We disassemble a double-circuit gas boiler: the principle of operation and types of equipment. Installation of a double-circuit boiler according to all safety requirements
- Rules for installing a boiler room in a house
- Dual circuit power supply gas boiler
- Selecting the right unit
- Registration of documents for a gas boiler
- Installation diagram of a two-circuit unit
- Applied materials and tools for the installation of a double-circuit boiler
To organize an autonomous gas heating in a private house suburban area or in a city apartment it is necessary to have special knowledge and independent is undesirable. But if there is no other way, then you can try to install it yourself. First, we agree that in order to maintain a normal temperature regime in the house, out of the whole variety of gas boilers, in our case, only one option is suitable - a double-circuit one. It is carried out by manufacturers in 2 versions - floor and wall. If you do not have a place to install the 1st option, then install the unit of the 2nd type. For a small private house, a gas boiler in the floor version is more suitable - it will be necessary to allocate a separate small room for it.
Before installing a gas boiler, a permit must be obtained.
To install a gas double-circuit boiler, you will need a special permit. If you have enough funds, then you will receive it. An attempt to install a boiler bypassing the authorities will cost you a large amount of a fine. What is such an installation?
This is a home boiler room, which includes the following components:
- double-circuit gas boiler;
- boiler;
- automatic system regulation of parameters;
- double thermostat;
- control microprocessor.
Such a “smart” boiler has a gas consumption of 25-60% less than when using a single-circuit system with manual or semi-automatic control ( gas water heaters). Automation supports the specified temperature regime and reduces heating to a minimum if there is no one in the apartment.
Of course, the dual-circuit system also has a drawback: in the event of a power failure, it causes a malfunction of the automation, and the boiler switches to the minimum space heating mode. To eliminate this shortcoming, it is necessary to incur additional costs for the installation of an autonomous power supply system, which will be discussed below.
Rules for installing a boiler room in a house
Picture 1. .
There are rules according to which the heating boiler, regardless of whether it provides the consumer or not hot water, must be installed in a separate room (furnace). Its area should not be less than 4.5 m², and the height to the ceiling should be at least 250 cm.
The total volume of the boiler room must be at least 8-9 m².
In this room, there must be a window with a window or its fully hinged version. The width of the doorway of the furnace room must exceed 0.9 m. It is impossible to finish the walls of this room with combustible materials and install false ceilings (floors).
For normal air circulation in the boiler room, there must be a through, permanently open eye with a working section of 9 cm² and more per 1 kW of plant power.
If the gas boiler has a closed combustion chamber, then the volume of the boiler room is not standardized. But still, the above dimensions must be observed. The same conditions apply to wall-mounted hot water boilers.
The flue gases of the installation must be discharged to the outside through a separate gas outlet, the use of ventilation systems is not allowed. The length of its horizontal part cannot be more than 3 m and must not have more than 3 turns. The outlet pipe of this branch must be mounted strictly vertically and be raised by 1 m or more in relation to the roof ridge.
There are also requirements for the material of the gas exhaust system: it should not contain heat-resistant, chemically non-aggressive materials.
Figure 2. Scheme of connecting DHW and cold water equipment to an individual boiler house.
If a wall-mounted gas system is installed in the kitchen, then it must be installed with the following conditions:
- the height of the boiler suspension (along its lower part) from the sink must be at least 50 cm;
- from the floor, the installation must be at a distance of at least 0.8 m (along the lower cut);
- lay under the boiler a metal sheet in 1 m².
You can not use asbestos-cement pipes to remove flue gases - SES prohibits the use of materials of this type in an apartment. From the power of the mounted gas system depends on the cross section of the outlet pipe. In any case, it should not be smaller (in diameter) than the outlet pipe of the boiler and be at least 120 mm.
When installing heating pipes, it is necessary to adhere to their positive slope, but it should not be more than 4-5 mm per 1 linear meter of pipe in terms of fluid flow. An air valve is installed at the highest point of the system and expansion tank. According to the rules, the heating system must allow pressing work under pressure (up to 1.8 atm).
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Power supply of a double-circuit gas boiler
The UPS will allow the system to work offline for a while.
The microprocessor and automatic control system used in the design under consideration consume little electricity, but for these purposes they provide separate wiring with a circuit breaker for a current of at least 25 A.
To organize a backup power system, you can use the so-called UPS unit from any computer. With its power of 1 kW, it will maintain the normal operation of automation gas apparatus within 12-18 hours.
