestic market, brand heating boilers are represented by:

1. Line of floor heating units. The FNG series can run on both natural gas and liquefied gas, the CHK series features an exclusive design.
2. Line of wall-mounted boilers. CGG series - double-circuit boilers, can be both with open and closed fuel chamber, CGU series - single-circuit boilers with simple control.
3. Condensing boilers of the MGK range.

Boilers for individual heating from Viessmann

The model range of Viessmann concern heating devices is represented by the Vitopend line, which includes floor and wall-mounted devices, with a closed and open fuel chamber. The performance of the units varies depending on the model and can be:

• for wall-mounted boilers from 10.5 to 31 kW;
• for floor installations up to 140 kW.

Heating equipment from Buderus

The products of this German manufacturer became famous among our compatriots for their compactness and design features.

The line of wall-mounted devices is represented by a series of double-circuit boilers Logamax and condensing equipment Logamax plus. The range of underfloor heating boilers includes the Logano series, which is a hit in the first half of this year.

Protherm's products

Gas boilers of this manufacturer are widely represented in Russia and occupy a strong position in the markets of Eastern Europe. The most popular models include:

• a line of wall-mounted double-circuit heating units of the Pantera series, which is perfect for heating and hot water supply of small private houses, summer cottages and individual apartments;
• a series of Cheetah, characterized by an ideal ratio of price and quality;
• modification Lynx - these are wall-mounted devices for individual heating;
• Leopard boiler models adapted for operation in gas pipelines with low pressure indicators;
• a line of floor-standing boilers Bear, which are characterized by unpretentiousness, high performance and ease of operation.

Boiler equipment "Baxi"

An overview of the heating devices of the Italian company Baxi can be started with a line of wall-mounted appliances:

• the MAIN FOUR series, represented by two double-circuit models with a power of 24 kW with an open and closed combustion chamber;
• the Fourtech line includes 6 models, including 4 single-circuit and only two double-circuit models with different versions of the combustion chamber, power from 14 to 24 kW;
• Ecofour modification differs from Fourtech only in components, the number of models, design and power are identical;
• the Luna 3 Comfort series of boilers has 6 models, including an equal number of single- and double-circuit boilers with different types of combustion chamber, power from 24 to 31 kW;
• the model range of the Luna 3 Comfort Air series is represented by two turbocharged boilers with a capacity of 24 - 31 kW;
• the Luna 3 Avant series differs from previous models in the presence of an additional condensing heat exchanger, the power of the devices is 24 - 31 kW;
• SLIM is a line of floor-standing single-circuit boilers with an open combustion chamber, represented by 11 models with a capacity from 15 to 116 kW.

TOP-5 double-circuit gas boilers

Double-circuit boilers among users are considered the most preferred option.

This is true, although for families with a large need for hot water, it is better to use single-circuit models with an external drive. Double-circuit units are convenient for small families or for use in public buildings. Popular Models:

Vaillant turboTEC pro VUW 242/5-3 24 kW

German boiler from one of the most reliable manufacturers. It has a power of 24 kW, which allows heating rooms up to 240 sq.m. with simultaneous hot water supply.

Unit parameters:

• installation type - wall-mounted;
• power consumption - 220 V 50 Hz;
• type of heat exchanger - separate (primary copper and stainless secondary);
• Efficiency - 91%;
• gas consumption - 2.8 m3/hour;
• dimensions - 440x800x338 mm;
• weight - 40 kg.

Advantages:

• fully provides housing with heat and hot water;
• reliable stable operation;
• developed network of service centers.

Flaws:

• needs to stabilize the power supply;
• high price for boilers and spare parts.

Vaillant units are considered the most stable and reliable in operation. This is confirmed by ordinary users and service specialists.

Buderus Logamax U072-12K 12 kW

Gas boiler made in Germany. Refers to the elite samples of European heat engineering. The power is 12 kW, allowing you to heat 120 sq.m.

Characteristics:

• installation type - wall-mounted;
• power consumption - 220 V 50 Hz;
• Efficiency - 92%;
• type of heat exchanger - separate (primary copper, secondary stainless);
• gas consumption - 2.1 m3/hour;
• dimensions - 400x700x299 mm;
• weight - 29 kg.

Advantages:

• stable and reliable operation;
• no noise;
• Ease of controls.

Flaws:

• high price;
• the need to use a power stabilizer and a water filter.

If, during installation and first start-up, filtering units and a stabilizer are not immediately installed, you can quickly disable the unit and incur unnecessary costs for repair and restoration of the boiler.

Bosch Gaz 6000 W WBN 6000- 12 C 12 kW

Gas double-circuit convection boiler with electronic control. Designed for rooms up to 120 sq.m., since it power is 12 kW.

