Gas boiler - 100 photos of general selection principles for a heating system

Which gas boiler is better to buy?

The power of heating equipment is the first thing you need to determine before purchasing. It is calculated using the heating area taking into account the climate zone. At first, with a standard ceiling height of up to 3 m, you can get by with simple calculations: multiply the housing area by the coefficient for your region, and divide the total by 10. As a result, you will get the approximate boiler power in kW.

Power factors for different regions of Russia:

1. southern region 0.7-0.9

2. middle band 1-1.2

3. moderately cold climate 1.2-1.5

4. northern region 1.5-2

According to calculations, for a house with an area of 100 square meters in the middle zone, a boiler of 10-12 kW will be required. When purchasing a dual-circuit unit, the total power will increase by 20%.

Not only the organization of space, but also the safety of using gas equipment depends on the method of installing the boiler. Wall mounting will save space, but the compactness of the model will entail a number of technical limitations. The burner, exchanger, pump and control electronics will be too close to each other, which will create an intense temperature regime for their operation and complicate maintenance.

Compact wall-mounted models have power limitations - they are more suitable for an apartment than for a private house. Floor-standing boilers, as a rule, are installed in separate rooms, so their overall dimensions, as well as thermal power, are not limited by anything other than common sense.

The types of gas burners do not depend on the type of boiler chosen, but determine the principle of its operation and performance:

Atmospheric burners are inexpensive and almost silent. But they burn out the air in the room and have low efficiency.
Supercharged ones are equipped with an air supercharger supplied from outside. Boilers with such burners are efficient and do not require installation in a separate room.
Modulating burners with adjustable power can be equipped with a second heating stage or electronic heat transfer control. Their efficiency and cost-effectiveness increases simultaneously with the price of the boiler.

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Determining the thermal power of the boiler

Surely you know the popular methods for calculating the thermal performance of equipment - by area or volume of heated premises. Allegedly, for a dwelling of 100 square meters a 10 kW boiler is taken, for a country house of 200 square meters. m – unit 20 kW.

It is better not to use these approximate methods, since specific conditions are not taken into account - the climate in the area of residence, the degree of thermal insulation of the building, and so on. We suggest using more accurate calculation methods:

According to the specific heat load per square square of living space, taking into account the location of the room and the number of window openings.
The same goes for the volume of premises.
Full calculation using the SNiP formula, taking into account the thickness and thermal insulation of external building structures.

An example of calculating heat loss by area, taking into account the location of rooms and the number of window openings

Comment. All 3 methods are described in detail in a separate guide to calculating the heat load for heating a residential building.

Knowing the heat consumption for heating the cottage, we select a gas boiler based on power as follows:

if you plan to use the unit only for heating, multiply the resulting figure by a safety factor of 1.2;
the power of a 2-circuit heat generator providing 2 water draw-off points is best selected with a margin of 1.3-1.5;
To work with an indirect heating boiler with a volume of 200-300 liters, you will need a gas single-circuit boiler with one and a half capacity reserve (multiply by a factor of 1.5).

Let's give an example. For heating a private home with an area of 100 square meters. m is calculated to require 9 kW of energy. The minimum power of a gas heater excluding DHW will be 9 x 1.2 = 10.8 kW, a double-circuit boiler - 9 x 1.3 = 11.7 kW. If you need to heat the storage tank, the unit’s performance increases to 9 x 1.5 = 13.5 kW. Next, we select the nearest higher-power model from the line of heaters - 12 and 15 kW, respectively.

The best wall-mounted gas boilers

This section presents single-circuit room heating systems placed on the wall. They are compact and easy to maintain, although they have some limitations in functionality.

Viessmann Vitopend 100-W A1HB003

4.9

★★★★★

editorial assessment

89%

buyers recommend this product

The A1HB line includes three boilers with a capacity of 24, 30 and 34 kW. This is enough to heat a home with an area of up to 250 m2. All cases are equally compact: 725x400x340 mm - such units have a place in any room.

Viessmann boilers are assembled on a single modular platform, which simplifies their installation and maintenance. In addition, there is no need to leave additional space near the body, so any Vitopend can be combined with kitchen furniture if there is a free corner for it.

Advantages:

Low gas consumption - no more than 3.5 m3/h in the older model;
The valve body is equipped with quick-release connectors;
Automatic power adjustment depending on the outside temperature;
Efficiency up to 93%;
New coaxial chimney system with frost protection;
Intelligent control with self-diagnosis function;
Possibility of switching to liquefied gas.

Flaws:

There is no remote control panel.

Viessmann provides the opportunity to choose a boiler for an apartment of any size. The appearance and dimensions for the entire line are absolutely the same - the models differ only in performance and, accordingly, gas consumption.

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Baxi Eco Four 1.24 F

4.8

★★★★★

editorial assessment

88%

buyers recommend this product

See review▶

Despite the prestige of the brand, the Eco Four model is relatively inexpensive. The boiler has a flat body measuring 730x400x299 mm, which allows it to be hung flush with kitchen cabinets. When used in northern latitudes, such a unit can heat an apartment up to 150 m².

Fourth generation boilers were developed taking into account our operating conditions. That is why the presented model operates even when the inlet gas pressure is reduced to 5 mBar. In addition, it has two separate thermostats: for heating radiators and for the “warm floor” system.

Advantages:

Built-in water flow meter;
Pump with air vent and post-circulation mode;
It is possible to connect to solar collectors;
Dual-mode thermal control;
Pressure switch for protection against low coolant pressure;
You can connect a remote thermostat and remote control.

Flaws:

Low-informative built-in display.

As for Baxi, Eco Four's price is very attractive. In addition, this is an excellent solution for placement in a small kitchen or studio apartment.

Vaillant AtmoTEC Plus VU 240/5-5

4.7

★★★★★

editorial assessment

87%

buyers recommend this product

This boiler has all possible means of protection: gas control, pressure switch with safety valve, pump air vent. Here, overheating of the medium and combustion chamber, freezing of liquid in the system and in the chimney are completely excluded. The built-in auto-diagnostics helps monitor the correct operation of all systems.

AtmoTEC is adapted for operation in Russia: it takes into account the low quality of main gas and can operate on LNG. The programmer control is fully automated, and the panel itself is covered with a neat decorative cover.

