Is it possible to install a gas boiler less than 5 kW indoors?

How to choose the power of a gas boiler

Most consultants who sell heating equipment independently calculate the required performance using the formula 1 kW = 10 m². Additional calculations are carried out according to the amount of coolant in the heating system.

Calculation of a single-circuit heating boiler

• For 60 m² - a unit of 6 kW + 20% = 7.5 kilowatts can satisfy the need for heat
  . If there is no model with a suitable performance size, preference is given to heating equipment with a large power value.
• In a similar way, calculations are made for 100 m² - the required power of boiler equipment, 12 kW.
• For heating 150 m², you need a gas boiler with a power of 15 kW + 20% (3 kilowatts) = 18 kW
  . Accordingly, for 200 m², a 22 kW boiler is required.

How to calculate the power of a double-circuit boiler

10 m² = 1 kW + 20% (power reserve) + 20% (for water heating)

The power of a double-circuit gas boiler for heating and hot water heating for 250 m² will be 25 kW + 40% (10 kilowatts) = 35 kW
. Calculations are suitable for two-circuit equipment. To calculate the performance of a single-circuit unit connected to an indirect heating boiler, a different formula is used.

Calculation of the power of an indirect heating boiler and a single-circuit boiler

• Determine what volume of the boiler will be sufficient to meet the needs of the residents of the house.
• In the technical documentation for the storage tank, the required performance of the boiler equipment is indicated in order to maintain the heating of hot water, without taking into account the necessary heat for heating. A 200 liter boiler will require an average of about 30 kW.
• The performance of the boiler equipment required for heating the house is calculated.

The resulting numbers are added up. The amount equal to 20% is subtracted from the result. This must be done for the reason that the heating will not simultaneously work for heating and DHW. The calculation of the thermal power of a single-circuit heating boiler, taking into account an external water heater for hot water supply, is done taking into account this feature.

What power reserve should a gas boiler have

• For single-circuit models, the margin is about 20%.
• For two-circuit units, 20% + 20%.
• Boilers with connection to an indirect heating boiler - in the storage tank configuration, the required additional performance margin is indicated.

Calculation of gas demand based on boiler power

In practice, this means that 1 m³ of gas is equal to 10 kW of thermal energy, assuming 100% heat transfer. Accordingly, with an efficiency of 92%, fuel costs will be 1.12 m³, and at 108% no more than 0.92 m³.

The method for calculating the volume of consumed gas takes into account the performance of the unit. So, a 10 kW heating device, within an hour, will burn 1.12 m³ of fuel, a 40 kW unit, 4.48 m³. This dependence of gas consumption on the power of boiler equipment is taken into account in complex heat engineering calculations.

The ratio is also built into the online heating costs. Manufacturers often indicate the average gas consumption for each model produced.

In order to fully calculate the approximate material costs of heating, it will be necessary to calculate the electricity consumption in volatile heating boilers. At the moment, boiler equipment operating on main gas is the most economical way of heating.

For heated buildings of a large area, calculations are carried out only after an audit of the heat loss of the building. In other cases, when calculating, they use special formulas or online services.

Gas boiler - universal heat exchanger, providing circulation of hot water for household purposes and space heating.

The device looks like like a small refrigerator.

When installing a heating boiler, it is necessary to correctly calculate its power.

Installation Requirements

What are the requirements for the installation of such equipment?

The most important thing is the installation of the boiler in a room that does not belong to the "residential" category. Is it possible to place a heater in kitchens and bathrooms? It all depends on whether it will be possible to organize the removal of combustion products outside the house.

If the chimney does not interfere with anything, and at the same time fire safety rules are observed, then it can be installed.

The boiler room must be equipped with a supply and exhaust ventilation system. In this case, the outflow of air should be carried out through the holes under the ceiling, and the inflow - through the holes located no higher than 30 centimeters above the floor level.

