It should be your desire, when installing a condensing gas heating boiler, to follow the latest achievements in design ideas. The point is that ordinary gas boilers, without which no serious system is unthinkable autonomous heating country house, do not fully utilize the full potential of an energy source such as gas. That's why even best models gas heating boilers have an efficiency of no higher than 80%. Some of the energy has to be removed outside and simply thrown out through the collector.

Devices beyond school physics postulates

But there is an opportunity to squeeze additional dividends out of gas in the form of kilocalories of energy.

The essence of the process

The idea lies in the following postulates:

• gas is a non-uniform heat source, it also contains water vapor;
• turns out, When we burn gas, we emit not only combustion products, but also this very steam;
• and an idea arises - why not condense this steam and use the resulting hot water to heat the coolant in the heating system.

And so it was done - the newest gas heating boilers condensation type. Boilers are gaining popularity so widely that, according to statistics, more than 30% of all gas boilers in Germany are compensation ones.

Born at a time when increased demands began to be placed on products created in the world in terms of design, condensing boilers are developed with an emphasis on this characteristic - they all look terribly attractive.

Well, what is hidden inside, thanks to this “double purification” of the gas, allows us to achieve a real calculated efficiency of 105 to 110%. In other words, condensing boilers, in essence, are double-circuit boilers.

Useful advice! Unfortunately, we cannot say that the boilers we present are as widespread as in Germany. Therefore, if you decide to install such a boiler in your home, first of all choose a worthy model, and most importantly, a worthy supplier and adjuster of the purchased boiler. Frankly speaking, the vast majority of companies have neither experience working with such boilers nor the appropriate personnel for its further maintenance.

Advantages of condensing boilers

The advantages include the following:

• they have the maximum efficiency of all possible devices for a similar purpose - which means you have the opportunity to reduce gas consumption with the same calories of generated energy; according to statistics, gas consumption in condensing boilers is 15-20% less than in conventional boilers;

• a much larger range of adjustment of the coolant temperature - such adjustment is possible on all boilers, but those operating with gas and “associated” steam have a maximum range from 30 to 85 degrees (by the way, such a maximum, as a rule, is not necessary to supply to the system, the usual coolant temperature in heating systems does not exceed 40 degrees);

• smaller output harmful substances into the atmosphere - the gas mixture burns in a much larger volume;

• innovative technology spurs both designers and technologists - all condensing boilers are manufactured to the highest standards advanced technologies, which provides them with a much longer service life under the same loads.

Among the shortcomings

But we must be aware that such boilers also have some disadvantages, more of an everyday kind:

• the most important thing is that they cost at least twice as much as conventional gas boilers; and this is today the main obstacle to their mass use;

• secondly, such units are very picky about the material from which the chimney is made - it is necessary to use only high-quality plastic and ceramics;

• thirdly, it requires a special calculation of the heating system for lower internal temperatures (not higher than 70 degrees) - this requirement already puts forward the need for steam condensation inside;

• fourthly, a special water pipeline is required to discharge outside, usually into the sewer, the water accumulated inside (usually no more than 30 liters per day with constant operation of the boiler); here it should be noted that in Germany, for example, there are restrictions on the discharge of such water into the general sewer system;

• fifthly, it requires experienced personnel to install and maintain them.

Despite the fact that these boilers were initially designed as double-circuit boilers, there are also single-circuit models. But most importantly, several modifications of condensing boilers have been developed depending on the location of their installation.

There are modifications:

• floor– the most powerful and widespread; the power of such boilers can be 100-120 kW;
• - very elegant-looking devices with a power of 30-40 kW, which is often more than enough.

Useful advice! If you decide to purchase a gas condensing boiler for industrial use, most likely you will need to choose a model of direct, or they also say, “wet” effect on the coolant flow. The efficiency of such boilers is even higher, but their use is still limited to a small supply market. At home, boilers that have an indirect, or “dry” effect on the coolant, without contact with it, are widely used.

On the crest of a wave

You are unlikely to succeed with your own hands. This is too important technology, serving too important tasks. Even though you will have installation and operating instructions at your disposal, even though you will view all the photo and video materials on our website, you will still have to seek detailed advice from professionals.

But to understand the algorithm of operation of condensing boilers and choose the necessary one, according to power and appearance, this is already for you. In any case, take your choice very responsibly, the price of a mistake is quite high and is expressed not only in the quality of heating of your home, in considerable lost financial resources, but also in discrediting such an important thing as the introduction into our lives of the most advanced achievements of designers and designers .