Advantages:

Volumetric expansion tank 10 l;
Low gas consumption – 2.8 m³/h (or 1.9 m³/h when connected to a cylinder);
Almost eternal chrome-nickel burner;
Possibility of combination with other heaters;
The minimum side clearance during installation is 1 cm.

Flaws:

Classic (atmospheric) chimney.

The boiler dimensions of 800x440x338 mm and a maximum power of 36 kW are more suitable for a private home than for a city apartment. Although in a spacious kitchen there will be no problems with its placement.

TOP 5 energy-independent gas boilers

Non-volatile boilers are a good choice for working in remote villages or regions with overloaded and dilapidated electrical networks. They continue to work in the event of a sudden power outage and do not require high costs for repairs or replacement of failed components. Let's look at the most popular models:

Lemax Patriot-12.5 12.5 kW

Single-circuit parapet gas boiler. Equipped with openings in the housing that allow heated air to escape outside.

This makes the boiler itself similar to a convector, heating the room without the need to install radiators . The boiler power is 12.5 kW, which is suitable for rooms of 125 sq. m.

Its parameters:

installation type - floor;
energy consumption - independent;
Efficiency - 87%;
gas consumption - 0.75 m3/hour;
dimensions - 595x740x360 mm;
weight - 50 kg.

Advantages:

simplicity of design, reliability;
low fuel consumption;
easy controls;
low price.

Flaws:

there is no complete information about the condition of the unit components. There is only a pressure gauge. indicating gas pressure;
it is necessary to install a traditional type chimney.

Domestic boilers are optimal for Russian climatic and technological conditions. They are unpretentious and reliable, do not require expensive repairs or maintenance.

Lemax Leader-25 25 kW

Convection gas boiler with a capacity of 25 kW . Designed for use in rooms up to 250 sq.m. The unit is single-circuit, with a cast iron heat exchanger and mechanical control.

Its parameters:

installation type - floor;
energy consumption - independent;
Efficiency - 90%;
gas consumption - 1.5 m3/hour;
dimensions - 515x856x515 mm;
weight - 115 kg.

Advantages:

strength, reliability of design;
stability, smooth operation;
Italian components.

Flaws:

large weight and size;
Some users find the ignition procedure unnecessarily complicated.

Boilers with a cast iron heat exchanger are characterized by smooth operation and the absence of sudden temperature changes.

Lemax Leader-35 35 kW

Another domestic boiler designed for large rooms . With a power of 35 kW, it is capable of heating an area of up to 350 sq.m., which is suitable for a large house or public space.

Boiler parameters:

installation type - floor;
energy consumption - independent;
Efficiency - 90%;
gas consumption - 4 m3/hour;
dimensions - 600x856x520 mm;
weight - 140 kg.

Advantages:

high power, ability to heat a large room;
stable and efficient work;
double-circuit boiler provides heat and hot water at the same time.

Flaws:

large size and weight, requiring a separate room;
gas consumption is quite high.

High-power boilers are often used to heat several apartments or houses. This reduces the financial burden on homeowners, since fuel payments are shared equally by everyone.

MORA-TOP SA 20 G 15 kW

Gas convection boiler manufactured by Czech engineers. The power of the unit is 15 kW, suitable for work in a house with an area of up to 150 sq.m.

Main settings:

installation type - floor;
energy consumption - independent;
Efficiency - 92%;
gas consumption - 1.6 m3/hour;
dimensions - 365x845x525 mm;
weight - 99 kg.

Advantages:

independence from electricity supply;
stability of work;
The power is suitable for most medium-sized private houses.

Flaws:

an atmospheric burner requires a normal chimney and does not allow drafts in the room;
relatively high price.

Compared to their Russian counterparts, European boilers are noticeably more expensive. Users note excessive costs, as well as interruptions in the supply of spare parts.

Siberia 11 11.6 kW

Domestic single-circuit gas boiler. Suitable for small rooms up to 125 sq.m. This is due to the boiler power of 11.6 kW.

Specifications:

installation type - floor;
energy consumption - independent;
Efficiency - 90%;
gas consumption - 1.18 m3/hour;
dimensions - 280x850x560 mm;
weight - 52 kg.

Advantages:

stable work;
unpretentious, economical boiler. Fuel consumption is noticeably lower than that of analogues from other manufacturers;
ease of management and maintenance;
relatively low price.

Flaws:

the declared indicators cannot always be achieved, the boiler power is sometimes not enough;
Difficult and inconvenient ignition.

Non-volatile boilers are optimal in Russian conditions. In cold weather it is too dangerous to remain without heating, so the independence of boilers is highly valued by users.

The best floor units

Let's consider single-circuit units of large and medium dimensions that have no restrictions on functionality. They are installed on the floor and most often require a separate room for installation.

Bosch GAZ 2500 F

4.9

★★★★★

editorial assessment

89%

buyers recommend this product

See review▶

This is the first floor-standing gas boiler developed by Russian engineers at Bosch - specifically for use by our compatriots. The unit is capable of operating at unstable network voltage and low gas pressure. At the stands, the GAZ 2500 proved that it can operate without serious breakdowns for 20 years. Partly thanks to the heat exchanger made of 3 mm thick steel.

The series includes 4 models with power from 22 to 42 kW. But despite the domestic assembly, they cannot be called cheap. But these boilers can be connected to an external indirect heating boiler (optional). And the capabilities of the built-in automation explain the rather high cost.

Advantages:

Large capacity heat exchanger;
Flexible power change within 60-100%;
Fully automated control;
Preset modes that do not require configuration;
Availability of remote control;
Temperature change according to schedule;
Possibility to reconfigure the boiler to use bottled gas.

Flaws:

High price.

Bosch GAZ really has no problems adapting to our operating conditions. All critical elements are made specifically for Russia and have a good margin of safety and reliability.

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Protherm Bear 40 KLOM

4.8

★★★★★

editorial assessment

88%

buyers recommend this product

A reliable and efficient boiler with a cast iron heat exchanger is an excellent solution for a private home, without restrictions on the size of the boiler room. The thermal power of this model is 35 kW with a maximum gas flow of 4.1 m3/h. A cast iron heat exchanger is installed inside - almost eternal with proper operation.