Usually for small houses use gas heating boilers power up to 30 kW. Therefore, rooms with a volume of 7.5 cubic meters are suitable for them. If such a boiler is installed in a kitchen or bathroom, then the volume of this room should not be less 21 cubic meters

How to install a boiler in the bathroom

The possibility of installing a gas boiler in the bathroom depends on:

1. The presence of windows here.
2. Boiler options - with an open or closed combustion chamber.

If you decide to install the unit with closed combustion chamber, then the window is not needed. After all, such a device works with the help of a chimney, through which the oxygen necessary to maintain combustion penetrates into the boiler.

If you use the first option, then you can’t do without a window in the bathroom. And if there is none, then it will have to be cut through, whether you like it or not. Otherwise, you will not see permission to connect the boiler to the gas pipe.

And the last is electrical wiring. All modern household boilers are equipped with electronics and automation elements. And they need a reliable and safe wire. Since the bathroom is a humid room, all requirements for wire insulation must be 100% met. And let the master electrician do it.

How to install a boiler in the kitchen

This room is optimal for placing a gas boiler, because:

First, it complies with all norms and requirements.
Secondly, it always has a window, and sometimes even several

At the same time, it is equipped with a window, which is important for ventilation.
Thirdly, the kitchen usually has ventilation.
Fourthly, kitchen walls are often finished with non-combustible materials. But even if there are none, it is enough to finish the installation site of the boiler according to fire safety rules.

Installing a floor boiler

Boilers and automation Ivar The heating equipment market offers two types of gas-fired boilers. Their distinguishing feature is the way they are installed. Hence, there are two types - floor and wall.

The easiest way to install is the floor version. It does not require complex structures. It is enough to make a small podium from a concrete solution or a metal sheet. The main thing is the strength of the base and its incombustibility.The only thing that is required is more space, since floor-standing gas boilers are quite large in size.

Experts advise using a separate room for the outdoor unit. This will not clutter up the main space. In addition, you can make a full-fledged boiler room, where all the nodes of the heating system will be placed.

How is such equipment installed? First install the boiler itself. Then the chimney is connected. Next, the piping of the heating system is made. And the last - connect all this to the water and gas pipes.

Installation of a wall-mounted boiler

Installing a gas boiler In this case, the reliability and safety of installation will depend on the strength of the fasteners fixed on the wall. The small size and weight of the wall analogue made it very popular among the owners of private houses and cottages.

As in the case of the floor option, safety measures must be observed here. If the house is wooden, then it is recommended to close the wall on which the boiler will be hung with a metal sheet.

By the way, this type is very often installed in kitchens, where it is in perfect harmony with furniture and different designs. In addition, the bulk of wall-mounted gas boilers is a complete small boiler room, where there is everything - automation, valves, a circulation pump and other components.

Requirements for a room for installing a gas boiler in a private house

In accordance with the norms of SNiP 42-01 and MDS 41.2-2000, the room in which the gas boiler is installed must comply with the following minimum parameters:

• the area of ​​​​the premises is more than 4 square meters;
• ceiling height - at least 2.5 m;
• room volume - at least 15 m3 (when placed in the kitchen, there are differences described below);
• the presence of a door with a doorway width of at least 800 mm, according to fire safety, the door must open outward;
• the presence of a gap of at least 20 mm under the door;
• the presence of natural light (through a window) at the rate of 0.03 m2 of glazing area for every 1 m3 of room volume (for example, for a room with a volume of 15 m3, the glazing area is 0.03 * 15 = 0.45 m2);
• the presence of ventilation in the boiler room based on the calculation - exhaust in the amount of 3 air exchanges per hour, air inflow - exhaust volume + air required for gas combustion (if the boiler has an open combustion chamber. If there is a closed combustion chamber, combustion air is not taken from the room, and through a coaxial chimney);
• walls separating the room from neighboring ones must have a fire resistance rating of at least 0.75 hours (REI 45) or be covered with a structure with the same fire resistance rating, the fire spread limit must be equal to zero (non-combustible materials);
• the floor in the room is horizontally flat, made of non-combustible material.