Users of our portal have a unique opportunity to follow how, as part of the project with FORUMHOUSE, we, with our partners, are building a comfortable and energy-efficient country house in the Moscow region. For this purpose, when constructing a cottage, the most modern materials and technology.

USHP was chosen as the foundation, and the heating system was underfloor heating. In addition, the boiler room was equipped with a wall-mounted condensing gas boiler. A technical specialist from the company will tell you in a master class format why this particular equipment was chosen for our project and what the advantages of its operation are.

• Operating principle of a condensing gas heat generator.
• Advantages of using a condensing gas boiler.
• In which heating system is it best to use this equipment?
• What to pay attention to when operating a condensing gas boiler.

Operating principle of a condensing gas heat generator

Before we talk about the nuances of condensation technology, we note that an energy-efficient, and therefore comfortable and economical, country house is a balanced structure. This means that, in addition to the closed thermal insulation loop, all elements of the cottage, including engineering system, must be optimally matched to each other. Therefore, it is so important to choose a boiler that combines well with a low-temperature underfloor heating system, and will also reduce energy costs in the long term.

Sergey Bugaev Ariston technical specialist

In Russia, unlike European countries, condensing gas boilers are less common. In addition to environmental friendliness and greater comfort, this type equipment allows you to reduce heating costs, because such boilers operate 15-20% more economically than conventional ones.

If you look technical specifications condensing gas boilers, then you can pay attention to the efficiency of the equipment - 108-110%. This contradicts the law of conservation of energy. While, indicating the efficiency of a conventional convection boiler, manufacturers write that it is 92-95%. Questions arise: where do these numbers come from, and why does a condensing gas boiler work more efficiently than a traditional one?

The fact is that this result is obtained thanks to the thermotechnical calculation method used for conventional gas boilers, which does not take into account one important point evaporation/condensation. As is known, during the combustion of fuel, for example, main gas (methane CH 4), thermal energy, and carbon dioxide (CO 2), water (H 2 O) in the form of steam and a number of other chemical elements are also formed.

In a conventional boiler the temperature flue gases after passing through the heat exchanger it can reach 175-200 °C.

And water vapor in a convection (ordinary) heat generator actually “flies into the chimney,” taking with it part of the heat (generated energy) into the atmosphere. Moreover, the amount of this “lost” energy can reach up to 11%.

To increase the efficiency of the boiler, it is necessary to use this heat before it is lost and transfer its energy through a special heat exchanger to the coolant. To do this, you need to cool the flue gases to the so-called temperature. “dew point” (about 55 °C), at which water vapor condenses and useful heat is released. Those. - use the energy of phase transition to maximize the use of the calorific value of the fuel.

Let's return to the calculation method. Fuel has a lower and higher calorific value.

• The gross calorific value of a fuel is the amount of heat released during its combustion, taking into account the energy of water vapor contained in the flue gases.
• The net calorific value of a fuel is the amount of heat released without taking into account the energy hidden in water vapor.

The boiler efficiency is expressed in the amount of thermal energy obtained from fuel combustion and transferred to the coolant. Moreover, by indicating the efficiency of a heat generator, manufacturers can by default calculate it using the method using the lower calorific value of the fuel. It turns out that real coefficient useful action convection heat generator is actually about 82-85% , A condensation(remember the 11% additional heat of combustion that it can “take away” from water vapor) – 93 - 97% .

This is where condensing boiler efficiency figures appear that exceed 100%. Due to its high efficiency, such a heat generator consumes less gas than a conventional boiler.

Sergey Bugaev

Condensing boilers provide maximum efficiency if the coolant return temperature is less than 55 °C, and these are low-temperature heating systems “warm floors”, “warm walls” or systems with an increased number of radiator sections. In conventional high temperature systems the boiler will operate at condensation mode. Only in severe frosts will we have to maintain a high temperature of the coolant; the rest of the time, with weather-dependent regulation, the temperature of the coolant will be lower, and due to this we will save 5-7% per year.

The maximum possible (theoretical) energy savings when using condensation heat is:

• during combustion natural gas – 11%;
• during combustion liquefied gas(propane-butane) – 9%;
• when burning diesel fuel (diesel fuel) – 6%.