All electronic components are imported, protection and control automation are already included in the kit. Operation data is displayed on an LCD display, on which you can monitor both the temperature of the medium and the pressure in the system.

Advantages:

Heat exchanger service life is 25 years;
Full set of automation included;
Ease of maintenance;
Possibility of connection to LNG cylinders;
Relatively small dimensions.

Flaws:

Thin metal of the outer lining of the case (does not affect the quality of work).

If aesthetics and appearance are not a priority for you, “Bear” is ideal. The reliability of the boiler is excellent, the equipment is the same as that of top models, and the price is the most affordable among imported analogues.

Calculation of gas consumption for heating a house

Now let’s calculate whether it is profitable to install gas heating in a private house. To do this, let’s calculate how many liters are spent on heating.

To calculate the gas consumed, it is necessary to multiply the amount of kW needed to heat the house by one tenth of the volume of gas. Then you will be able to find out how many cubic meters of gas are consumed in one hour.

For example, we have a house with an area of 250 square meters. Then a 25 kW boiler is needed to heat the house. Then:

25 kV * 0.1 m3 = 2.5 m3/h.

This means that the following is consumed per day:

2.5 m3/h * 24 h = 60 m3

For a month (we take 30 days):

60 m3 * 30 d = 1800 m3

They calculate a year like this: choose three cold months and add three more months to them, during which the boiler will work at half power. For convenience, take 100 days in the first and 100 days in the second case. Then for a year it turns out:

(60 m3 * 100 d) + (30 m3 * 100 d) = 9000 m3

For houses with a smaller area, this figure is, of course, less. Moreover, what comes out mathematically does not always correspond to practice. Usually the real figure is less than the stated one.

When calculating, only heating is taken into account.

Simple manipulations will help reduce the amount of heat loss and gas consumption:

It is necessary to pay attention to the thermal insulation of the house. This also applies to the roof.
Replace, if necessary, the windows with plastic ones and replace the doors.
Install a heat accumulator, heating radiators, that is, equipment that allows you to use heat economically.
Insulate the floors.

The best inexpensive boilers

Low price does not always mean low quality. If the manufacturer saves on minor parts that do not affect the operation of the boiler, such a purchase will be justified.

Lemax Premium-30

4.9

★★★★★

editorial assessment

89%

buyers recommend this product

See review▶

A 30 kW unit is suitable for budget-conscious homeowners for heating an area of no more than 250 m2. The range of functions here is minimal, but all the necessary security features are there. The manufacturer abandoned complex electronic components, so the boiler is completely energy-independent - just connect it to the gas supply, and everything will work.

The floor model itself is well made, the heat exchanger inside is made of steel. And with an efficiency of 90%, Lemax consumes a minimal amount of blue fuel - no more than 1.75 m3/h.

Advantages:

Good build quality;
Gas control;
There is protection against overheating;
Very economical;
Heating of the coolant up to +90 °C.

Flaws:

Manual control.

To maintain the required temperature in a system connected to Lemax, constant monitoring will be required. Otherwise, there will be no problems with it, and a non-volatile boiler will save a lot of money.

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Mora-Top Meteor Plus PK18ST

4.8

★★★★★

editorial assessment

88%

buyers recommend this product

See review▶

The Czech company Mora is known for its high-quality gas stoves. But the heating boilers of this brand are no worse. Here, for example, is a wall-mounted single-circuit Meteor Plus with a thermal power of up to 19 kW, a built-in expander and a circulation pump. It works flawlessly, consumes no more than 2.16 m3/h of gas, has the entire minimum set of protective functions and at the same time costs much less than branded analogues.

Advantages:

Burner with automatic modulation;
Low fuel consumption;
Possibility of external control;
Quiet operation;
There is protection against overheating and freezing;
Calmly tolerates changes in gas pressure.

Flaws:

Not the highest efficiency (90%).

To install Mora, you will need a little more space than compact Italian or German models, and this boiler is inferior to them in design. But Meteor is worth its cost and is extremely easy to maintain.

Which model should you prefer?

To ensure the most efficient operation of a gas boiler, when choosing an installation it is worth considering:

Estimated power. It is indicated in the technical data sheet for the product. The higher this indicator, the higher the performance of the device. The optimal option is determined on the basis that 1 kW of unit power is enough to heat 10 square meters. m. For double-circuit units, this figure is increased by another 30-40%.

Floor-standing condensing gas boiler
Combustion chamber type. When choosing a device with an open chamber, you can use a regular chimney to remove combustion products. For heating installations with closed chambers, it is necessary to provide for the installation of turbine chimneys, in which the movement of combustion products is carried out under air pressure created by a fan.
Automated control system. By creating and maintaining an optimal ratio of the components of the combustible mixture in the combustion chamber, it will ensure highly productive combustion of gas.
Installation dimensions and control ergonomics. The ability to set the desired parameters to create the most comfortable conditions.
Compliance with safety standards. Preference should be given to products from leading manufacturers that produce certified products.

Floor standing gas boiler

When deciding which gas boiler to install in a private home, you should be guided by what problem you want to solve with its help. If there is a need only for heating the coolant, it is not at all necessary to overpay by purchasing a double-circuit unit. It is better to prefer a single-circuit floor-standing boiler, which, thanks to its high technical performance, will provide maximum heat with minimal energy consumption.

The best double-circuit gas boilers

Double-circuit boilers simultaneously heat water for both the heating system and DHW. In this section we will look at the best units without a built-in boiler.

Haier Aquila

4.9

★★★★★

editorial assessment

89%

buyers recommend this product

The series of wall-mounted double-circuits includes 4 models of boilers with a capacity of 14, 18, 24 and 28 kW. In central Russia this is enough to heat an area of 100-200 square meters. The burner and heat exchanger here are made of stainless steel and are not afraid of corrosion. The secondary circuit tube is copper so that the running water has time to heat up.

The control in all Haier models is electronic: there is an LCD display on the body, which simplifies communication with the boiler automation. It is possible to connect a remote room regulator - with it the unit will be able to automatically adjust the burner power to maintain the set temperature. The manufacturer did not forget about the full range of protections: against overheating, freezing, extinguished flames, and reverse draft.

