The boiler's own heat exchanger capacity is often not enough to meet the needs of domestic hot water. To make up for the shortage, a boiler is used indirect heating.

When the water in the tank cools down, based on a signal from the thermostat, the valve switches to supply. After warming up to the setting temperature, it returns to its place, the flow is blocked, and then the water goes to the devices.

The connection diagram for a single-circuit boiler with an indirect heating boiler with a three-way valve is similar. When designing the system, you need to take into account: the temperature in the boiler heat exchanger must be higher than the set temperature in the boiler. Otherwise, the boiler will continue to heat up even when the boiler is turned off.

Connection double-circuit boiler to the indirect heating boiler through two circulation pumps: each circuit has its own pump. With this system, water heating for DHW and heating is carried out simultaneously, and they can be turned off separately. The operation of both pumps is controlled by a thermostat. To prevent the flows from mixing, a check valve is installed behind each pump.

The scheme of a single-circuit boiler with an indirect heating boiler with a distribution hydraulic arrow (with a hydraulic manifold) is used if there is more than one heating circuit, incl. when they are different (radiators and heated floors). The same option is suitable for installing double-circuit units together with boilers.

Connection diagram for a double-circuit gas boiler and boiler.

1) Boiler heating (loading) pump.
2) Temperature sensor - thermostat.

Connection features

How to connect an indirect heating boiler to a single-circuit boiler:

1. Find a place for the tank as close to the boiler as possible.
2. Connect the input (top) and output (bottom) in series.
3. Connect the pump. The axis must be located in a horizontal plane; deviation from the horizontal will lead to rapid wear of the bearing.

The pump is equipped with filters. During operation, they should be periodically checked and cleaned.

Connection diagram for a single-circuit gas boiler and an indirect heating boiler.

How to connect an indirect heating boiler to a double-circuit boiler, diagram with a three-way valve: the valve is installed at the outlet of the boiler, from which the circuit branches. One branch goes to the heating circuit, the second to the boiler. The boiler has a single return; the pump can also be common.

In this case, the priority is supply to the boiler. When the coolant in it reaches the set temperature, the thermostat sends a signal to the three-way unit to switch. From this moment on, hot water is supplied only to the heating circuit.

Video about connecting a boiler to a gas boiler.

Hot water supply, without which comfortable living in modern housing is impossible, can be established by connecting an indirect heating boiler. Such units are much more profitable and efficient in operation than traditional flow-through heaters due to their higher power and efficiency. We will consider what options for connecting the boiler are used later in the article.

The installation of modern water heaters guarantees the supply of hot water in the proper volume at several distribution points - in the bathroom, kitchen, etc. Specifications the selected boiler must meet the water consumption requirements at comfortable temperature in the required volume. To ensure rapid heating in a short time, it is necessary to correctly calculate the power of the water heater. For example, when consuming water in volumes of 500 liters per hour, a tank with a capacity of 100 liters or more is required.

An indirect heating boiler is similar to a regular storage boiler

Main elements of the heating system:

• Heating boiler;
• A pump that ensures constant circulation of water;
• Three-way valve;
• Hose with connections for connection to the pipeline system;
• Indirect heating boiler.

The indirect heating unit looks like a simple one storage boiler, powered by electricity, and performs the same tasks of creating a hot water supply. The main difference is the operating principle used using a heating boiler for heating.

The basic kit of the indirect heating device includes:

• storage tank in a casing, surrounded by a layer of thermal insulation;
• coil built-in for water circulation;
• Sleeve for connecting a temperature sensor;
• Pipe for connecting the boiler to the water supply system;
• Recirculation line (on some models).

The coolant is passed through the coil of the storage tank

The operating principle of the device is based on heating the coolant passed through the coil of the storage tank. When interacting with water, heat is transferred from the coil with a simultaneous increase in both temperature and pressure in the tank. During operation, it is necessary to monitor the degree of heating using the setting function desired temperature, avoiding limit values. When connecting an indirect heating boiler, the use of temperature sensors will help with this. When the water heats up, the temperature sensor signals the pump or three-way valve that the required temperature has been reached, and the water in the coil stops circulating. A similar principle underlies the operation of the sensor when the coolant cools.

When connecting, several can be used various schemes piping with a single principle of supplying cold and releasing heated coolant: cold water enters from below into a container for indirect heating, and when heated, it is released to the water supply. As heated water passes through the coil, it gives off heat and comes out from below. This connection option allows you to maximize the volume of heated water.