Current standards for installing a boiler in the kitchen

According to MDS 41.2-2000, it is allowed to install boilers with a power of up to 60 kW in the kitchen. Gas service workers can often refer to other regulations where a maximum allowable power of 35 kW is indicated, therefore, before installing a boiler with a power of 35÷60 kW, consult your local gas service. Only the power of heating equipment is taken into account, other gas appliances are not taken into account.
Otherwise, in addition to the above requirements for a separate room, there are some differences when placed in the kitchen:

• the minimum volume of the room is at least 15 m3 + 0.2 m3 for each 1 kW of boiler power (for example, when installing a boiler with a capacity of 24 kW, the volume of the room is 15 + 0.2 * 24 = 19.8 m3);
• the window must be openable or equipped with a window;
• the presence of a gap necessary for air flow in the lower part of the door with a cross section of at least 0.025 m2 (Section = Width * Height).

Proper organization of an extension for a boiler room

If it is impossible to allocate a separate room for the boiler room, and you don’t want to install the boiler in the kitchen, the boiler room is simply attached to the outer wall of the house. Also, extensions are relevant in wooden houses, when, after providing the walls with a refractory structure, the dimensions of the room will not meet the minimum standards. The same requirements apply to the extension as for standard boiler rooms, but with some additions:

• the extension must be officially registered; without registration, the gas service simply will not allow connection;
• the boiler room is attached to a blank wall, at a distance of at least 1 meter to the nearest windows and doors;
• extension walls should not be connected with the wall of the house;
• the walls of the extension and the wall of the house itself must comply with a fire resistance limit of at least 0.75 hours (REI 45).

How to calculate the power of a gas heating boiler for the area of ​​\u200b\u200bthe house?

To do this, you will have to use the formula:

In this case, Mk is understood as the desired thermal power in kilowatts. Accordingly, S is the area of ​​\u200b\u200byour home in square meters, and K is the specific power of the boiler - the “dose” of energy spent on heating 10 m2.

Calculation of the power of a gas boiler

How to calculate area? First of all, according to the plan of the dwelling. This parameter is indicated in the documents for the house.Don't want to search for documents? Then you will have to multiply the length and width of each room (including the kitchen, heated garage, bathroom, toilet, corridors, and so on) summing up all the obtained values.

Where can I get the value of the specific power of the boiler? Of course, in the reference literature.

If you don’t want to “dig” in directories, take into account the following values ​​​​of this coefficient:

• If in your area the winter temperature does not fall below -15 degrees Celsius, the specific power factor will be 0.9-1 kW/m2.
• If in winter you observe frosts down to -25 ° C, then your coefficient is 1.2-1.5 kW / m2.
• If in winter the temperature drops to -35 ° C and lower, then in the calculations of thermal power you will have to operate with a value of 1.5-2.0 kW / m2.

As a result, the power of a boiler that heats a building of 200 "squares", located in the Moscow or Leningrad region, is 30 kW (200 x 1.5 / 10).

How to calculate the power of the heating boiler by the volume of the house?

In this case, we will have to rely on the thermal losses of the structure, calculated by the formula:

By Q in this case we mean the calculated heat loss. In turn, V is the volume, and ∆T is the temperature difference between inside and outside the building. Under k is understood the coefficient of thermal dissipation, which depends on the inertia of building materials, door leaf and window sashes.

We calculate the volume of the cottage

How to determine the volume? Of course, according to the building plan. Or by simply multiplying the area by the height of the ceilings. The temperature difference is understood as the "gap" between the generally accepted "room" value - 22-24 ° C - and the average readings of a thermometer in winter.

The coefficient of thermal dissipation depends on the heat resistance of the structure.

