Top 7 smallest wall-mounted gas boilers

Home » Classification of gas boilers » Top - 7 smallest wall-mounted gas boilers

Most of us live in a small house or apartment. Therefore, when installing a gas heating system, owners want the boiler to take up as little space as possible. Many people place it in small bathrooms or kitchens. This generates interest in small wall-mounted gas boilers that have minimal dimensions. Most of the mounted units have a height of 700 mm, a width of 400 mm and a depth of 250 mm. Let's consider models of gas boilers with the smallest dimensions.

…

1 Ferroli DOMIproject Slim F18
2 Ferroli DOMITECH C24
3 Bosch Gaz 3000 W ZS 28-2KE
4 Teplovest KGO-18-S BUDGET
5 Fondital Antea CTFS 24
6 Ferroli FER EASYtech C 24
7 TERMET MiniMax DYNAMIC 24 kW (turbo)

Ferroli DOMIproject Slim F18

One of the smallest wall-mounted gas boilers is Ferroli DOMIproject Slim F18. Its height is 655 mm, width – 350 mm and depth – 230 mm. Weight is only 27.3 kg.

This double-circuit model with a closed combustion chamber has a power of 18 kW, which is enough to heat an area of up to 150 m². It has a bithermic heat exchanger and is equipped with the “Comfort” function for accelerated preparation of hot water.

The unit is equipped with a digital heating system, a modulating burner that can change power in the range from 6.7 to 18 kW. Thanks to easy access to internal elements, this gas boiler is easier to service.

Main characteristics of Ferroli DOMIproject Slim F18:

…

Efficiency=90%;
DHW productivity at Δt=30 – 8.6 l/min;
country of origin: Italy.

Types of heat exchanger materials – what to choose?

The heat exchanger is the main component of a gas boiler. The coolant is heated in it, so the parameters and design of this unit are of great importance.

For production use:

stainless steel . This is a budget option, although the parameters of steel heat exchangers allow you to get quite effective results. Typically, such units are installed on inexpensive medium-power boilers;
copper tube (coil) . This option is used on expensive models of gas boilers. Copper has a high heat transfer coefficient, so the effect of using such heat exchangers is very high;
cast iron. It is resistant to mechanical and thermal loads. For the manufacture of heat exchangers, gray ductile metal is used, which is resistant to changes or different values of liquid temperature at individual points. Massive units help equalize the degree of heating and soften sudden temperature changes.

Copper heat exchangers are considered the most preferable, but steel and cast iron units are also quite functional and can provide high-quality heating of the heating agent.

Ferroli DOMITECH C24

Another compact model produced by Ferroli is the DOMITECH C24. Its height is 700 mm, width – 400 mm, depth – 260 mm. The boiler weighs 27 kg.

This double-circuit device with an open combustion chamber has a power of 24 kW and is capable of heating a room of up to 200 m². It is equipped with a bithermic heat exchanger, as well as multifunctional control and monitoring systems for operational safety. The type of combustion chamber requires the installation of a classic chimney.

Main characteristics of Ferroli DOMITECH C24:

Efficiency=90.5%;
DHW productivity at Δt=30 – 11.1 l/min;
country of origin: Italy.

Convection or condensation?

The traditional method of heat transfer from a gas boiler is heating the coolant in flow mode. It passes through a heat exchanger, and the gas burner heats the liquid according to the specified operating mode.

This type of boiler is called convection boiler. Relatively recently, a new design of units appeared - condensing. It uses preheating of the coolant from the heat released during condensation of the exhaust smoke.

The temperature of the liquid increases by a small amount, but this is enough to reduce the heating mode of the main heat exchanger.

As a result, a positive effect is achieved:

fuel consumption is reduced;
the load on the burner and heat exchanger is reduced;
The service life of the boiler increases.

With properly organized operation of the unit, fuel savings reach 20%. However, there are some specific conditions that sharply limit the scope of application of condensing boilers.

The reason is that the condensation process can only occur when the temperature of the walls of the condensation chamber is higher than the return flow temperature. This is only possible on underfloor heating systems or radiator circuits with a low degree of heating.

It is calculated that the operation of the first stage is possible only if the difference between the outside and inside of the house is no more than 20°. For Russia, such a ratio is simply impossible. If condensation is not possible, the boiler operates as a conventional convection model.