Advantages:

Small dimensions 750x403x320 mm;
Daily and weekly operating mode programmer;
Work using an external temperature sensor;
Possibility of switching to liquefied gas;
Built-in pump with electronic control and dry start protection;
The room sensor is already included;
Heating of the coolant up to +90 °C.

Flaws:

Non-Russian menu.

A well-made and attractive-looking boiler will fit perfectly into a city apartment. It will not only make you warm, but will also solve the problem of hot water.

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Baxi LUNA-3 Comfort 310 Fi

4.8

★★★★★

editorial assessment

88%

buyers recommend this product

See review▶

The main highlight of this model is the removable control panel, made in a separate housing. You can leave it on the boiler, or secure it in any convenient place. The socket has one more secret - a built-in temperature sensor. Thanks to it, the boiler can automatically adjust the burner power within the range of 10-31 kW, focusing on the specified parameters. You can also adjust the water temperature in the second circuit - from 35 to 65 degrees.

Advantages:

Convenient control from a remote panel;
Quick heating of the heating system (relevant for northern regions);
Automatic restart in case of network outages;
The built-in pump pumps coolant up to the 3rd floor;
A good efficiency indicator is 93%.

Flaws:

There is no circulation of hot water in the second circuit.

Baxi LUNA-3 is premium in everything: from the appearance of the boiler to its equipment and level of safety.

The best models with a built-in boiler

In fact, these boilers are a 2-in-1 system. The circuit with the expansion tank works to heat the room, and the storage boiler stores hot water for household needs. All this is placed in one housing, which is why such boilers turn out to be quite large.

Baxi Slim 2.300 i

4.9

★★★★★

editorial assessment

89%

buyers recommend this product

A powerful floor-standing boiler, stuffed with automatic equipment responsible for energy efficiency and safety of gas equipment. The 30 liter boiler heats up quickly and maintains the temperature for a long time, saving fuel. There are also two pumps in the housing: one for the heating system, the second for hot water.

The total thermal power of Baxi Slim is 30 kW. Depending on the characteristics of the connected system, it can heat the coolant to +30..+45 or +85 degrees (for heated floors, the temperature is maintained at the lower limit).

Advantages:

Cast iron heat exchanger in the heating circuit;
Freeze protection for pipes and media;
Possibility of connecting room and weather automation;
Presence of safety valves on both branches;
Flame control;
Operation when fuel pressure drops to 5 mbar.

Flaws:

High price.

Baxi Slim is a fully automated mini-boiler room and boiler room for a country house. However, to take advantage of all its capabilities, you will have to separately purchase and connect the necessary sensors.

Beretta Boiler 28 BSI

4.8

★★★★★

editorial assessment

88%

buyers recommend this product

It’s generally difficult to imagine a wall-mounted model with a storage tank, but this unit is just such a 2-in-1 boiler. In addition to a closed chamber with access to a coaxial chimney, a 60-liter storage boiler also fits inside the Beretta body, which quickly heats the second circuit of the heat exchanger.

28 BSI is equipped with weather-dependent automatic control, its own circulation pump, and a 10-liter expansion tank. In a heating system it can maintain temperatures in the range of +40..+80 °C, in DHW up to +63 degrees.

Advantages:

Excellent build quality;
The closed chamber does not burn oxygen;
Intelligent control;
Availability of preset operating modes;
Possibility of connecting to LNG;
A complete set of protection, including for work in northern latitudes.

Flaws:

Rare, scarce product.

Even those who do not understand the operation of boiler equipment will be able to operate the Beretta Boiler. All pre-installed programs are already here, and the owners will not have to interfere with the settings.

The best double-circuit wall models

A double-circuit gas boiler is an indispensable device for those who need hot water in addition to heating.

Stay up to date! These models are quite compact in size. There is no need to buy additional equipment for heating water.

The power of the devices is much higher than single-circuit ones . They are easy to install - all necessary wall mountings are included.

Double-circuit gas boilers can be used in the summer without heating, using a heat exchanger to produce hot water.

Rating of the TOP 5 best models of mounted models in terms of price, reliability and quality.

Lemax PRIME-V32 32 kW dual-circuit

A budget model that has received many positive reviews from customers due to its high quality and low cost.

Quite a powerful unit that allows you to heat rooms in an apartment or private house.

The boiler can be controlled autonomously via a smartphone, which is very convenient.

It is equipped with an anti-freeze system, electronic ignition, and a durable copper heat exchanger.

Specifications:

thermal power - 11-32 kW;
heat exchanger material - copper;
control - electronic;
combustion chamber - closed;
dimensions - 430x770x340 mm;
weight - 32 kg.

Advantages

stylish design;
easy installation;
low cost;
reliable protection;
high-quality components included in the set;
good power.

Flaws

small expansion tank;
connecting hose is too short;
not always high-quality assembly.

Bosch Gaz 6000 W WBN 6000-24 C 24 kW dual circuit

The best model in terms of price and quality ratio, occupies a leading position in sales.

The boiler is a convection type and has good power.

It has many useful additional functions, such as protection against freezing, overheating, auto-diagnosis, auto-ignition.

The warranty period has been increased compared to analogues - it is 2 years. A special feature of the model is its high hot water performance.

Specifications:

thermal power - 7.2-24 kW;
heat exchanger material - copper;
control - electronic;
combustion chamber - closed;
dimensions - 400x700x299 mm;
weight - 32 kg.

Advantages

does not make noise during operation;
efficiency;
a large number of settings;
laconic exterior;
heats water quickly;
low price;
convenient control;
reliable brand.

Flaws

high cost of spare parts;
with sudden temperature changes, condensation accumulates in the tubes;
Self-installation voids the warranty;
small hot water outlet.

Navien DELUXE COAXIAL 24K 24 kW dual circuit

Convection gas boiler with excellent heat and hot water performance.

The stylish, discreet design of the unit allows it to be installed anywhere.

Compactness and ease of installation complete the good impression. This model will last about 10 years.

There is also a 2 year manufacturer's warranty. Therefore, in case of any malfunctions, the device can be replaced without any problems.

Specifications:

thermal power - 9-24 kW;
heat exchanger material - stainless steel;
control - electronic;
combustion chamber - closed;
dimensions - 440x695x265 mm;
weight - 28 kg.