Advantages of using a condensing gas boiler

So, we have dealt with the theoretical part. Now we’ll tell you how the design features of a condensing boiler affect its operating efficiency and durability. At first glance, it seems that it is possible to use the additional energy of water vapor hidden in the flue gases in a conventional boiler, specially “driving” it into a low-temperature operating mode. For example, by connecting the boiler (this is incorrect) directly to the underfloor heating system or by significantly lowering the temperature of the coolant circulating in the radiator heating system. But, we already wrote above that during the combustion of main gas, a whole “bouquet” of chemical elements is formed. Water vapor contains: carbon dioxide and carbon monoxide, nitrogen oxides, as well as sulfur impurities. During condensation and the transition of steam from a gaseous to a liquid state, these impurities end up in water (condensate) and the output is a weak acidic solution.

Sergey Bugaev

The heat exchanger of a conventional boiler will not withstand prolonged operation in an aggressive chemical environment; over time, it will rust and fail. The condensing boiler heat exchanger is made of materials that are corrosion resistant and resistant to acidic environments. The most resistant material is stainless steel.

In the manufacture of the condensing boiler, only durable and wear-resistant materials are used. This increases the service life and reliability of this equipment, and also reduces maintenance costs.

In addition, increased requirements are placed on other structural elements of the condensing heat generator, because it is necessary to cool the flue gases to the required temperature. For this purpose, the boiler is equipped with a forced-air burner with a high degree of modulation. This burner operates in a wide power range, which allows you to optimally regulate water heating. Condensing boilers are also equipped with automatic equipment that ensures precise maintenance of the combustion mode, temperature of the exhaust gases and water in the return line. Why are circulation pumps installed that smoothly change the pressure force of the coolant flow, and not as simple 2- and 3-speed pumps? With a conventional pump, the coolant flows through the boiler at a constant speed. This leads to an increase in the temperature in the “return”, an increase in the temperature of the flue gases above the dew point, and, consequently, a decrease in the efficiency of the equipment. It is also possible for the heating system (warm floor) to overheat and reduce thermal comfort.

Important nuance: the burner of a conventional boiler cannot operate at a power lower than 1/3 of the maximum (rated) power of the heat generator. The condensing boiler burner can operate at a power of 1/10 (10%) of the maximum (rated) power of the heat generator.

Sergey Bugaev

Consider the following situation: started heating season, outside temperature -15 °C. The power of a conventional boiler installed in a house is 25 kW. The minimum power (1/3 of the maximum) at which it can operate is 7.5 kW. Let's assume that the building's heat loss is 15 kW. Those. The boiler, continuously operating, compensates for these heat losses, plus there remains a power reserve. A few days later there was a thaw, which, you see, often happens during the winter. In the end outside temperature now around 0°C or slightly below. The heat loss of the building, due to the increase in outside temperature, has decreased and is now approximately 5 kW. What will happen in this case?

An ordinary boiler will not be able to working continuously, produce the 5 kW of power necessary to compensate for heat loss. As a result, it will go into the so-called cyclic mode of operation. Those. the burner will constantly turn on and off, or the heating system will overheat.

This mode is unfavorable for the operation of the equipment and leads to its accelerated wear.

A condensing boiler, with the same power and in a similar situation, in continuous operation will quietly produce 2.5 kW of power (10% of 25 kW)¸ which directly affects the service life of the heat generator and the level of comfort in a country house.

The condensing boiler, complemented by weather-dependent automation, flexibly adapts to changes in temperature throughout the heating season.

Modern automation makes it possible to significantly simplify the process of boiler control, including remotely, using a special mobile application for smartphones, which increases the ease of use of the equipment.

Let us add that the heating season in Russia, depending on the region, is on average 6-7 months, starting in the fall, when it is not very cold outside, and lasting until spring.

Approximately 60% of this time, average daily temperatures outside remain around 0 °C.

It turns out that the maximum boiler power may be required only in a relatively short period of time (December, January), when real frosts have set in.

In other months, the boiler is not required to reach maximum operating mode and increase heat output. Consequently, a condensing boiler, unlike a conventional one, will work effectively even with temperature changes and slight frost. At the same time, gas consumption will be reduced, which, in tandem with a low-temperature heating system (warm floor), will reduce the cost of purchasing energy.

Even when using a condensing boiler together with high-temperature radiator heating, this equipment works 5-7% more efficiently than traditional ones.