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Selecting the right unit
Basically, when choosing a gas boiler, it focuses on the power of the installation. It is impossible to overdo it, since during operation drip condensate is formed, which can fall in the heat exchanger or in the chimney in the form of acid rain and damage the entire system.
If chosen correctly, the temperature in its combustion chamber does not exceed 85-90°C. For orientation in this matter, contact the specialists, but you can also apply the following data (approximate).
Unit power values at minimum/maximum outdoor temperatures (-25/-42°C) are:
Wiring diagram for a separate expansion tank and pump for a floor-standing boiler.
- one-room apartment in the middle part of the house - 9/15 kW;
- corner room 54-60 m² in a block house - 20/30 kW;
- private house with a total area of up to 110 m² - 25/40 kW.
The power is indicated in the instructions for the gas boiler in the form of a fraction, for example 12/18, where the first digit means the heating power under average, normal conditions, and the second - the maximum for the rapid heating of water in the boiler. It is selected depending on the required amount of hot water consumed in the house, and when installing the complete system, the boiler capacity must be at least 150 liters. If you do not use hot water in large quantities, then you can use a boiler with a tank capacity of 50-100 liters.
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Registration of documents for a gas boiler
For complete certainty, you must collect the following documents:
- papers for boiler room equipment according to all requirements;
- technical passport of the gas double-circuit boiler itself;
- a contract with a gas company for the supply of fuel;
- documents for the meter and a certificate for the inlet valve of your installation;
- papers about those changes in the plan of your house (apartment) that will be made during the installation of the unit;
- application to the gas office for the project and specifications of your gas boiler;
- a document on calling a specialist to install and tie the unit;
- application for commissioning the system;
- engineer's conclusion gas service on the suitability and permission to use the gas boiler;
- a document with your signature, stating that the specialist has familiarized you with the rules for operating your device.
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Installation diagram of a two-circuit unit
The contact of the gas boiler with the walls is unacceptable, therefore, the fasteners of wall-mounted boilers cannot be altered and they cannot be installed in a niche. After mounting the unit to the wall, it is necessary to tie it up: turn on the gas network, hot water system and electricity. The work on connecting the gas must be carried out by a specialist, and the rest of the installation can be done independently.
The main typical diagram for connecting a gas boiler to water sources (piping) is shown in Figure 1.
The following conditions must be met:
- in the heat exchanger, hot gases and liquid must move in countercurrent, otherwise the boiler may explode;
- do not confuse cold and hot pipes;
- the unit must be securely fixed;
- all dimensions of the chimney hood must correspond to the calculated data or exceed them;
- all technological distances around the unit must be maintained;
- specially prepared water is used as a heat carrier;
- for emergency gas shutoff, a valve is installed under the boiler.
Before starting the system, carefully inspect all components and parts.
If there is antifreeze in the heating part of the unit, drain it and rinse the entire system well with running water. Do not try to save on coarse water filters - they are installed at the lowest points of the entire system. Don't forget at the end heating season wash them from the mud mass.
Any person who is knowledgeable in such work will assemble the electrical part of the boiler. For work, a three-core cable with a plug is used, and a 220 V 32 A socket with grounding is mounted next to the boiler. Do not confuse the neutral and phase wires - the boiler will not work. To install the chimney, its pipe is attached to the boiler and taken out.
Figure 3. Connection diagram for a 2-circuit boiler.
Before the trial run of the unit, fill the heating network of the boiler with water, disconnecting it from the power supply. Open the valve at the bottom of the machine and close it when the system pressure reaches 0.9 bar. Filling the pipes with water must be done slowly to force air out of the system.
Check for tightness of all connections and the absence of leaks in the water supply and heating networks, make the first start of the unit. Insert the plug into the socket. The thermostat relay must be set to maximum. The boiler will start working when you set the operating mode switch to the extreme right position. This work must be done under the supervision of a gas company employee.
For example, we give the technology of installing a double-circuit gas boiler in a small private house and its heating scheme. Figure 2.
The general list of the main parts of the boilers is as follows:
- Ball Valves- they are installed on the mains of cold and hot water and on the heating part of the system;
- valves - used on the DHW drain. Basically, all of the above taps are used to shut off different parts of the system during preventive maintenance or repair;
- water purification filters - used when using metal pipes, and if a plastic conduit is used during installation, then the filter is attached to the water meter. To protect the boiler from mechanical particles, this part is placed on the heating return pipe;
- drives - used to connect individual parts of the system;
- magnetic and gas filters - the first protects the heat exchanger from scale formation, and the second cleans the gas flow from dust and mechanical impurities;
- pressure gauge and safety valves at a pressure of 3 bar;
- expansion tank for heating;
- special valve with bimetal sensor.