Advantages

good value for money;
remote control panel;
Beautiful design;
inexpensive maintenance;
quiet in operation;
works normally at low gas pressure;
Automatic shutdown in case of any emergency.

Flaws

cannot be installed in heating systems filled with antifreeze;
expensive repairs for any breakdowns;
inconvenient control panel.

MORA-TOP Meteor Plus PK24KT 23 kW dual circuit

A distinctive feature of this model is its economical gas consumption.

The device has clear controls, all information is displayed on the electronic display.

Ideally copes with the function of supplying hot water and completely replaces heating devices.

The optimal replacement for a boiler - it does not consume as much electricity, and also heats fairly large rooms.

Specifications:

thermal power - 8.9-23 kW;
heat exchanger material - copper;
control - electronic;
combustion chamber - closed;
dimensions - 400x750x380 mm;
weight - 33.5 kg.

Advantages

consumes gas economically;
convenient control;
availability of autodiagnostics;
high performance;
can work in energy saving mode;
easy to set up.

Flaws

high price;
not always high-quality assembly;
expensive spare parts.

Kentatsu Nobby Smart 24–2CSF 23.8 kW dual circuit

A quiet boiler that fully copes with its responsibilities.

A modern model with a laconic design and intuitive controls.

Excellent ratio of price and quality functionality.

The device can also be controlled remotely from a smartphone, which is very convenient for constantly busy people.

Specifications:

thermal power - 9.4-23.8 kW;
heat exchanger material - copper;
control - electronic;
combustion chamber - closed;
dimensions - 403x733x329 mm;
weight - 35 kg.

Advantages

does not make noise during operation;
uninterruptedly provides heat and hot water;
low price;
high build quality;
comfortable control.

Flaws

not very clear instructions - not enough information;
heavy in weight;
complex installation process.

The best condensing gas boilers

These boilers are considered the most economical because they can use the energy of not only gas combustion, but also condensing steam. As a result, their efficiency is almost close to the coveted 100%.

Vaillant ecoTEC plus VUW

4.9

★★★★★

editorial assessment

89%

buyers recommend this product

See review▶

Stuffed with intelligent electronics and eBus switching, the unit works not only for efficient heating, but also for preparing hot water, that is, it also belongs to double-circuit units. The capacitor system is more environmentally friendly compared to the traditional one, and also provides a very high efficiency of 98%.

The combustion chamber is equipped with a modulating burner with wide power adjustment capabilities (from 28 to 100 percent). With such efficiency and equipment, the dimensions of the boiler are quite acceptable: 720x440x372 mm. The ecoTEC line itself consists of three models with a maximum power of 24, 30 and 34 kW.

Advantages:

Digital control and diagnostic system;
The most informative panel;
Possibility of control from a mobile phone and connection to a “smart home”;
The burner can receive air both from the room and from the street;
Short-term increase in power for quick water heating;
Removal of condensate outside.

Flaws:

Difficult to repair;
High price.

ecoTEC Plus boilers still scare off many due to their high cost. But there is minimal hassle with them, and the fuel savings will pay off the investment over time.

Viessmann Vitodens 100-W

4.8

★★★★★

editorial assessment

88%

buyers recommend this product

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An expensive boiler, capable of operating at a power of 4.7-35 kW, saves not only blue fuel, but also electricity - due to the adjustable operation of the fan. This model also has other highlights. We are talking about a cylindrical MatriX burner, consisting of many micro-nozzles, which practically does not allow heat loss. A ring heat exchanger made of stainless steel works no less efficiently.

Advantages:

Compact housing 400x400x350 mm;
Two ways to prepare hot water;
Maximum efficiency and energy efficiency;
High efficiency (98%);
Intelligent automation;
Remote control – from a touch panel or smartphone;
Possibility of working on LNG and biogas;
Easy access for repairs and maintenance.

Flaws:

Price.

If your home is equipped with a smart home system, the equally smart Viessmann Vitodens will be the best solution for creating a heating and hot water system.

Combustion chambers of units

They come in open and closed types. The key difference is that in open-type installations, the oxygen necessary to maintain combustion comes directly from the room in which the unit is installed. The process of combustion and heating with the removal of combustion products occurs under the influence of draft in the chimney.

Attention! When choosing a gas boiler with an open combustion chamber, during installation you should ensure conditions for natural ventilation. It is better to allocate a separate room for this – a boiler room.

Compliance with this condition will ensure a continuous supply of air in sufficient volume. Otherwise, this may cause carbon monoxide poisoning in the household.

Gas boiler design

If the gas boiler is equipped with a closed combustion chamber, then in this case it will be connected to the chimney by a structure of two pipes. The inner pipe is designed to remove combustion products, and the outer pipe is designed to supply fresh air into the chamber. This design cannot work due to draft in the chimney and therefore requires the presence of a fan.

Installations with closed combustion chambers have higher efficiency, which is achieved due to more efficient fuel combustion. The temperature of the gases exhausted to the outside decreases, and the air is additionally heated by the heat released from the combustion products.

Scheme: boiler with a closed chamber

How to choose a gas boiler

The best manufacturers of gas boilers - which company to choose

The installation of an effective heating system begins with the purchase of a boiler. But first you need to choose it correctly, and to do this, you need to take into account many nuances. One of them is that it is better to purchase the unit from one of the reputable companies that have positively proven themselves in the market.

Such companies include the following:

Vaillant;
Buderus;
Baxi;
Protherm;
Bosch.

These manufacturers are among the best - they have a wide range of models that are in demand among users.

Top manufacturers of gas boilers for Russia

Italian and German manufacturers have gained the greatest popularity in Russia. These are mainly brands such as Viessmann, Bosch, Vaillant, Buderus. The Italians mainly recommended the companies Baxi, Beretta and Ariston. Among the top European models, Protherm, Slovakia, can also be noted. The good and fairly widespread Korean brand Navien presents a fairly wide range of its products in Russia.

Of the common domestic manufacturers, of course, the company Lemax (AOGV Gazovik), gas boilers ZhMZ (Zhukovsky Machine-Building Plant) type AOGV (Vulcan) and AGKV (Helios). Basically they have fairly simple gas boilers.