Therefore, depending on the building materials and technologies used, this coefficient takes the following values:

• From 3.0 to 4.0 - for frameless warehouses or frame storages without wall and roof insulation.
• From 2.0 to 2.9 - for technical buildings made of concrete and brick, supplemented with minimal thermal insulation.
• From 1.0 to 1.9 - for old houses built before the era of energy-saving technologies.
• From 0.5 to 0.9 - for modern houses built in accordance with modern energy-saving standards.

As a result, the power of the boiler heating a modern, energy-saving building with an area of ​​​​200 square meters and a 3-meter ceiling, located in a climatic zone with 25-degree frosts, reaches 29.5 kW (200x3x (22 + 25) x0.9 / 860).

How to calculate the power of a boiler with a hot water circuit?

Why do you need a 25% headroom? First of all, to replenish energy costs due to the "outflow" of heat to the hot water heat exchanger during the operation of two circuits. Simply put: so that you do not freeze after taking a shower.

Solid fuel boiler Spark KOTV - 18V with a hot water circuit

As a result, a double-circuit boiler serving the heating and hot water systems in a house of 200 "squares", which is located north of Moscow, south of St. Petersburg, should generate at least 37.5 kW of thermal power (30 x 125%).

What is the best way to calculate - by area or by volume?

In this case, we can only give the following advice:

• If you have a standard layout with a ceiling height of up to 3 meters, then count by area.
• If the ceiling height exceeds the 3-meter mark, or if the building area is more than 200 square meters - count by volume.

How much is the "extra" kilowatt?

Taking into account the 90% efficiency of an ordinary boiler, for the production of 1 kW of thermal power, it is necessary to consume at least 0.09 cubic meters of natural gas with a calorific value of 35,000 kJ/m3. Or about 0.075 cubic meters of fuel with a maximum calorific value of 43,000 kJ/m3.

As a result, during the heating period, an error in calculations per 1 kW will cost the owner 688-905 rubles. Therefore, be careful in your calculations, buy boilers with adjustable power and do not strive to "bloat" the heat generating capacity of your heater.

We also recommend seeing:

• LPG gas boilers
• Double-circuit solid fuel boilers for long burning
• Steam heating in a private house
• Chimney for solid fuel heating boiler

Procedure for replacing gas appliances

The legislation provides for certain rules for replacing a gas boiler in a private house. This procedure should be carried out in the following steps:

• With a technical passport for a new gas boiler, they contact the gas supply company to obtain technical conditions.
• After considering the application, the organization issues technical specifications: if the characteristics of the new boiler are similar to the old one, then you only need to obtain a chimney pipe inspection certificate; if the location of any element of the system changes, then it is necessary to order a new project in a specialized organization; if the unit will have a large capacity, then it may be necessary to renegotiate the contract for the supply of gas.
• Now you can conclude an agreement to replace the gas boiler with a specialized organization.You need to get a building permit from them.
• All collected documents are submitted to the gas service for a permit.
• Obtaining permits.

It happens that the gas service does not give permission for a replacement, but the reasons for the refusal are always indicated. In this case, you should correct the comments identified by the gas service and submit the documents again.

…

When replacing one model of a gas boiler with another, keep in mind the following:

• models with an open combustion chamber can only be placed in specially equipped boiler rooms; to remove smoke, a classic chimney is required;
• boilers with a closed combustion chamber with a power of up to 60 kW can be placed in any non-residential premises (kitchen, bathroom, hallway) with an area of ​​at least 7 m²;
• the room where the unit will be located should be well ventilated and have an opening window.

Accommodation Requirements

These requirements will apply directly to the room in which the gas boiler should be placed. What does the instruction manual say about this? So, the room should have a total area of ​​​​more than 7.5 m². Ceiling height - at least 2.2 m.

Scheme of a gas boiler from Vaillant.

In addition, the room must have a window, which, if necessary, can be opened. It must go outside. This is required by fire safety.

As for the door in this room, it should open in the direction of movement from the room. There should be no switches in the room itself. They should be moved outside the room.