For use flexible corrugated hoses. The scheme of such a connection is shown in Figure 3.
After the furnace is in the room or they are attached to the wall with fasteners, all plugs that are installed on the nozzles are removed, and an angular strainer is mounted at the unit inlet.
Then ball valves are installed at its outlets and on all branch pipes. The next operation is the installation of DHW circuits and the heating system. Before the boiler must be installed a ball valve and a gas meter, a gas alarm and stop valve with bimetal sensor. After the work is completed, a gas company employee is called, and he connects your boiler to the system.
Boiler diagram
Of all the models that heating equipment is presented today, gas-fired installations are the most popular. The explanation for this fact is quite simple. Blue fuel is the cheapest and most accessible energy product, with the help of which autonomous systems operate. The advantages and principle of operation of a double-circuit gas boiler are well known to specialists. But this information will be very useful for an ordinary person.
How does a double-circuit wall-mounted boiler with an open combustion chamber differ from a floor model, where the chamber is closed? Where can dual-circuit heating systems be used? What is the device of the described installation? More about all this.
All models represented gas boilers, are divided into two large groups - single-circuit and double-circuit. The first houses one coil, which provides only heating in the house. In the second devices of coils, or circuits, two - one for heating, and the other for supplying hot water used for sanitary needs. How are the contours arranged inside the installation? To answer this question will allow a detailed description of the internal structure of the boiler.
The principle of operation of the installation
Each manufacturer has its own design of the internal filling of the described equipment. But they have one common design solution - two circuits are placed inside the case. The one responsible for heating works in a closed circuit. The water in it circulates in a circle, bypassing all the heating points installed in the premises of the house.
The coolant, which moves in a closed circuit, does not enter the second circuit. A separate valve is responsible for this. When a tap with water is opened in the faucets in the kitchen and bathroom, the valve blocks the access of the coolant to the heating system, which ensures that already hot water is supplied to the DHW circuit. When the faucets in the kitchen or bathroom are closed, the opposite action occurs.
Almost all gas boilers have the same technical knots, and models from different manufacturers differ only in some details. If we consider the assembly schemes, then inside the described device consists of three blocks. This is a heat exchanger, a burner and automation - a control system for the installation.
According to the principle of operation, boilers can be divided into convection and condensing
In the first, the fuel, burning, releases steam, which is discharged through the chimney to the outside. The second devices have a second combustion chamber. It collects exhaust steam, which is additionally heated and passes through a heat exchanger, which takes all the heat generated.
Both options have both pros and cons. For example, convection boilers have a simpler design, which means they are easier to manage. In addition, they are cheaper than condensing models. The steam is completely expelled outside, which means that condensation does not form inside - excess moisture is dangerous for metal parts. But here corrosion does not threaten them. The products of combustion are discharged to the outside by means of natural draft, so there is no need to use ventilation units.
The advantage of condensing boilers is that they allow the most efficient use of blue fuel. Due to the presence of a second chamber combustion efficiency they are one and a half times higher than those of convection boilers. There is only one drawback, but it must be taken into account. The steam inside the unit must constantly condense. This is possible only when a well-cooled coolant is supplied to the heating circuit. Therefore, it is necessary to use powerful radiators with high heat transfer. The best for this are aluminum and bimetallic batteries. But installing them is costly.
Note! On a system using the old cast iron radiators, the condensing boiler will not operate efficiently.
combustion chambers
Double-circuit wall-mounted gas boiler
Combustion chambers can also be of two types - open and closed. How do they differ from each other?
During the operation of an open combustion chamber, the air necessary for burning fuel is taken from the same room where the boiler is installed. Oxidation products are removed to the street through the chimney. Therefore, such installations can only be located in a separate and well-ventilated room. Otherwise, due to the lack of fresh air, the device will not work well. If there is not enough oxygen, carbon monoxide will begin to enter the room, which is very dangerous for human health and life.
Note! Installation of gas boilers with an open chamber is only allowed in a separate room. For the normal operation of the unit, a vertical chimney is required that can provide natural draft.
Closed cameras work differently. For them, a coaxial chimney is being constructed, where the combustion products enter with the help of forced draft provided by an electric fan. coaxial chimney is a design when one pipe is inside another larger diameter. Through the outside air is sucked in and supports the combustion process, and through the internal combustion products are brought out. You can install such a chimney in any direction - both horizontally and vertically.
Such a device has several advantages:
- Firstly, there is no need to allocate a separate room for it, so the gas boiler can be installed inside the house.