Sergey Bugaev

In addition to being economical, an important advantage of condensing boilers is the ability to obtain high power with compact equipment sizes. A wall-mounted condensing gas boiler is especially relevant for small boiler houses.

In addition, the condensing boiler has a turbocharged burner, which allows you to abandon the standard expensive chimney and simply remove the coaxial chimney pipe through a hole in the wall. This simplifies the installation of equipment or the installation of a new condensing boiler to replace the old - conventional one, when renovating an existing heating system.

Features of operation of a condensing gas boiler

Frequently asked questions from consumers: what to do with the condensate obtained during the operation of the boiler, how harmful it is, and how to dispose of it.

The amount of condensate can be calculated as follows: per 1 kW*h there are 0.14 kg. Consequently, a condensing gas boiler with a power of 24 kW when operating at 12 kW of power (since most of the heating period the boiler operates with modulation, and the average load on it, depending on conditions, can be below 25%) on a fairly cold day produces 40 liters of condensate at low temperature.

Condensate can be drained into the central sewer, provided that it is diluted in a ratio of 10 or better 25 to 1. If the house is equipped with a septic tank or local wastewater treatment plant, condensate neutralization is required.

Sergey Bugaev

The neutralizer is a container filled with marble chips. Filler weight – from 5 to 40 kg. It must be changed manually on average once every 1-2 months. The condensate, usually passing through the neutralizer, flows by gravity into the sewer system.

Summing up

This is modern equipment that is reliable, economical and efficient. Emissions of harmful substances into the atmosphere are also reduced, which is especially important when environmental standards are tightened. In addition, installation of this type a heat generator, by reducing gas consumption, will reduce heating costs in the long term and increase the level of comfort in a country house.

E. Chernyak

To ensure that the consumer remembers the boiler only during scheduled maintenance, it is not enough to simply choose high-quality and reliable equipment. It is important to install it correctly, because often illiterate installation leads to failure of the equipment and a ban on its delivery to warranty service. This is especially true when installing expensive condensing equipment

General principles

Collateral correct installation boiler and its further normal operation is the competent design of the entire heating system. The point is that, for example, significant efficiency and operating comfort of equipment cannot be achieved without installing thermostats. Modern technologies make it possible to create zoned heating systems. In this case, each heating zone maintains its own microclimate under the control of a room temperature sensor.

The temperature of the condensation heat exchanger must be below the dew point of the exhaust gases, and the formation of chemically active liquid condensate on its surface is not only normal, but also necessary. Moreover, it must be diverted outside and neutralized in one way or another. Combustion product exhaust systems must be made of corrosion-resistant materials.

When installing systems with condensing boilers, it is important to accurately calculate the heat loss of the building and design heating taking into account the use of such equipment.

To reduce the required coolant temperature, additional measures to reduce heat loss are important - thermal insulation of enclosing structures, installation of windows with multi-layer glazing.

Boiler space

Guided by regulatory documents, determine a suitable room. At the same time, options for installing a boiler in bedrooms, bathrooms, common-use corridors, rooms with insufficient ceiling height, small volume and absence of windows (transoms, vents) are not accepted in advance. Most suitable places are kitchen or separate non-residential premises of sufficient volume, with opening windows or vents (Fig. 2). The presence of sewerage in the premises is highly recommended.

Rice. 2. The boiler room must have opening windows

When hanging the boiler on the wall, you usually use the hooks included in the delivery kit. They are fixed to the wall using dowels. Then the unit itself is hung on these hooks. It is unacceptable if the upper edge of the boiler is further away from the wall than the lower edge, that is, in common parlance, “filled up.” For a traditional boiler, a forward tilt of 0.5-1.0 cm per 1 m does not pose a significant danger, but in the case of a condensing boiler the situation is different. After all, the condensation module is rigidly fixed to the frame. During boiler operation, condensation of water vapor from combustion products occurs in the secondary chamber of the module (economizer section). The resulting condensate is collected in a molded tray and discharged first into a siphon and then into the sewer (Fig. 3).

Rice. 3. Formation and removal of condensate from the condensing boiler module

When the top of the boiler tilts forward, the condensate flows into the primary chamber, comes into contact with the heat exchanger tubes and begins to evaporate intensively. This leads to the short circuit of the flame control electrodes to the boiler body and its blocking.

Thus, when attaching the boiler to standard hooks, it is necessary to carefully check the verticality of the boiler and, if necessary, level it. The boiler tilting forward is unacceptable. Also, the boiler must not tilt to the side.