Less popular brands include the Taiga gas boiler, country of origin Ukraine, the Korean company Koreastar (Buran boilers), Italian boilers Sime, Thermex (Termex), Lithuanian AOGV Mayak, Slovakian Thermona, Zhytomyr boilers Atem, Polish Thermet (Termet), Rostov RGA 11, Aridea.

Among industrial gas boilers, we can highlight the Khoper 100 model, produced by the domestic Irbis plant.

Among boilers produced in Belarus, one can highlight the company Alfa-Kalor (produced jointly with Italy), among the Chinese – Oasis, and the French – De Dietrich. There are also Turkish manufacturers.

Operating principle and design of gas boilers

A gas boiler is a wall-mounted or floor-mounted unit, predominantly rectangular-parallelepiped in shape, which generates energy when burning fuel and thereby ensures the functioning of heating and hot water supply systems.

In general, the boiler consists of the following elements:

1. Body;

2. Burner;

3. Heat exchanger;

4. Circulation pump;

5. Exhaust for combustion products;

6. Monitoring and control unit.

Depending on the design, the boiler operates in one of several modes - according to a simplified scheme: gas is supplied to the burner, which is turned on by a piezoelectric element or electricity; the fuel ignites and heats the coolant through a heat exchanger; the latter is forced to circulate in the heating system using a pump.

During operation, safety systems play an important role, preventing overheating, freezing, gas leaks, pump blocking and other troubles.

There are individual characteristics in the operation of units. In the option with a 2-circuit model, hot water supply is additionally provided. In the case of an open firebox, combustion products will be removed through the chimney; with a closed chamber, through a coaxial pipe. Condensation models also use steam energy.

Type of operation of heating equipment for a private home

Installation diagram of a solid fuel heating boiler.

Boilers for heating houses differ in the type of their operation. In this case, the design of the boiler (wall-mounted or floor-mounted) does not matter.

Single-circuit models, which are initially intended only to provide heating for a private home, can also be used to heat water for domestic needs (wash dishes, take a shower, etc.), that is, provide your home with hot water supply, but require the addition of additional devices and components , such as pumps and indirect heating boiler. Such a boiler room design requires a separate room due to its dimensions, but it makes it possible to choose the equipment that is suitable for your home.

Double-circuit boilers for home heating are very popular, which are initially intended for both heating and providing hot water supply. A unit is already built into the body of such devices, which provides heating of water for domestic needs, which saves space in the room, but narrows the choice of equipment. For example, the power of the built-in hot water supply unit is designed for 2 simultaneously operating points, and you have more than 2 of them.

In addition, chimney and flueless boilers are available on the market. When any type of fuel (except electricity) is burned, combustion products are released in the form of smoke. These products must be discharged into the chimney. The chimney itself must be separate for the boiler and installed above the roof of the house. Such equipment cannot operate without a chimney.

Chimneyless models are often called turbocharged. Combustion products are removed using a special fan (turbine). A chimney for such models is still necessary, but it is installed differently: not vertically and not higher than the roof of the building, but is discharged horizontally through the wall. A chimney of this type is called coaxial, and its length is 50 cm or more. If a chimney was not provided in your home, then choosing such equipment allows you to save significantly.

Types of gas boilers

With open combustion chamber

Boilers with an open combustion chamber use air that comes directly from the room with the equipment located there to maintain the fire. Discharge is carried out using natural draft through the chimney.

Since a device of this type burns a lot of oxygen, it is installed in a non-residential, specially adapted room with 3 times air exchange.

These devices are absolutely not suitable for apartments in multi-storey buildings, since ventilation wells cannot be used as chimneys.

Advantages:

simplicity of design and, as a result, low cost of repairs;
no noise during operation;
a wide range of;
relatively low cost.

Flaws:

the need for a separate room and chimney;
unsuitable for apartments.

With a closed combustion chamber

For units with a closed firebox, there is no need for a specially equipped room, since their chamber is sealed and does not directly contact the internal air space.

Instead of a classic chimney, a horizontal coaxial chimney is used, which is a pipe in a pipe - one end of this product is attached to the top of the device, the other goes out through the wall to the street. Such a chimney works simply: air is supplied through the external cavity of the two-pipe product, and exhaust gas is removed through the internal hole using an electric fan.

This device can be installed both in apartments and houses, and in any room convenient for use.

Advantages:

no need for a special room;
operational safety;
relatively high environmental friendliness;
easy installation;
ease of use.

Flaws:

dependence on electricity;
high noise level;
High price.

Single-circuit

A single-circuit boiler is a classic heating device with a local purpose: preparing coolant for the heating system.

Its main feature is that the design, among many elements, provides only 2 tubes: one for the entry of cold liquid, the other for the exit of already heated liquid. The composition also includes 1 heat exchanger, which is natural, a burner and a pump that pumps coolant - in the case of natural circulation, the latter may be absent.

When installing DHW, an indirect heating boiler is connected to the CO system - taking into account the possibility of this prospect, manufacturers manufacture boilers compatible with this storage device.

Advantages:

relatively low fuel consumption;
simplicity in design, maintenance and repair;
the possibility of creating domestic hot water using an indirect heating boiler;
acceptable price.

Flaws:

used only for heating;
For a set with a separate boiler, a special room is desirable.

Dual-circuit

Double-circuit units are more complex - one ring is intended for heating, the other for hot water supply. The design can have 2 separate heat exchangers (1 for each system) or 1 joint bithermic one. The latter consists of a metal body, an outer tube for CO and an inner tube for DHW.

In standard mode, the water, heating up, is supplied to the radiators - when you turn on the mixer, for example, a sink, the flow sensor is triggered, as a result of which the circulation pump is turned off, the heating system stops working, and the hot water supply circuit begins to function. After closing the tap, the previous mode resumes.

Advantages:

providing hot water to several systems at once;
small dimensions;
simple installation;
affordable price;
possibility of local heating shutdown for the spring-autumn season;
large selection, including design;
ease of use.

Flaws:

DHW flow diagram;
accumulation of salt deposits in hard water.

What to look for when choosing

It is best to select a device for use at home with a professional who has experience installing these units. When making your own choice, you should pay attention to the following main characteristics.