- Secondly, the efficiency of such installations is much higher.
There is only one drawback - without electricity, the electric fan will not work. And this means that the gas boiler will not heat up during a power outage either. This must be taken into account.
Burner design
Weisthaupt burner design
The design of the burner is responsible for the power of the unit. In gas boilers, it is installed in the chambers. It is here that fuel is burned and a large amount of heat is released. In this case, the oxidation products are expelled through the chimney with the help of draft.
Directly above the burner is a heat exchanger - a container where the coolant is located. When the combustion products rise up, rushing into the chimney, they heat the walls of the container, the water temperature rises, and the water enters the desired circuit through special pipes. The heat exchanger can be of two types. The most commonly used are plate and bithermic structures.
The plate heat exchanger consists of two copper pipes and plates treated with a special anti-corrosion compound. One pipe provides heating, and the second - hot water. The plates between them give off heat to the environment.
The bithermic heat exchanger has a different design. One pipe of a smaller diameter is placed in a pipe of a larger diameter. At least, the water supplied to the hot water supply flows, and water for heating passes inside the pipe of a larger diameter. Such a device, according to experts, is less reliable where the water quality leaves much to be desired. And all because gradually a precipitate forms on the walls of the pipes, which clogs the interaxal space. This causes the device to stop working effectively.
Floor and wall models
The principle of operation of the boiler largely depends on the version in which the device is presented. Modern manufacturers produce floor and wall gas boilers.
The choice of the wall option is justified only under certain circumstances:
- When there is a house or apartment, industrial or commercial premises, the area of which does not exceed 200 square meters. m.
- If satisfied with the total DHW performance equal to 14 liters per minute.
Wall mounted gas boiler ROSS AOGV
When the needs are higher, you will have to buy a floor double-circuit gas boiler. Both options come in two varieties. On sale you can find a wall-mounted double-circuit boiler with an open combustion chamber and a wall-mounted unit with a closed chamber. The same goes for floor options. Are there any differences in the operation of all these settings?
It has been noticed that a wall-mounted boiler with an open chamber is not purchased so often. Its main advantage is affordable price and lack of energy dependence. Where the light is often switched off, this factor is decisive.
Most often, consumers purchase a wall-mounted version with a closed combustion chamber. This is a new generation of heating equipment, which appeared on the market relatively recently. And such installations are produced using the latest technical developments.
The main advantage of this option is the presence of a complex electronic filling, which increases the safety of the boilers and simplifies their operation. But complex electronics, as practice has shown, does not function well in Russian realities. She is afraid of pressure surges that occur when gas is supplied, and the poor quality of water also affects her badly.
The compact size of the units is also more of a minus than a plus. Only thin-walled tubes of small diameter can fit inside them. Dirty water will clog them over time, and the unit will fail. For this reason, experts recommend choosing not a wall-mounted boiler, but a floor version.
In floor-standing boilers with an open combustion chamber, cast-iron heat exchangers are used. This increases the life of the device and the degree of reliability of its operation. For country houses most suitable floor standing boilers with closed chamber.
Other parameters affecting the principle of operation of double-circuit boilers
The principle of operation of double-circuit boilers from different manufacturers may differ slightly due to the use of additional elements.
One of them is a boiler. It can also be installed inside the case in its lowest part. The circuit responsible for the hot water supply passes through it. According to the principle of operation, such installations are slightly different from flow models.
Main technical characteristics
Hot water for technical needs is supplied from the boiler. But when it ends, the flow system turns on and works as described above. When the mixers are turned off, the water accumulates again in the boiler and is already heated there to the desired temperature.
The type of ignition of the installation is also of great importance. There are two options here:
- Piezo ignition.
- Electric ignition.
To start a boiler equipped with a piezo ignition, you must manually press the start button. The principle of the button is quite simple. The ignition wick is always lit in the unit, and the button opens the gas damper and provides fuel supply. There is only one advantage of choosing such a model - its independence from the presence or absence of light.
More cons:
- First, fuel is needed to keep the pilot wick burning, so it ends up being overused.
- Secondly, if the pressure in the gas supply system decreases, the wick will go out and the boiler will not work. You will have to ignite the installation manually, and this is not always convenient.
Electric ignition completely eliminates such shortcomings, but makes the boiler volatile.
Generalization on the topic
A detailed description of the principle of operation of double-circuit gas boilers allows you to understand what the advantages of their operation are. The purchase of such units helps to save money on additional water heating equipment - even if one circuit fails, the other continues to work.