Deviations from the vertical position are checked using a level gauge.

Requirements for chimneys

Most errors during the installation of condensing boilers occur due to violation of the manufacturer’s recommendations or neglect of smoke removal standards.

Violations often occur due to the use of coaxial pipes or separate sets from traditional boilers. The material for the manufacture of coaxial pipes of traditional boilers is aluminum alloys and steel. Their purpose is to withstand high temperatures of combustion products (110°C and above). The specificity of the operation of condensing boilers is low flue gas temperatures in standard modes (40 - 90 ° C), and often below the dew point temperature (57 - 60 ° C, depending on the excess air coefficient). Condensation of water vapor from combustion products occurs not only in the boiler module, but also in the chimney. Condensate has low acidity at pH=4, but with prolonged exposure to aluminum or steel chimney ducts it can destroy them. Therefore, the chimneys of condensing boilers along the exhaust path are made of special polymers (for example, polypropylene) that are resistant to acid corrosion of condensate and can withstand temperatures up to 120°C. For example, the Baxi company (Italy) supplies for its condensing boilers (Fig. 4), the efficiency of which is 108.9%, a plastic coaxial pipe with a tip with a diameter of 60/100 mm and a length of 750 mm. The delivery set includes: coupling and gasket; tip protecting against gusts of wind; decorative stainless steel trim for the outer part of the wall.

Rice. 4. Wall-mounted gas condensing boiler

The use of chimney kits from traditional boilers on condensing boilers and vice versa is prohibited.

There are also violations due to the use of sewer pipes as chimneys. Due to the rather high cost of special chimneys for condensing boilers, there is often a temptation to use sewer pipes, because low temperature flue gas is one of the features of such boilers. The mistake is that sewer pipes are not designed for long-term operation at high temperatures (80°C and above). And the flue gas temperature may be higher than this value, for example, when the boiler is operating in DHW mode. In this case, the sewer pipes are deformed, the sealing rings dry out and crack, and the chimney tract ceases to be tight. At the same time, people's lives are at risk and damage is caused to chimneys due to their soaking from condensation and gradual destruction. In this regard, the use of sewer pipes as chimneys for condensing boilers is unsafe and is strictly prohibited.

Incorrect slope of chimney or air intake pipes. Options for installing chimneys of condensing boilers may vary depending on the conditions (Fig. 5), however, the basic rule must be observed - the slope of the chimney pipe should facilitate the flow of condensate back into the boiler module. The slope of the air intake pipe should prevent precipitation from entering the boiler body.

Rice. 5. Options for installing chimneys in accordance with European classification for type C boilers (with combustion air intake from the external space or from a common shaft)

In Fig. 6 schematically shows the correct methods for organizing smoke exhaust and air intake when various types chimney pipes. So, in Fig. 6a shows the use of one chimney pipe and the transfer of the boiler to operation with air intake from the room. The elbows (if any) are assembled in such a way as to ensure that condensate flows through the pipe back into the condensation module. It is very important to avoid possible places with a negative slope, where stagnant condensation will accumulate and disrupt the operation of the fan.

As a special case, a single chimney is used, which exits straight up from the boiler without elbows. If you exhaust combustion products into an existing (or common for multi-story buildings) chimney (Fig. 6 b), then you need to make sure that this chimney can be used with condensing boilers and has a condensate collector with a siphon at the lowest point. Emission of flue gases from condensing boilers in brick chimneys leads to their destruction due to soaking. Release into chimneys made of black steel or aluminum leads to increased corrosion. The most optimal are insulated chimneys made of polypropylene or stainless steel. If the customer has a chimney, for example a brick one, then it can be “lined” with polypropylene pipes or a stainless steel pipe.

When assembling the chimney, it is very important to follow the connection order: into the socket with an o-ring, the next section is inserted from above with the smooth side. This allows condensate to flow unhindered back into the boiler module. But often stainless steel chimneys are assembled from scrap materials, and even with gross violations (the lower pipe enters the socket of the upper one), thus, condensate flowing back through the pipe exits through the connections, which in some cases leads to disastrous results. For example, condensate begins to flood the boiler.

When using a standard coaxial kit, it is also necessary to observe the upward slope of the chimney pipe (Fig. 6 c). For low-power wall-mounted boilers, the slope is ensured by the design of the end terminal - when the outer pipe is horizontal, the inner one has an upward slope.