A ventilation system (supply and exhaust) is required. Approximately 15 m² of air is needed per 1 m² of gas burned. You also need three air changes.

When installing the boiler itself in the room, fire safety precautions must be strictly observed. So, from the boiler to the combustible elements of the room, a distance of at least 25 cm must be measured. As for fireproof elements, a distance of 5 cm is allowed here.

The distance between the chimney and combustible parts is 40 cm, and between the chimney and non-combustible parts - 15 cm.

The gas boiler must be installed on a perfectly flat surface, on which no slopes are observed.

This is important for safe use

Requirements for boiler rooms for the installation of solid and liquid fuel boilers

The requirements for volume, dimensions and materials for the boiler room are the same. However, there are several specific ones that are associated with the need to organize a chimney and a place to store fuel. Here are the basic requirements (mostly they are written in the boiler passport):

• The cross section of the chimney must not be less than the diameter of the boiler outlet pipe. It is not allowed to reduce the diameter along the entire length of the chimney.
• It is necessary to design a chimney with the least number of elbows. Ideally, it should be straight.
• At the bottom of the wall there should be an inlet (window) for air to enter. Its area is calculated from the power of the boiler: 8 sq. see per kilowatt.
• The outlet of the chimney is possible through the roof or into the wall.
• Below the chimney inlet there should be a cleaning hole - for revision and maintenance.
• The chimney material and its connections must be gas-tight.
• The boiler is installed on a non-combustible base. If the floors in the boiler room are wooden, a sheet of asbestos or mineral wool cardboard is laid, on top - a sheet of metal. The second option is a brick podium, plastered or tiled.
• When using a coal-fired boiler, the wiring is only hidden; laying in metal pipes is possible. Sockets must be powered by a reduced voltage of 42 V, and switches must be sealed. All these requirements are a consequence of the explosiveness of coal dust.

Please note that the passage of the chimney through the roof or wall must be made through a special non-combustible passage

Oil fired boilers are usually noisy

It is worth saying a few words about liquid fuel boilers. Their work is usually accompanied by a fairly high level of noise, as well as a characteristic smell. So the idea of ​​​​putting such a unit in the kitchen is not the best idea. When allocating a separate room, you should make sure that the walls give good sound insulation, and the smell does not penetrate through the doors. Since the internal doors will still be metal, take care of the presence of a high-quality seal around the perimeter. Perhaps the noise and smells will not interfere. The same recommendations apply to attached boiler houses, although they are less critical.

Boiler power determination

Having decided on the type of boiler, it is necessary to calculate its power. You can order a heat engineering calculation that will determine the heat loss of your premises. Based on this figure, you can accurately select the power of the boiler. But you can do without calculation: use the norms determined empirically. Usually per 10 m2 of heated area requires 1 kW of power unit, but then add a “margin” to this power for various types of losses.

The power of the boiler depends on the area of ​​the heated room and heat loss.

Consider an example. If the apartment is 56 m2, you will need a 6 kW unit for heating.If you are going to heat water with it, you need to add another 50%. It turns out that 9 kW of power is required. Just in case, you need to add another 20-30% (in case of abnormal cold weather). Total - 12 kW. But this is for central Russia. If you live further north, you need to increase the power of the boiler. How specific depends on how insulated your house is. If it is a panel or brick high-rise building, 50% or even more will not be superfluous. When choosing the power of the boiler, the main thing is to take it with a margin: if the performance is not enough, the equipment will work at the limit of its capabilities, and this is far from the best mode, which will lead to premature wear and failure. So we do not regret: the difference in the cost of equipment when changing capacities is not very large, but comfort will be guaranteed to you. There will be no excess gas consumption if you buy an automated boiler (namely, such models are the most economical) - the consumption depends on the heat loss in your premises and system parameters, and not on the boiler power. So from this side, the margin of productivity is not a hindrance.