Considering the almost twofold difference in prices, one should weigh the feasibility of such an expensive purchase with its dubious effectiveness.

Bosch Gaz 3000 W ZS 28-2KE

The dimensions of the Bosch Gaz 3000 W ZS 28-2KE are: height – 700 mm, width – 400 mm, depth – 298 mm. Model weight – 30 kg.

This single-circuit unit with an open combustion chamber has a power of 28 kW and is capable of heating an area of up to 250 m². It is equipped with a multifunction display and ionization flame control. The heat exchanger is made of copper. The type of combustion chamber requires the installation of a classic chimney.

Main characteristics of Bosch Gaz 3000 W ZS 28-2KE:

…

Efficiency=90%;
country of origin – Türkiye.

Selection of coolant

Usually two options are used:

water. Experts recommend using distilled water if the volume of the system allows it. This method avoids the formation of lime deposits, but it will not protect against freezing of pipes in winter;
ethylene glycol (antifreeze) . This is a liquid that does not freeze when circulation stops. Contains a set of anti-corrosion additives, does not form scale, and does not have a destructive effect on polymers, rubber, and plastic.

For systems that need to be drained frequently, water is the best and most economical choice. The use of antifreeze is recommended for heating circuits that operate under difficult conditions.

Teplovest KGO-18-S BUDGET

The compact wall-mounted gas boiler Teplovest KGO-18-S BUDGET has a height of 700 mm, a width of 350 mm and a depth of 250 mm. The weight of the unit is record-breakingly small and amounts to 21 kg.

This single-circuit boiler can be equipped with a turbocharged (C) or atmospheric (B) burner. Its power is 20.5 kW, which is enough to heat 150 m². Equipped with a monothermal heat exchanger and can easily replace an old floor-standing boiler in an existing heating system.

Main characteristics of Teplovest KGO-18-S BUDGET:

Efficiency=90%;
gas consumption – up to 2.1 m³/hour;
country of origin – Ukraine.

Note! Most owners buy small wall-mounted boiler models to sew them up in niches or hide them in a closet, while forgetting about the need for repairs. Therefore, during the installation process, space should be left for a specialist to have free access to the heating device.

Which brand of floor-standing gas boiler is better to choose?

On the consumer market you can find domestic and foreign models from different manufacturers. Russian companies produce simple floor-standing gas boilers for the home. Products from foreign suppliers are convenient, but their prices are higher. The review covers the products of the following companies:

Lemax - the products of this company are in great demand due to their quality. Modern Italian and German equipment is used in production.
Protherm - equipment is assembled at factories in Slovakia and Turkey. The first boilers of this company were imported to Russia in 1996.
Siberia – the brand presents a line of devices with different characteristics. The boilers are made using basalt fiber, which is used to insulate spacecraft.
Borinskoe - the company supplies heating equipment to regions of Russia and neighboring countries. The range includes more than 30 models of gas equipment for home heating.
Baxi - today the Italian brand is owned by the BDR Thermea Group corporation. The company produces non-standard heating and hot water supply systems. The quality of the products is confirmed by certificates.
Ferroli is an Italian company that has been producing heating and air conditioning equipment since 1955. Products are supplied to dozens of European countries. The boilers of this company are durable, reliable and safe.
Viessmann is a large international concern that supplies equipment for heating and cooling of premises. The main priority is the technological development of the industry and concern for the environment. Products are supplied to 74 countries around the world.
Buderus , a European manufacturer of heating equipment, began producing the first boilers in 1731. The trademark belongs to Bosch Thermotechnik GmbH. German technology is reliable and efficient.
Alpenhoff is a German company that produces heating equipment. Production and research centers are located in Germany and Slovakia. The products of this company are imported to 30 countries around the world.
Atem - the first equipment of this company was released in 1988. Since then, the brand’s products have become popular in Ukraine and other countries. Heating appliances are included in the IQenergy energy saving program.
Termomax is a Ukrainian company that produces more than 100 thousand products for space heating every year. Simple equipment is in demand among Russian buyers.
Navien , a Korean brand, has been providing comfort and coziness for 40 years, producing high-quality heating equipment. The main goal of the company is to create favorable conditions for the environment. Products are supplied to 35 countries around the world.