The heating scheme can be described as follows: when the hot flow is directed to the user, the cold water supplied from below acts as a piston, and, passing through the heated coolant, the cold flow heats up and moves into top part reservoir.

The piping of an indirect heating boiler is carried out according to the principle of piping a radiator, differing only in the need to stop the circulation of water in the coil after reaching the desired temperature. To solve this issue, a three-way valve or an additional pump connected to the built-in thermostat is used. It is possible to use a dead-end DHW or circulation circuit. The first option will require additional opening of the tap to drain the cooled water in the pipes.

Connection diagram for an indirect heating boiler to a gas boiler (single-circuit, double-circuit)

Hot water supply, without which comfortable living in modern housing is impossible, can be established by connecting an indirect heating boiler.

Indirect heating boiler - connection diagram, operating principle

Organize a constant uninterrupted supply of hot water in a private home tap water it is possible using an indirect heating boiler (storage heater), which uses the energy of a heating boiler: electric, gas, solid fuel, etc.

Why do you need a storage heater?

A KN boiler is not the only way to organize hot water supply. You can install a double-circuit gas boiler, instantaneous electric water heater, electric storage heater, but...

Each of the listed methods introduces its own functional limitations to the operation of the hot water supply system:

• Flow-through heating devices cannot provide sufficient performance to supply multiple hot water intake points.
• They don't provide consistency. temperature regime water. An electric storage heater may “object”, but with its sufficient capabilities, it “eats” quite a lot of electricity for your money.

These two factors impose restrictions on the mode of using hot water in a house if there are several water intake points, for example, in one house they decided to wash the dishes and take a bath or shower. But there may not be enough water... Hot!

Purpose and operating principle of an indirect heating boiler

Connecting an indirect heating boiler to the system allows you to avoid limiting the number of hot water consumers.

Correctly calculated heat exchanger power and its volume allow you to quickly and evenly heat the water in it to the desired temperature, which is the same throughout its entire volume.

For example, a 100 liter tank can provide about 500 liters of hot water per hour. An ordinary electric “apparatus” is not capable of this.

The operating principle of an indirect heating boiler necessarily involves a “tandem” with a heat source in the house heating circuit.

The volume of the heater tank is consistent with the power of the heating boiler, which ensures an increase in water temperature by transferring coolant heat from one circuit (heating) to another (DHW circuit).

There can be several heat transfer “radiators” in a boiler.

For example, a solid fuel boiler can be used to heat water, solar collector, Heat pump geothermal system heating. Each of these “heat sources” has autonomous coolant flow lines connected by “heat transfer” in the heated medium.

Indirect heating boiler device

Boiler is storage capacity, mainly cylindrical, thermally insulated from environment, with a heat exchanger installed inside.

The role of the hot circuit heat exchanger is played by the coil complex shape. Water from the boiler heating circuit circulates through it, heating the entire volume of water in the tank through the circuit wall.

A massive magnesium anode is installed in the tank, which protects the device elements from galvanic corrosion.

How to choose an indirect heating boiler?

The main parameter of such a device is its usable volume. The numerical value of this parameter is influenced by many factors:

• number of house residents consuming hot water;
• residents' habits;
• their mode of life, etc.

Based on “such parameters” it is difficult to determine the exact value of the volume. Therefore, when calculating the volume, take approximately 80 liters per resident. The range of volumes for devices of this type is quite wide: from 200 to 1500 liters. However, choosing a heater with a significant reserve volume is unprofitable, since energy costs will increase. And the device itself “increases in price” as its volume increases.

The second important parameter is the coolant flow through the heating circuit (data from the device data sheet). As a percentage, it should not be more than 40% of the total flow through the heating boiler.

You should also pay attention to the material from which the container is made and the quality of its manufacture. Heaters with a stainless steel tank have the greatest longevity and price. An important point It may be possible to dismantle the internal heat exchanger to clean it.

Thermal insulation should be polyurethane foam or mineral wool.

The name of the heater manufacturer and the “geography” of its production, along with the listed factors, play a significant role in determining the price.

The choice is yours! The modern heating engineering market is saturated with offers of a wide range of parameters.

Connection diagram of the boiler to the heating system

Piping an indirect heating boiler involves connecting it to the water supply system and heating circuits. When connecting it to the water supply:

• cold water is supplied to the bottom of the tank;
• hot outlet at the top of the tank;
• the recirculation point is located in the middle of the tank

When connecting the heating circuit, the movement of the coolant should be directed from top to bottom: the hot coolant is supplied to the upper pipe, the cooled coolant comes out of the lower one. In this way, the maximum efficiency of the boiler is achieved, since the hot water at the inlet warmed up the already hot layers of water in the upper part of the tank, and then, giving off heat to lower-temperature layers, exited the heating circuit back into the boiler.