Location type

If it is possible to allocate a separate area for boiler room equipment, it is best to choose a floor-standing boiler. These devices are affordable and easy to use. Floor-standing boilers are often equipped with reliable cast iron heat exchangers, since weight in this case is not particularly important.

Limited space forces you to purchase wall-mounted boilers. Modern models of such boilers are made in the form of rectangular or square devices with small dimensions.

Parapet boilers, which are also wall-mounted products, are more expensive, but are energy independent and smoke-free, which is important for ensuring a normal microclimate in the house.

Number of circuits

If the device is purchased exclusively for organizing heating in the house or only for hot water supply, it will be enough to purchase a single-circuit model. If you need to combine both functions in one device, it is recommended to use dual-circuit type devices.

Single-circuit devices can be equipped with boilers in which water is heated for hot water supply, but in such a situation the load on the device increases significantly, which leads to rapid wear of the main elements.

Type of heat exchanger

The service life and quality of operation of the heat exchanger depends on the material from which it is made. Cast iron ones are considered the most reliable - they are durable and cope well with temperature loads.

Copper heat exchangers are also highly resistant to high temperatures, and they are also fairly easy to repair if leaks are detected. Steel products last much less than cast iron heat exchangers - they quickly become slagged, as a result of which they must be replaced frequently.

Dual-circuit devices use dual or separate heat exchangers. The best solution would be to choose a device with separate elements, which, due to this, will last much longer.

Cast iron heat exchanger.

Combustion chamber and ignition type

The type of combustion chamber depends on the type of oxygen supply to the apparatus. In open-type chambers, oxygen comes from the room in which the device is located; in closed chambers, an artificial flow of oxygen is organized.

To organize the heating of a city apartment, it is better to purchase boilers with closed turbocharged burners, since such devices are easy to install, equipped with a coaxial flue exhaust and have high efficiency.

Boilers with an open combustion chamber are installed in separate boiler rooms with the obligatory organization of a chimney, which will provide the necessary draft.

To ignite the gas in the burner, piezo or electric ignition is used. If there are frequent problems with the supply of electricity, a system based on piezoelectric elements will be more reliable, and in the absence of such problems, electric ignition is used.

Adjustable

Additional control functions allow you to use fuel more efficiently, increase the efficiency of the boiler and maintain the required level of safety during operation of the device.

Single-stage regulation provides the only option for turning the boiler on and off, and when the device is equipped with a modulator, it becomes possible to smoothly adjust the intensity of gas combustion. Automatic adjustment occurs according to specified parameters and can function without owner control in autonomous mode.

The safety of the boiler is ensured by pressure and combustion sensors, which send a signal to the control panel of the device, resulting in the adjustment of the boiler operation or its complete shutdown in emergency situations.

Power

This characteristic allows you to determine the boiler’s capabilities to ensure sufficient heating of water in the heating network of a house or garage and organize hot water supply. Manufacturers indicate the power in kW in the instructions, and often recommend the size of the area that this device can heat.

In devices manufactured for heating coolant at home, power values can vary from 8 to 40 kW.

How to determine the required power

An exact calculation of the required boiler power for a specific room can only be made by a specialist, but there are approximate consumption standards per square meter of living space.

For areas of central Russia it is 1 kW per 10 m2; for areas with long winters and low temperatures, it is recommended to take 1.5 kW for the same area, and for warm climate zones 0.8 kW is sufficient.

A coefficient of 10-20% should be added to the value obtained by calculation, which will compensate for heat needs during abnormal weather changes in the area.

Gas boiler selection parameters

Power

To calculate power, you can proceed from the rule: 1 kW of thermal energy heats a residential area of up to 10 m2 - more accurate calculations take into account: ceiling height, number of external walls, window sizes, connection with the attic (basement), area of residence, wind rose and others factors.

If the device (single-circuit) is also needed for hot water supply (+ indirect heating boiler), the consumption mode is additionally taken into account, as well as the number of dismountable points and residents - this is approximately + 30%.

Since the equipment will not work for a long time at maximum capacity, another 20% is added to the obtained value. Taking into account all the nuances, it is quite realistic that for a house with an area of 120 m2 you will need a boiler with a capacity of 20 kW.

Design

Based on the design, the devices are:

1. With an open combustion chamber, atmospheric burner, internal air intake, exhaust gas removal through a vertical chimney;

2. With a closed firebox, turbocharged burner, air supply and combustion products exhaust through a coaxial horizontal chimney.

Number of systems served

Based on the number of systems served, the devices are divided into 1- and 2-circuit.

1. With the help of single-circuit heating, you can additionally install an indirect heating boiler and receive hot water immediately after opening the tap.

2. Double-control units are more suitable for apartments - they are compact and easy to install, for example, in the kitchen.

Installation type

Depending on the type of installation, boilers are divided into wall-mounted and floor-mounted.

1. The first ones have low power and a steel heat exchanger; in addition, they are compact and lightweight, so they fit perfectly into apartment kitchens.

2. The latter are more suitable for private houses with a rather large square footage. In such dwellings, as a rule, powerful and heavy units with a cast iron heat exchanger are installed.

Availability of automation

An important role in the operation of the devices is played by automation, which controls the operation of all key components. Temperature sensors are installed on the CO and DHW circuits - with their help, the optimal operating mode is maintained, water and electricity are economically consumed.

Protection system

The protection system is at a high level - it reacts to an electrical outage, if necessary, extinguishes the flame and shuts off the gas supply. In addition, in the event of a breakdown, error information is displayed.

Nuances for choosing a good gas boiler for heating and hot water supply

The first thing you need to pay attention to when choosing a device for heating and hot water is power. It all depends on how much space you need to heat. 250, 300 or 1000 sq. m., etc. When selecting a gas boiler according to its parameters online, in the characteristics section you can find the approximately calculated area of the heated room for any model.

If you need to choose a unit for your dacha, then most likely a low-power device will be sufficient. There are gas boilers for sale with 5, 6, 7, 8, 9, 10 kW. Options with average power 11, 12, 14, 15, 16, 18, 20, 24, 36, 45 kW. And high-power devices 60, 70, 80, 90, 120, 200, 300, 400 kW

There is no point in buying high-power boilers for small rooms. Gas and electricity consumption for such boilers will be higher.

Below we will consider the selection criteria depending on the material, location, etc.