Equipment types

Electric storage heater

In order for a bathroom with a gas water heater to be comfortable, you need to choose and install the device correctly. There are not so many types of equipment:

Choosing a bathroom heater Types and possibilities of modern heating batteries

• a storage water heater is a boiler in the bathroom, made like a boiler. It has a capacious reservoir, inside which heating elements are located. When boiling water is consumed, the tank is again filled with water from the water supply system, the heating is monitored by automation, preventing overheating and boiling of water.Machines of this type are floor and wall;
• flow gas boiler in the bathroom - a design with a heat exchanger that heats water at the expense of a geyser in a matter of minutes. Reliability, economy, simplicity - these are the main advantages of this type of product. The automatic ignition system guarantees complete combustion of gas vapors (98%), which is necessary to prevent any trouble.

Flow type gas heater for bathroom

When buying a device, it is important to consider power. The boiler in the bathroom can be:

• low-power (9-11 kW);
• medium power (17-20 kW);
• extra-powerful (23-25 ​​kW and above).

Modern appliances allow you to regulate the heating. The adjustment knobs are located on the column panel, in addition, there is a display where all values ​​​​are indicated. The recommended temperature is not more than 60 degrees. With an increase in heating, the process of salt deposition is accelerated, which can lead to an early breakdown of the structure.

Requirements for installing a boiler in an apartment

How to install a double-circuit gas boiler in an apartment? Often the installation of such equipment is difficult for a number of reasons (lack of a central gas pipeline, difficulties in obtaining permission, lack of conditions, etc.). To register, knowledge of the laws and basic rules is required. In case of unauthorized installation of a gas heating boiler, you will have to pay a large fine and dismantle the boiler. You need to start by getting permission.

Required documents

To mount the boiler in an apartment with existing central heating, you need to collect a package of documents and go through several authorities in stages:

1. After submitting an application to the state supervision authorities, if the conditions for installation and maintenance of the heating device are met, technical specifications are issued, which are a permit for the installation of equipment.
2. After receiving the conditions, a project is created. It can be performed by an organization that has a license for this type of activity. The best choice would be a gas company.
3. Obtaining permission to enter the boiler. It is issued by inspectors of companies that check ventilation. During the inspection, an act will be drawn up with instructions that need to be eliminated.
4. After collecting all the documents, the design documentation for the installation of the boiler in a separate apartment is coordinated. Within 1-3 months, employees of state supervision must complete the coordination of installation. If no violations are found during the collection and preparation of documents, the consumer receives a final license for the installation.
5. Documents for refusal of service are submitted to the company providing heat supply services.

You can't break the rules. Only the fulfillment of all conditions will allow obtaining permission to installation of gas equipment.

boiler room requirements

The room in which the boiler is installed must meet the following requirements:

1. Gas equipment can only be installed in non-residential premises with tightly closed doors. For installation, do not use the bedroom, utility rooms, kitchens and toilets.
2. It is best to install a gas meter in the kitchen. In this case, an additional pipe is introduced into the room.
3. All surfaces (walls and ceiling) in the room must be lined with refractory materials. It is advisable to use ceramic tiles or gypsum fiber sheets.
4. The area of ​​the room for installation must be at least 4 m2. It is required to provide access to all nodes of the gas boiler for high-quality maintenance of the system.

Chimney installation

Heating installation on gas in apartments allowed only with normally functioning ventilation and combustion products removal system. Therefore, it would be optimal to use a boiler with a closed combustion chamber, which is connected to a horizontal pipe for smoke removal. In this case, it will not be necessary to carry out several pipes for ventilation and smoke removal.

If several owners in the house want to switch to individual heating at the same time, the chimneys are combined into a single cluster. One vertical pipe is attached outside, to which the horizontal pipes coming from the apartments are connected.

For normal operation of the system, it is necessary to install devices for air circulation with high throughput in the boiler room. Such ventilation should be installed separately, without contact with the general one.