Replacing a faulty circuit is much easier than repairing a similar independent heating installation. You can also use double-circuit models in the summer by turning off the system that heats the house. Therefore, using double-circuit gas boilers is more convenient and economical than analog units.
Among the various options for heating, natural gas invariably occupies one of the leading positions. In addition, the modern range of gas heating equipment is regularly updated with new modifications of various boilers and heaters. Among them, a worthy place is occupied by double-circuit boilers.
Their main advantages are compact structure, high performance and versatility of use. In addition to direct space heating, they also perform the function of heating water due to the presence of a flowing water heater. This is their main difference from single-circuit boilers.
The design of a double-circuit gas boiler
The structure of a double-circuit boiler includes a heat-insulated body with a heat exchanger located inside, a burner, one / two circulation pumps, an automation system and an expansion membrane tank. In order to ensure uninterrupted and safe operation of boilers, their models are equipped with special sensors, temperature controllers and control devices.
Burners come in 3 types:
- atmospheric type burner;
- forced draft burner;
- the burner is modulated.
In the first case, oxygen enters the combustion chamber in a natural way, in the second - through an electric fan. The latter is more preferable, because such a mechanism allows you to automatically adjust the power of the boiler, focusing on its immediate need for heat. This ensures higher efficiency and lower gas consumption, thus reducing overall heating costs. The same applies to modulating burners. In terms of their effectiveness, they take the 1st place. With their help, you can smoothly adjust the intensity and degree of heating of the coolant.
Now the heat exchanger. Its main criterion is the material. Cast iron heat exchangers are durable and have good thermal conductivity, but are sensitive to mechanical stress and are heavy. Such models are represented only by floor-standing boilers.
Most often you can find steel devices. They are durable and resistant to temperature extremes, but prone to corrosion. In order to improve performance, some manufacturers use composite steel heat exchangers and cover them with copper on the inside, and with an outer layer of a heat-resistant compound.
It should be added that there are 2 types of heat exchangers:
- double circuit plate heat exchanger
- bithermic heat exchanger.
In the plate apparatus, one circuit performs the function of heating. It is made of copper pipes and coated with a special composition in order to prevent corrosion. The second circuit is responsible for organizing hot water supply.
The bimetric heat exchanger has the form of a coaxial pipe, on which special copper “fins” are soldered. It provides heating of water in the combustion chamber itself. In this case, the inner pipe is intended for domestic hot water, and the outer pipe supplies the necessary medium for the coolant. Such heat exchangers replace a number of additional hydraulic units, which reduces the cost of the boilers themselves and increases the reliability of their operation.
An important structural component of 2-circuit boilers is an expansion membrane tank. This capacity is necessary for the removal of excess coolant into it during its heating.
Most models are equipped with circulation pumps. This is done in order to increase the power of the boiler and achieve the highest possible efficiency indicators. Pumps provide for operation from electricity, therefore, for the normal functioning of such boilers, a stable power supply is necessary.
The built-in automation system allows you to control and regulate the functioning of heating equipment. It includes:
- temperature sensors (they allow you to maintain the temperature at the required level);
- automatic system for turning on / off the boiler (provided for in case of a power outage);
- pressure sensors (they automatically turn off the boiler in the event of a gas supply failure);
- anti-freeze system (available for boilers that provide for periodic use and do not function during the cold season);
- automation pumping system(assumes periodic switching on of the pump in cases of prolonged downtime);
- self-diagnosis system (it allows you to detect problems in a timely manner), etc.
Depending on the model and manufacturer, double-circuit boilers can be supplemented with various modifications and automatic controls.
The principle of operation of a double-circuit gas boiler
The boilers in question provide for operation in 2 modes: heating and hot water. During heating, water is heated inside the heat exchanger. Depending on the required temperature, heating can vary from 35-80 ºС.
The heating mode is activated by a thermostat that reacts to changes in the ambient temperature. In the event of a decrease, it signals the start of the vacuum pump in return pipeline. Thus, the heated water is sent to heating system. At the same time, if the pressure exceeds 0.45 bar, the contacts close, which provokes automatic ignition of the burner, which is controlled by a microprocessor. In some boilers, the ignition is of the piezo type and is ignited manually.
After ignition, the boiler starts to work, gradually increasing power. Upon reaching the maximum value, the operation continues in the modulation mode. In situations where the power reaches high levels at the initial stage of operation, the automatic control system turns off the burner and turns it on again after 3 minutes.