Structurally, it is possible to install a boiler with a single horizontal discharge behind the wall. The slope, as in the above cases, is upward (Fig. 6 d).

Rice. 6. Organization options correct slopes pipes

In Fig. Figure 7 shows diagrams of improper installation of chimney and air intake pipes. In this case, a stagnant zone may form, which interferes with the operation of the fan and leads to blocking of the boiler (Fig. 7 a). If installed as in Fig. 7 b or fig. 7v, condensate in large quantities flows out and freezes to form icicles. The location of the air intake pipe is as shown in Fig. 7 g will lead to atmospheric moisture entering the boiler body, and then to blocking the boiler or short circuit.

Rice. 7. Incorrect installation of chimney slopes

Despite the fact that both the DBN and the recommendations of the manufacturer strictly regulate the distance from the emission terminal to the nearest objects, gross violations of these standards occur quite often. Among the most common are the low level of the coaxial terminal relative to the ground and the short distance between adjacent terminals.

The first is typical for private cottages. Thus, semi-basement rooms are most often allocated for the boiler and related components of the heating system (pumps, collectors, expansion tanks, boilers, etc.). The choice is obvious and correct - useful living space is not taken away, all components of the system can be hidden and they will not interfere with the design of the premises. After all, placing a bulky boiler with piping and a hot water boiler in the kitchen is not a very aesthetic solution. And although the vast majority of adapted premises have chimney and ventilation ducts, there is a temptation to save on the pipe and, instead of “lining” the existing chimney and installing a separate set for smoke removal and air intake, take the coaxial pipe from the boiler directly through the wall. As a result, the distance from the ground to the terminal is often several times less than the regulated distance. This arrangement, in addition to being dangerous for people, also contributes to the active absorption of ground dust and sand into the boiler fan, and then their entry into the mixing path and combustion chamber. In the future, this can lead to malfunction of the boiler, its premature wear and failure.

The second violation is typical for cascade installation of boilers. In this case, the desire to save money often leads to a reduction in the required distance between terminals or the use of air ducts not intended for such installation. It is clear that without reconstruction of the chimneys it is prohibited to start such boilers and put them under warranty. Therefore, it is best to use kits offered by the boiler manufacturer. (For example, Baxi offers not only chimneys for cascade installations, but also hydraulic accessories and control automation).

Before installing the boiler, it is also necessary to take into account the minimum distances from the flue terminals to the nearest obstacles.

Condensate drainage

The technology by which condensing boilers operate involves the formation of condensate from water vapor contained in combustion products. Depending on the temperature conditions and the power of the installed boiler, the formation of up to 50 l/day is possible. liquid that needs to be discharged into the sewer. The low acidity of the condensate allows it to be drained into the nearest siphon of household waste, which has high alkalinity. As a result of the neutralization reaction, no harm is caused to the environment. But still, the condensate drainage path must be made of materials resistant to acidic environments (polypropylene, PVC).

Among the installation errors is the drainage of condensate to the street. Installers sometimes lead the corrugated pipe directly to the street, similar to a split air conditioning system. In winter, this will lead to blocking of the duct with ice, filling the module with condensate and the boiler going into emergency lockout.

If the sewage level in the house is significantly higher than the boiler, it is necessary to use special condensate pumps with built-in reservoirs, for example Conlift units (Fig. 8), offered by the Danish company Grundfos. They will allow, as condensation forms, to raise it to the desired height and drain it into the sewer.

Rice. 8. Conlift condensate removal unit

Security group

Some models of condensing boilers do not have a built-in expansion tank and safety valve. Therefore, they must be installed during installation. Also in this case, a system filling tap should be provided. It should be located on the supply line after the boiler to prevent cold make-up water from entering the heated heat exchanger of the boiler.

In addition, the following errors occur when installing condensing boilers (typical of traditional heat generators):

• wiring the heating system and piping the boiler with small diameter pipes;
• incorrect gas supply (restriction gas pipeline, use of inappropriate boiler power gas meter, absence gas filters or their illiterate installation, etc.);
• installation of boilers on wooden and other flammable walls without prior protection;
• lack of filters on the boiler return line and at the cold tap water inlet;
• errors in the organization of power supply (there is no voltage stabilizer or relay at the input to the boiler, there is no grounding loop, generators or other power sources are used that do not have a zero phase or produce distorted characteristics, for example, non-sinusoidal voltage).