Switching to individual heating: advantages and disadvantages

Switching from central heating to gas requires a lot of money and labor. It takes a lot of time to issue permits, so you need to plan and start collecting the necessary papers long before the proposed installation.

The majority of representatives of state structures will prevent disconnection from the centralized heating. Permits are issued reluctantly. Therefore, problems with paperwork are the main drawback in the transition to gas heating.

Switching cons:

1. Unsuitability of the apartment for the installation of individual heating systems.To obtain a permit, a number of steps must be completed. Partial reconstruction costs a lot.
2. Heating appliances require grounding. It is difficult to do this in an apartment, since according to SNiP it is impossible to use water pipes or an electrical network for this.

The main advantage of such heating is efficiency and profitability. The cost of re-equipment pays off in a few years, and the consumer receives energy independence.

Finished construction

Place for installation of a gas boiler

Speaking specifically about apartments, they install gas boilers in them mostly in the kitchens. There are all the necessary communications: water supply, gas, there is a window and an extractor hood. It remains only to determine a suitable place for the boiler. For such an installation, wall-mounted (mounted) boilers are used. They are mounted on several hooks attached to the walls (they usually come with the kit).

As for installation in other rooms of an apartment or house, as a rule, none of them meets the requirements. For example, the bathroom does not have a window with natural light, the corridor usually does not fit in size - there are not enough tolerances from the corners or to the opposite wall, there is usually no ventilation at all or it is not enough. With pantries the same trouble - there is no ventilation and windows, there is not enough volume.

The exact distance from walls and other objects is indicated in the boiler operating instructions.

If there are stairs to the second floor in the house, the owners often want to put the boiler under the stairs or in this room. In terms of volume, it usually passes, and ventilation will have to be made very powerful - the volume is considered to be in two levels and it is necessary to ensure its triple exchange.This will require several pipes (three or more) of a very large cross section (at least 200 mm).

After you have decided on the room for the installation of a gas boiler, it remains to find a place for it. It is selected based on the type of boiler (wall or floor) and the requirements of the manufacturer. The data sheet usually details the distances from the wall to the right / left, the installation height relative to the floor and ceiling, as well as the distance from the front surface to the opposite wall. These may vary from manufacturer to manufacturer, so read the manual carefully.

Installation standards according to SNiP

In the absence of such recommendations in the equipment passport, the installation of a gas boiler can be carried out according to the recommendations of SNiP 42-101-2003 p 6.23. It says:

• Gas boilers can be installed on fireproof walls at a distance of at least 2 cm from it.
• If the wall is slow-burning or combustible (wooden, frame, etc.), it must be protected by fireproof material. This may be a three-millimeter sheet of asbestos, on top of which a sheet of metal is fixed. Plastering with a layer of at least 3 cm is also considered as protection. In this case, the boiler must be hung at a distance of 3 cm. The dimensions of the fireproof material must exceed the dimensions of the boiler by 10 cm from the sides and bottom, and from above must be 70 cm more.

Questions may arise regarding the asbestos sheet: today it is recognized as a material hazardous to health. You can replace it with a layer of mineral wool cardboard. And keep in mind that ceramic tiles are also considered a fireproof base, even if they are laid on wooden walls: a layer of glue and ceramics just give the required fire resistance.

A gas boiler can be hung on wooden walls only if there is a non-combustible substrate

The installation of a gas boiler relative to the side walls is also regulated. If the wall is non-combustible, the distance cannot be less than 10 cm. For combustible and slow-burning, this distance is 25 cm (without additional protection).

If a floor standing gas boiler is installed, the base must be non-combustible. A non-combustible stand is made on a wooden floor. It must provide a fire resistance limit of 0.75 hours (45 minutes). This is either bricks laid on a spoon (1/4 of a brick), or thick ceramic floor tiles that are laid on top of an asbestos sheet fixed to a metal sheet. The dimensions of the non-combustible base are 10 cm larger than the dimensions of the installed boiler.