Above the combustion chamber, in the lower part of which there is a burner, there is a heat exchanger. In the case when, in addition to heating, hot water is needed, the pump is turned on simultaneously with the burner, which provides forced circulation of water through the pipeline. Upon reaching the required parameters, the gas supply is reduced, and the boiler goes into standby mode. At the next temperature drop, the temperature sensor activates the fuel supply and ignition resumes.
In the summer, such boilers switch to single-circuit mode - only hot water. In this case, in order to prevent water from entering the heating circuit, it is blocked by a 3-way valve, and water begins to flow from the primary heat exchanger to the secondary. During the passage, the water heats up and enters the DHW system.
First, ignition is automatically carried out, after which gas is supplied. The power of the boiler gradually reaches the set maximum value and remains at the reached level until the water is heated to a certain temperature. Then the boiler switches to operation in the modulating mode. Since the heating circuit is turned off during summer operation, the generated heat is transferred to the inactive coolant, and then to the hot water supply system.
Connecting a gas double-circuit boiler
Double-circuit gas boilers are wall and floor. Their location is determined based on safety requirements and the possibility of connecting the equipment to the mains and water supply in the room. The boiler is installed at a distance of at least 20 cm from gas appliances. Also, do not place it near windows.
Since there are many models, and they all differ in their design and auxiliary elements, then each product is always accompanied by detailed instructions indicating the installation sequence. The only general aspect is mandatory installation taps on the heating pipeline (direct / return), water mains and heating drain.
When using metal pipes, a water purification filter is added to the connection diagram. Due to the content in aquatic environment impurities, the boiler may fail. The filter will avoid this trouble. Application plastic pipes provides for the installation of a filter in front of the water meter.
The connection of the heating main is carried out through the corresponding inputs / outputs of the boiler. A filter is also installed on the heating return pipe in order to prevent the ingress of foreign particles.
The scheme for connecting equipment to the gas main includes the installation of a thermal shut-off valve, a meter and a valve. All connection work must be carried out by specialists if they have permission to conduct such activities.
Since double-circuit boilers have a combustion chamber, the removal of residual products is carried out through a coaxial pipe, which is mounted on the outlet pipe and carried out to the street. The sequence of organization of such a chimney, as a rule, is indicated in the instructions for the boiler. There are turbine and chimney hoods.
As for electricity, it is recommended to connect the boiler to an outlet using a voltage stabilizer. As mentioned earlier, the water that acts as a coolant must be purified. In addition, too hard water can damage the hydraulics. To DHW circuit water was supplied under pressure, it is necessary to use auxiliary equipment, such as a hydraulic accumulator.
Since such boilers are very complex technical equipment, manufacturers provide a guarantee for it. Therefore, it is important that the installation is carried out by specialists. Incorrect installation can not only lead to a breakdown of the unit, but also create an emergency.
How to choose a gas double-circuit boiler
Double-circuit boilers are wall and floor. The former are characterized by compactness, performance and higher cost. The latter are easier to operate, bulky, but more affordable.
Today, fully automated wall-mounted gas boilers are more technologically advanced. They are controlled by a remote control and allow you to adjust the parameters of the heat exchangers based on immediate needs. Such boilers allow you to heat a room of 100-400 m². The only caveat is the high cost.
Standard recommendations for choosing a boiler include preference for models with a power reserve so that the equipment does not work at the limit of its capabilities. When deciding on a product, it is necessary to take into account a number of parameters such as:
- room area and ceiling height;
- the presence of windows;
- the degree of insulation of the room, etc.
The standard calculation of the boiler power is 1 kW per 10 m² with a ceiling height of at least 3 m. If the room is poorly insulated, then the boiler is selected with a large power reserve.
As practice shows, floor boilers last longer than wall-mounted ones and are much easier to operate. In most models, all settings are made manually. Such units are cheaper and non-volatile. Their power is enough to heat a room of 80-300m². However, for such models, it is necessary to additionally purchase a pump, an expansion tank and an emergency assembly. Installation of such a boiler is more expensive than a wall-mounted one. Thus, in the end it turns out that the total cost of a floor-standing boiler, together with installation, will hardly be less than a wall-mounted one, whose installation is much easier.
Floor-standing double-circuit boilers, due to their non-volatility, are optimally suited for residents of an area where power outages periodically occur, and for those who already have a complete heating system and only need to replace the old one. heater. In this case, the purchase of such a boiler is beneficial.
Conditions for the safe operation of a gas double-circuit boiler
The key to a long and reliable service of the boiler is a competent installation. Modern models heating equipment are equipped with a special automation system that will allow you to maintain set parameters and also includes an emergency shutdown.