Connecting the thermostat

A modern energy-efficient heating system is impossible without installing thermostats. After all, as we have already noted, condensing boilers operate most efficiently at low temperatures. And thermostats allow you to more accurately control the boiler gas valve and maintain the coolant temperature at the lowest possible level.

The indoor air temperature regulator CR4, manufactured by Honeywell (USA), uses the OpenTherm digital communication protocol to control the boiler (Fig. 9). This technology means remote control of the burner, in which the boiler produces exactly the amount of heat that is currently required in response to a proportional request from room thermostat. The digital connection used is noise-resistant and protected against incorrect connections and short circuits. Low safe voltages are used. The OpenTherm communication protocol can be used with boilers from various manufacturers.

Rice. 9. Boiler control using a thermostat with a radio module

The CR4 thermostat can be set to a 7-day heating and cooking program hot water. There are 3 adjustable temperature levels and 5 factory heating programs. Provides display of boiler operating modes and fault diagnosis. There is frost protection.

Radio frequency communications are carried out using the band 868.0-868.8 MHz. Communication range: 100 m in open space, 30 m in a typical residential building. The receiving module is installed next to the boiler or inside it and is connected using a two-wire wire.

Advantages remote control using radio communication are that during installation there is no need to lay cables, which is especially important when reconstructing heating systems.

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It's time to consider and understand the features of condensing gas boilers...

Condensing gas boilers: operating principle, types and advantages

Thanks to their high-tech design, condensing boilers make the heating system much more convenient, comfortable, and economical. If in conventional devices combustion products release only part of the thermal energy, then in this case this is done to the maximum. The company "Luch Tepla" presents in large assortment boilers of all types.

Design

In their structure, condensing boilers are indistinguishable from typical heating devices. Available in several options:

1. wall mounted (more traditional, focused on customized systems heating of private residential buildings);
2. floor-standing (high power, intended for use in office and industrial premises).

Their design includes a non-standard heat exchanger made on the basis of acid-resistant materials. Usually made of stainless steel or silumin. It looks like a pipe with a complex cross-section and spiral ribs. All this increases the heat exchange area and makes the gas boiler more efficient.

In addition, the condensation device is equipped with a fan located in front of the burner. It “sucks” gas from the gas pipeline, mixes it with air and directs it directly to the burner. The boiler also has an electronically controlled pump, which allows you to optimize heating power, reduce noise from the coolant flowing through the system and save on electricity.

Types of Condensing Gas Boilers :

Condensing boilers There are several types:

1. single-circuit;
2. double-circuit;
3. heating;
4. water heating.

Moreover, their power can vary from 20 kW to 100 kW, which is quite enough for household boilers. For office and industrial premises they are produced with greater power and in a floor-standing version.

Operating principle of condensing gas boilers :

In standard boilers, the escaping hot gases are simply released into the atmosphere through the chimney duct, losing a significant proportion of unused heat. It is discharged outside along with waste products in the form of water vapor formed during fuel combustion. It is in the steam that additional thermal energy is hidden, which condensing boilers store and then transfer to the heating system.

As the steam cools, it condenses, that is, it becomes a liquid, and releases a certain amount of heat. This process takes place in a special heat exchanger with an expanded area. It is he who “takes” heat for transfer to the heating system. This approach was known before. But they began to use it relatively recently due to the advent of corrosion-resistant alloys, which form the basis for the production of condensing boilers.

Features of operation of CONDENSING gas boilers:

The operating efficiency of such gas devices largely depends on the characteristics of the heating system. The lower the water temperature, the more complete the process of condensation of water vapor occurs. Consequently, the higher the amount of latent heat that is returned to the system.

In this way, the condensation mode is maintained throughout the entire heating period. Therefore, the most important condition for the operation of a condensing boiler is the average temperature of the coolant. For example, at the entrance to the boiler it should be less than 60 degrees (ideally up to 57 degrees). This will give better condensation and increase the efficiency of the heating device.

But even if you combine a condensing boiler with the old system, it will still bring significant savings, since it will be more efficient than the previous equipment. This is due to the fact that in our climate zone the coldest days in total occupy a little more than 10 percent of the duration of the entire heating period. On other days, optimal condensation is possible.

Advantages

Among the basic advantages of this type of boiler is high efficiency. In this case, it is equal to 108-109 percent, when compared with other boilers. Another advantage is their increased efficiency. It is approximately 15-20 percent more than that of standard heating devices.