Characteristics:

• installation type - wall-mounted;
• power consumption - 220 V 50 Hz;
• Efficiency - 93.2%;
• type of heat exchanger - separate (primary copper, secondary stainless);
• gas consumption - 2.1 m3/hour;
• dimensions - 400x700x299 mm;
• weight - 28 kg.

Advantages:

• reliability, stability of work;
• no noise;
• low gas consumption.

Flaws:

• the high cost of spare parts and repairs;
• demands on the quality of water and electricity.

Bosch products are known all over the world and need no introduction. The quality and reliability of heat engineering are considered reference and serve as an example for other manufacturers.

BAXI LUNA-3 240 Fi 25 kW

Italian double-circuit convection boiler. With a power of 25 kW, it can heat an area up to 250 sq.m.

Options:

• installation type - wall-mounted;
• power consumption - 220 V 50 Hz;
• Efficiency - 92.9%;
• type of heat exchanger - separate (copper-stainless steel);
• gas consumption - 2.84 m3/hour;
• dimensions - 450x763x345 mm;
• weight - 38 kg.

Advantages:

• reliability;
• high performance;
• high-quality components and parts of the unit.

Flaws:

• high cost;
• the dimensions of the boiler are too large for a wall model.

Italian boilers are famous for their quality and reliability. However, to work in Russian conditions, it is necessary to use additional equipment - a stabilizer and filter units.

Navien DELUXE 16K 16 kW

Korean boiler, characterized by relatively low cost and high quality. With a power of 16 kW, it is able to heat 160 sq.m. area.

Boiler characteristics:

• installation type - wall-mounted;
• power consumption - 220 V 50 Hz;
• Efficiency - 91.2%;
• type of heat exchanger - separate (both units are made of stainless steel);
• gas consumption - 1.72 m3/hour;
• dimensions - 440x695x265 mm;
• weight - 28 kg.

Advantages:

• reliability, high build quality;
• relatively low price;
• adapted to Russian conditions.

Flaws:

• high noise level (relative);
• some parts are made of unreliable plastic.

South Korean boilers are classified as a budget segment of heat engineering. However, their quality is not inferior to European counterparts, and the price is much lower.

Typical malfunctions

A common cause of malfunctions of gas boilers is clogging of heat exchangers with scale.

Despite the high reliability inherent in all Vaillant brand products, there are several drawbacks. More often than other users note:

• Plate heat exchangers quickly become clogged with scale, and therefore it is necessary to install special filters that soften the water.
• Increased noise level during the operation of the built-in fan.
• Water ingress into the pump, which is caused by insufficient reliability of its seals.
• unstable operation of electronics caused by voltage fluctuations in a centralized power grid. These shortcomings are eliminated by installing a voltage stabilizer.

Properly performed installation work will allow you to avoid trouble during operation.

After installing and connecting the boiler to existing communications, the following work must be performed:

• check the correct installation of the check valve in the heating system;
• remove air from the heating system;
• before the first start-up of the boiler, carefully check all the settings of the heating circuit;
• carry out a test run, during which to check the functioning of all systems in heating and water heating modes;
• check the operation of all automation, control and protection systems.

It is better to entrust the carrying out of the listed works to a qualified specialist who has access to the performance of such work.

troubleshooting

In the event of a boiler malfunction, the system displays relevant information on the display screen.

All Vaillant boilers are equipped with a built-in fault testing system. When an error occurs, the system displays the corresponding information on the display screen. Errors that block the operation of the boiler may occur due to unstable power supply or broken contacts in the wire connections from the sensors to the electronic module. Such problems can be corrected by checking the signal lines for:

• wire breaks or oxidation of lamellas and contact groups;
• shorting the wires to the case or to each other;
• wire insulation damage;
• loose contact in the connectors.

Having eliminated the identified malfunctions and provided a stabilized power supply, you can reset the error by pressing the Reset button.

The best hinged convection type boilers

This type of heating equipment can be called the most common. Not surprisingly, almost all buyers prefer these models. They combine ease of use, compact size, good performance and low price compared to condensing units.

1

Buderus Logamax UO72-12K

Convection boiler for double-circuit heating systems

Characteristics:

• Price - 32 445 rubles
• Customer rating - 4.8
• Max. power - 12 kW
• Efficiency - 92%
• Fuel consumption - 2.1 cubic meters. m/h

The model has a modern design, so it is often placed inside residential premises. Device with closed combustion chamber and built-in circulation pump.

The indisputable advantage of the model is high efficiency and a built-in expansion tank of 8 liters. The maximum temperature of the coolant reaches 82%, which is higher than most convection units. Frost protection, on indication and forced shutdown in case of overheating are provided.