The brands have a long history, good reputation and worldwide fame. Domestic manufacturers are valued no less than foreign ones. In addition, delivery of Russian goods is cheaper.

Fondital Antea CTFS 24

One of the smallest wall-mounted gas boilers is the Fondital Antea CTFS 24. Its height is 700 mm, width – 400 mm, depth – 250 mm. It weighs 26 kg.

This dual-circuit model with a closed combustion chamber has a power of 25.5 kW, which is enough to heat 220 m². The boiler is equipped with two separate heat exchangers: the primary one is made of copper, the second one is made of steel. It has a modern control board and a user-friendly user interface.

Main characteristics of Fondital Antea CTFS 24:

Efficiency=93%;
gas consumption – up to 2.7 m³/hour;
DHW productivity at Δt=30 – 11.1 l/min;
country of origin: Italy.

Read how not to make a mistake when choosing a wall-mounted gas boiler?

Find out about the correct selection of the power of a wall-mounted gas unit here. Household wall-mounted gas boilers - features and popular brands.

What is the difference between non-volatile and conventional boilers?

Conventional (volatile) boilers require an electrical supply, without which they cannot operate. The turbofan, circulation pump, and electronic control board require high-quality and stable power supply.

Particularly capricious are control boards, which immediately fail when the current parameters change. Manufacturers claim the ability to withstand large voltage fluctuations, but in practice this is not observed.

At the same time, volatile units have a set of additional capabilities - they can be controlled remotely, integrated into a smart home system, and programmed for some time in advance..

Non-volatile boilers do not have all these additions. They work exclusively with the help of mechanical components and parts, like a regular gas stove.

The design of such units is devoid of all unnecessary components, it is functional and therefore very reliable. In addition, owners of non-volatile boilers do not face the risk of being left without heating in the event of a sudden power outage.

Dilapidated and overloaded networks are a typical phenomenon for remote villages, so the use of independent heating systems is very valuable for many users.

Ferroli FER EASYtech C 24

The Ferroli FER EASYtech C 24 model has the following dimensions: height – 700 mm, width – 400 mm, depth – 230 mm. The boiler weight is 27 kg.

This double-circuit unit with an open combustion chamber has a power of 24 kW and is capable of heating a room of up to 200 m². It is equipped with an enlarged bithermal heat exchanger and modern multifunctional control and monitoring systems for safe operation. The type of combustion chamber requires the installation of a classic chimney.

Main characteristics of Ferroli FER EASYtech C 24:

Efficiency=90.5%;
DHW productivity at Δt=30 – 11.1 l/min;
country of origin: Italy.

Advantages and disadvantages

The advantages of floor-standing boilers include:

no restrictions on the power of the unit;
strength, reliability of all components and parts;
ease of installation;
stability of operation, the ability to maintain a given mode regardless of external conditions;
no 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 it is necessary to connect to a common house chimney

IMPORTANT!

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

TERMET MiniMax DYNAMIC 24 kW (turbo)

The compact boiler TERMET MiniMax DYNAMIC 24 kW (turbo) has a height of 700 mm, a width of 360 mm and a depth of 300 mm. Weight is 28 kg.

This double-circuit unit with an open combustion chamber has a power of 24 kW and is capable of heating an area of up to 200 m². The primary heat exchanger is made of copper, the secondary one is made of stainless steel. The boiler is equipped with a modulating burner, as well as the necessary control systems for safe operation. The type of combustion chamber requires the installation of a classic chimney. Main characteristics of TERMET MiniMax DYNAMIC 24 kW (turbo) :

Efficiency=91%;
DHW productivity at Δt=30 – 11.4 l/min;
gas consumption – up to 2.7 m³/hour;
country of origin – Poland.

How to determine the required power?

Approximately the power of the heating boiler is determined from the calculation: for each square meter of heating area (at a standard room height) 1 kW of heating device power is required.
To this you need to add a margin of about 15%. It is also necessary to take into account the thickness of the walls and the material from which they are built, since the heat retention in the room depends on the thermal conductivity of the walls. The power of the selected boiler also depends on the amount of water in the system and the method of its circulation. If the circulation is forced (using pumps), then less heating power is required.