The standard rules for safe operation include the following items:
- it is forbidden to use the boiler to persons who are not familiar with the rules of operation;
- it is impossible to independently eliminate the problems that have arisen in gas equipment;
- the unit must not be allowed to operate on a gas that does not meet the established requirements without reconfiguring / replacing the nozzles;
- it is forbidden to independently change the design of the boiler and its elements;
- do not leave the unit in working condition for a long time without attention;
- it is forbidden to place flammable aggressive substances near the boiler;
- appropriate filters must be installed on the gas pipeline and water supply;
- ventilation and flow grilles must always be open;
- the volume of water in the boiler must correspond to the established displacement, etc.
If you follow the basic rules, no problems should arise. It is worth noting that this heating equipment, in addition to its efficiency, is also distinguished by a high degree of reliability. So with proper operation and timely diagnosis of potential problems, such a boiler will last from 10 years or more.
Double-circuit boilers are the most popular on the market today. This is due to many factors. The most important of these is that a device with two circuits performs several functions. Let's take a closer look at what a double-circuit gas boiler is. The principle of operation of the device, as well as the connection diagram and the operating instructions, will also be touched upon. This article is suitable for those who want to understand this issue in more detail.
Some general information
A double-circuit gas boiler, the principle of operation of which we will now consider, can cope with two tasks at once: firstly, it is heating and maintaining the set water temperature for the heating system, and secondly, heating the carrier for use for household purposes. Thus, your home is not only warm, but also has hot water. This is the essential difference between a double-circuit boiler and any other. We can make a simple conclusion that the design has two high-performance heat exchangers, each of which performs its own function. In addition, a double-circuit gas boiler can be of different capacities. Today on the market there are models from 12 to 35 kW. This is quite enough to heat a large room of 350-400 square meters. The performance of most models ranges from 8-12 liters per minute.
About the advantages of double-circuit boilers
It is safe to say that these units have much more advantages than disadvantages. Now we will consider all the advantages. Firstly, this is a significant gas savings. This was achieved through the use of modern heat exchangers. By the way, it made it possible to make the operation of the units completely silent, so a double-circuit gas boiler can be installed in any convenient place. Dimensions in most cases allow installation without any problems. If the floor option is not suitable, then it is always possible to install the device on the wall, which is especially true for small apartments, where everyone square meter important. The operation of the double-circuit boiler is completely autonomous, which is facilitated by the appropriate equipment (pump, ECU and security system).
A little about the cons
Nothing lasts forever, nor is it perfect. The double-circuit boiler has several disadvantages. First, it should be noted, a noticeable loss of water at the initial stage. Let's look at a specific example. So you turned on hot water, an additional coolant automatically started working. To go, you need to wait about 30-40 seconds, depending on the brand of the boiler. Everything that comes off the tap before this time is called a loss. We can say with great confidence that this is not such a big drawback. If you need to heat the carrier for household purposes, then the double-circuit gas boiler does this in flow mode without the possibility of accumulation. Let's go ahead and talk about how the unit works.
Double-circuit gas boiler: principle of operation
As noted above, the device can operate in several modes. If a single-circuit boiler is intended only for space heating, then a 2-circuit boiler can also heat water, but this has already been said. If you need to heat the room, then the principle of operation is as follows: the carrier, in our case it is water, enters the heat exchanger, which heats it up to a certain temperature. Today the range is around 35-85 degrees Celsius. The thermostat starts the heating mode automatically. This is done when the temperature in the system drops below normal. As a result, work starts circulation pump and supplies water from the heat exchanger (preheated) to the system. The pressure in the system is also taken into account, which should not fall below 0.5-0.7 bar. If necessary, the microprocessor sends a signal to the burner, which heats the media to the desired temperature.
The principle of operation of the boiler: part 2
But it doesn't end there. After switching on, the boiler starts to work on the rise. First at minimum power, and eventually reaches its maximum. When a double-circuit gas wall-mounted boiler heats up the media to a predetermined temperature at some stage, the unit goes into modulation mode. If at the first start-up the power exceeds the allowable one, the microprocessor sends a signal to turn off the burner. Reactivation is carried out after three minutes. The combustion chamber is metal and has a special heat-resistant winding. Above it is a heat exchanger, below it is a burner. The latter lights up exactly at the moment when the temperature of the carrier in the system drops and the water needs to be heated. Together with it, the circulation pump is also included in the work, designed to drive water through a closed system. When the set temperature is reached, the gas wall-mounted double-circuit boiler goes into standby mode. In some models, the burner burns, but at a minimum, in others it goes out and lights up when gas is supplied.