Maximum heated area - 120 m2

Advantages:

• good performance;
• copper primary heat exchanger;
• capacious expansion tank;
• circulation pump;
• Possibility to connect external control.

Flaws:

• there is no safety valve;
• no built-in temperature controller.

2

Bosch Gas 6000W

High-quality double-circuit boiler of a well-known German manufacturer

Characteristics:

• Price - 32 450 rubles
• Customer rating - 4.7
• Max. power - 20 kW
• Efficiency - 92%
• Fuel consumption - 2.1 cubic meters. m/h

Characterized by high efficiency. Suitable for heating apartments and houses up to 200 sq. m.

The model is equipped with a closed combustion chamber. Can operate on both natural and liquefied fuels.The unit has a built-in expansion tank of 8 liters, which significantly increases the productivity of hot water.

The maximum temperature in the water supply circuit is 60 degrees

Advantages:

• compactness;
• modulating burner;
• built-in manometer, thermometer;
• work timer.

Flaws:

• high fuel consumption;
• inconvenient management;
• noise when using hot water.

3

BAXI ECO-4s 24F

High quality model from the Italian brand

Characteristics:

• Price - 31,570 rubles
• Customer rating - 4.6
• Max. power - 24 kW
• Efficiency - 92.3%
• Fuel consumption - 2.7 cubic meters. m/h

The double-circuit boiler, with a wall-mounted type of installation, has a stylish modern design.

Despite the convection principle of operation, it is characterized by a record efficiency indicator. The advantage of this heater is electronic control. The design includes an expansion tank with a volume of 6 liters.

BAXI ECO-4s 24F uses 2 types of heat exchanger - steel and copper

Advantages:

• low noise level;
• work from natural and liquefied gas in cylinders;
• built-in water filter;
• ease of operation;
• combined heat exchanger.

Flaws:

high fuel consumption.

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Pros and cons

The advantages of floor boilers include:

• no restrictions on the power of the unit;
• strength, reliability of all components and parts;
• ease of installation;
• stability of work, the ability to maintain a given mode regardless of external conditions;
• lack of unnecessary additions;
• powerful models can be connected in a cascade of up to 4 units, forming high-performance thermal units.

The disadvantages of floor structures are:

• large weight, size;
• the need for a separate room;
• for atmospheric models, connection to a common house chimney is required

IMPORTANT!
In addition to a separate room, for floor-standing boilers, it is necessary to provide the possibility of connecting to a vertical chimney or leading a horizontal pipe through the wall.

Types of boiler ignition methods and which method is the most optimal?

There are three ignition options:

• electronic. The burner is ignited at the touch of a button using a special unit. This option is present on all models of volatile boilers;
• piezoelectric. The principle of operation of such a system is similar to all piezo devices - for a spark to appear, you need to press on a special crystal. Used on non-volatile boilers. Many users find this type of ignition inconvenient;
• manual. The flame is ignited with an ordinary lit match (torch). For ignition, it is necessary to have some supply of such elongated wooden sticks.

Most users unanimously prefer the electronic type of ignition, but it is not possible on non-volatile units. You have to get used to using a piezoelectric element or setting fire to the burner with a burning torch.

Burner type and outlet system

Another important item from the list of parameters is the definition of the device of the gas exhaust system. It must be understood that the correctness of the choice of the gas boiler device will be checked by the supervisory authorities that issue a permit for its operation.

1. An open burner uses oxygen directly from the room, so it requires an efficient supply ventilation system to operate. The gases must be removed by natural draft. In their reviews, people write that at least 4 meters of chimney is required.In an apartment building, this is an almost impossible task.
2. Gas boilers with a closed burner work a little differently. The air in them is forcibly pumped, which means that a huge chimney is no longer needed, the combustion products are removed by a fan through a coaxial pipe.

When choosing a gas boiler, be sure to pay attention to these parameters. They are important for obtaining permission to use

Conclusions and useful video on the topic

This video will help you understand the features of various types of gas boilers:

The video material is intended to deepen knowledge on the topic and help you make the right choice:

When making a choice between a double-circuit boiler and its single-circuit counterpart, you should not ask yourself which is better. Since all of the above equipment is modern, productive and durable, but, as mentioned above, is designed to solve different problems.

Therefore, it is so important to take into account personal needs and living conditions so that the equipment does not disappoint you.

And how many circuits does your gas boiler have? Share your impressions of using your heating equipment - tell us whether the selected boiler satisfies all your needs or for some reason you consider your choice to be wrong? Add a photo of your gas boiler, indicate its pros and cons found during operation.