Selection by material and design of heat exchanger

Gas boiler heat exchangers are made of cast iron, steel, copper or aluminum.

Cast iron heat exchangers are highly resistant to corrosion and are less susceptible to various chemicals. Cast iron retains heat longer, therefore its efficiency is higher. However, the cons rather outweigh the pros in the literal sense. It is very heavy and bulky. Devices with a cast iron heat exchanger are manufactured only in a floor-standing version and take up quite a lot of space.

Steel heat exchangers respond better to temperature changes, they are much lighter, but are susceptible to corrosion. Therefore, the service life is 2 or even 3 times less than that of cast iron. You should not buy boilers with steel heat exchangers if the steel thickness is less than 3 mm. Ideally 5 mm.

Copper are perhaps the best heat exchangers in existence. Copper is light, practically does not corrode, has excellent heat dissipation, heats up and cools down quickly, and takes up little space. The downside is of course the price.

There are also aluminum heat exchangers. Aluminum is also not susceptible to corrosion, although it tends to oxidize. Due to the lower price of the material than copper sheets, the thickness of the heat exchanger sheets is greater, and accordingly the service life is longer. At the same time, aluminum also tends to heat up and cool down quickly. Mainly used on condensing boilers.

Heat exchangers can be bithermal, with two channels for a double-circuit gas boiler, or conventional. Double-circuit boilers can also be equipped with two conventional heat exchangers.

Device location

The boiler can be in two versions. Floor or wall mounted. The floor-standing device is usually equipped with a cast iron or steel heat exchanger with a long service life. The wall mounted one takes up much less space and can be installed in a living space, for example, a kitchen. The shape is round or rectangular. Round gas boilers are no different from rectangular ones; it’s a matter of taste and aesthetics. There are mounted models with cascading capabilities.

How many contours to choose

There are two main types. Single-circuit and double-circuit boilers.

Single-circuit devices are designed either to organize only heating in a private house, or only to supply hot water. True, there is also an option with a single-circuit device for heating and hot water supply. To do this, connect an indirect type boiler, into which an outlet is made for supplying hot water from the boiler.

To save fuel, double-circuit boilers also use a boiler. This allows you to heat a large volume of water in advance, rather than using the boiler only in the flow-through version.

There are also three-circuit gas boilers, if it is necessary to allocate another heating circuit, for example to another floor. For example, the Immergas Hercules Condesing 32 ABT 2L model.

Combustion chamber, ignition type, burner device

The combustion chamber is of open and closed type. A boiler with an open combustion chamber takes in air from the room naturally.

Devices with a closed combustion chamber take in oxygen by forced air intake through a coaxial chimney or a specially installed ventilation pipe.

Accordingly, in the first case an atmospheric burner is used, in the second a turbocharged one. It is worth noting that gas boilers with an open combustion chamber are not suitable for everyone. To ensure normal draft in the chimney, its height should be 5 - 6 meters.

Units with an open combustion chamber are mainly installed in the boiler room, because oxygen is being burned. Such boilers are also available in a non-volatile version, which are independent from power outages.

Protection devices, automation

Look for various protection devices. Be sure to choose protection against gas supply interruption, overheating and freezing. Of course, modern, especially foreign models are stuffed with various kinds of protective electronics and there is no doubt about the availability of these systems. But domestic models are closely watched.

It would be good if the boiler is equipped with a repeat self-start function if errors occur (for example, due to a stop or decrease in pressure in the gas line). This will help prevent the heating circuit from freezing if you are away from home for some time.

As for automation, it is better to choose a device with power control with smooth flame modulation. In essence, the height of the flame is adjusted due to the intensity of the gas supply and a certain number of burners is turned on or off. This helps select a power range from 15 to 100%.

Particularly technologically advanced boilers can be controlled remotely and connected to the Smart Home system.

To sum it up, we can say that independently choosing the right device with the required quality is a real task. Currently, in almost any online store you can compare the characteristics of various heating boilers. You can use our recommendations, while others prefer to use the live services of a sales consultant. Below you can watch a useful video on the topic of choosing gas boilers.

Which gas boiler to choose

Domestic gas boilers are most often used in private houses and apartments, although the latter usually have centralized heating - perhaps not the most efficient. Installation also takes place in cottages, dachas, bathhouses and similar facilities.

1. The following type of boiler is suitable for apartments: 2 circuits, closed combustion chamber, coaxial chimney, convection type of heating, electronic control, wall mounting, power ranging from 10 to 30 kW

2. The following type of boiler is suitable for a home: 1 circuit + indirect heating boiler, open firebox, vertical chimney, specially equipped room, condensation heating, electronic control, floor installation, power from 20 to 50 kW.

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Features of gas heating systems

Still, to choose a suitable device, just look at the rating of gas boilers. But what advantages do gas boilers have over other energy sources, and how does this manifest itself in everyday life?

As already mentioned, the heating system can be built on other energy sources. The very essence of the boiler is to heat a certain volume of water and then send it through the pipes. As a result, the liquid will begin to release heat into the building, and the temperature will gradually rise. But we did not mention the “triangle” of choice, which should be applied when considering each type of ASO (autonomous heating system):

Your total budget allocated for the creation of an ASO.
The efficiency and practicality of the device in the use of the resources provided to it, the necessary monthly costs for heating the entire building.
Ergonomics and dimensions of the boiler. The more complex the installation, the more money from the budget will be spent on paying for the services of specialists from the gas company.

In all respects, two varieties are in the lead: gas boiler and electric. Here it is worth understanding that gas boilers are larger and much more dangerous, because in the event of a breakdown, leaks of flammable substances are possible. On the other hand, they are a little more economical and cost less. Even if there is no gas main nearby or your gas has been turned off, you can always use cylinders. And this is much simpler than an autonomous energy source, which is necessary to start electric boilers if your lights are turned off.

That is why in private homes it is better to take the gas variety. But, when choosing a product, terms such as “Single-circuit”, “Double-circuit” will often flash before you. How to understand which gas boiler is better, because even the best gas boilers for a private home, the ratings of which are posted on the seller’s website, may not suit your conditions of use. Let's figure out which gas boiler to choose and when it is better not to use it at all.

You can read about the pros and cons of single-circuit and double-circuit gas boilers at the link.