A little more about the features of the work
To prevent the carrier from entering the second circuit, a three-way valve is used. Thus, it was possible to achieve the supply of heated water from the boiler to the system through one line (supply) and return through the other (return). It is worth paying attention to the fact that the double-circuit gas wall-mounted boiler is designed in such a way that the carrier moves in a circle without forming a plaque. But this applies to the first heat exchanger. In the second, water is taken from the pipeline. As practice shows, the quality of the media often leaves much to be desired. For this simple reason, it makes sense to install filters in front of the carrier that will remove insoluble compounds. If the circuit breaks, the boiler can operate in room heating mode. So you won't sit in winter time in a cold apartment or house.
How the DHW system (hot water supply) works
If you switch the wall-mounted double-circuit gas heating boilers to summer mode, then only the carrier heating system for domestic needs will function. In fact, the batteries will be cold, and hot water will come from the tap. The principle of operation here is extremely simple. changes its position and closes the heating line, thereby opening the way to the secondary heat exchanger, where the carrier is sent. When water passes through the carrier, it heats up and goes straight to the hot water circuit. The process begins with the start of the relay, the contacts of which are closed when the media consumption is more than 2.5 liters. From the microprocessor, a command is given to ignite the burner, and then the gas valve gradually opens. Power increases incrementally. Then the device switches to the mode of smooth temperature control. It is worth noting that wall-mounted double-circuit gas heating boilers from all manufacturers are designed so that the burner turns off when the set temperature is exceeded by 5 degrees, and turns on when the carrier temperature drops by 1 degree.
Gas double-circuit turbocharged boiler: advantages and disadvantages
The essence of the work of turbocharged models is that there is an air supply for the gas combustion process, as well as the removal of combustion products is carried out using a built-in fan. In this case, there is a pair of air ducts of small diameter. The process takes place simultaneously. The products of combustion are released into environment, and the oxygen necessary to maintain combustion, on the contrary, is supplied to the boiler. The fans are mounted inside the boiler. But it is worth paying your attention that forced withdrawal is suitable for units with a power of not more than 30 kW. As for the advantages, they are obvious, there is no need to build a chimney. Two pipes are brought out into the street, one of a large diameter, the second of a small one. The first is used to supply oxygen, the second - to remove combustion products. But there are also disadvantages here, the fact is that double-circuit gas heating boilers have a more complex design, and it is far from always possible to make a hole in the wall. Let's look at another important point.
User manual
It is difficult to give specific recommendations here, this is due to the fact that each manufacturer has its own recommendations. But there are several general rules that must be carried out for the normal operation of your boiler. Firstly, there is a special filter between the pipeline and the heat exchanger. So, periodically it needs to be cleaned or changed. How often to do this, find out in your passport. Another requirement is to monitor the pressure in the system. In most cases, it should not fall below 0.5-0.75 bar. If the indicator is lower, it is necessary to add water to the system, if it is higher, then vice versa, drain a certain amount of carrier. Often there are two valves, as well as a pressure gauge showing the pressure. If the arrow is in the green zone, then everything is fine. There is one trick, which is to reduce the amount of scale in the system. It consists in not raising the temperature of the carrier above 45 degrees Celsius. With an increase, there is a breakdown of salts and other elements that form a dense plaque.
Scheme of a double-circuit boiler
Let's talk about how to properly connect the device. Often this is done by professionals, but if you decide to do it yourself, then nothing will come of it without certain knowledge. Firstly, a double-circuit gas boiler, the principle of operation of which we have already considered, must include a mechanical filter at the inlet. It is advisable to first install a shut-off valve on the boiler return. This is done so that it is not necessary to air the system when the unit breaks down. After the boiler is mounted directly, communications are further connected, that is, water supply, gas, and also installed to remove combustion products and supply oxygen. In any case, the start-up of the system is carried out under the control of the gas service. Do not forget that the gas double-circuit floor or wall-mounted boiler must be installed strictly according to the level.
Conclusion
If you are going to install the device yourself, then you will definitely need a double-circuit gas boiler diagram. Often it makes sense to pay and entrust this matter to professionals. This is due to the fact that you will be dealing with explosive gas, so any leak can lead to serious consequences. That, in principle, is all on this topic. Now you know how a double-circuit gas boiler works. The instruction manual is mandatory reading, because you are dealing with serious equipment. Moreover, if you do not read the relevant documentation, you may not know many important points and “fail” the warranty on the device, as a result of which, in the event of a breakdown, you will have to spend your own money.