To correctly connect an indirect heating boiler with your own hands, you need to understand the basic diagrams of its connection

Connection via three-way valve

This connection option assumes the presence of two circuits in the heating circuit:

• heating circuit (main);
• storage heating circuit (DHW system).

The distribution of coolant flow between them is assigned to a three-way valve. The storage tank heating line has higher priority than the heating line.

The three-way valve is controlled by signals from the boiler thermostat. When cooling drinking water in the DHW system, the thermostat switches to the lower permissible value, controlling a valve that directs the entire coolant flow from the boiler circuit to the storage heating circuit.

When the required water temperature is reached, the valve “on command” of the thermostat switches to its original position, directing the flow of coolant through the heating radiators. IN summer time, when the heating system is turned off, the boiler simply “goes off” (turns off).

This scheme is the most common. It is used in case of high consumption of hot water, and as an alternative to a double-circuit gas boiler when working with very hard water. The secondary heat exchanger of the boiler quickly fails when working with hard water.

When setting the thermostat response temperature, it is necessary to take into account the heating temperature of the coolant in the boiler. And the temperature set on the boiler should always be less than in the boiler. Otherwise, the boiler, having turned off the heating circuit, will try to endlessly heat the water in the boiler.

Two-pump scheme

In this scheme, the coolant flows are controlled by the active influence of circulation pumps in various lines.

In this scheme, the DHW line also has priority - it is connected before the circulation pump of the heating system. It would be more correct to say that the heating line of the water heater and the heating line are connected in parallel, and each has its own circulation pump. Switching the operating mode of the pumps is carried out by signals from the same boiler temperature sensor.

To eliminate the mutual influence of coolant flows, a check valve is installed after each pump.

This scheme, like the first, provides for turning off the heating line when the DHW circuit is turned on, which should not lead to significant cooling of the house in a short time of heating the water in the storage heater (initially it heats up in about 1 hour).

But in complex heating systems, two boilers can be used, one of which constantly operates for heating, while the second operates according to a second mode switching scheme.

Scheme using hydraulic arrow

In multi-circuit heating systems, to balance the coolant flows in different parts of the circuit with their circulation pumps, a hydraulic distributor is often used: a hydraulic needle or a hydraulic manifold.

This connection diagram for an indirect heating boiler uses several heating lines: radiator, heated floor, boiler heating circuit, etc. It can function without a hydraulic module combined with manifolds, but then it is necessary to provide for the installation of balancing valves to compensate for pressure drops in various “branches” of the system.

When designing such systems, it is imperative to use the experience of professional practitioners.

Using a recirculation system in a DHW circuit

The presence of a third input in the boiler tank allows you to connect a water recirculation line to it. The purpose of this system is to provide almost instantaneous supply hot tray into the area of ​​its consumption when the tap is opened. That is, there is no need to drain cold water from the main into the sewer, waiting for hot water to “arrive” from the heater.

This possibility is realized through the creation of a looped highway constantly flowing water with its own circulation pump - recirculation system. It can be implemented with or without a heated towel rail.

The piping of an indirect heating boiler, the diagram of which is given above, includes some additional components. Let's consider the purpose of some typical elements in the piping of a heating device.

Check valve– eliminates the reverse movement of water in the pipeline.

A valve is installed at the inlet to the boiler to prevent hot water from flowing back into the cold water supply system if the device overheats. Exceeding the water pressure in it and the pressure in the water supply can push hot water into the “cold” water supply.

An automatic air vent (before the second check valve) prevents the pump from “airing” when it starts.

Safety valve – protects the heating storage device from excess pressure.

Expansion tank - provides pressure compensation in the DHW circuit when the taps are closed.

Attention! Permissible pressure in expansion tank should be less than the “stall” pressure of the safety valve.

Advantages and disadvantages

Let's summarize positive traits devices-

Indirect heating storage water heater:

• does not significantly affect the load on the home’s electrical network during cold seasons;
• has sufficiently high productivity with the correct calculation of all necessary parameters;
• does not allow the inner surface of the heating circuit to come into contact with running “aggressive” water with a high salt content;
• isolates the heating circuit coolant from running sanitary water;
• the use of a recirculation line makes it possible to use hot water immediately after opening the tap at the point of consumption;
• with multi-circuit heaters involves the use of several heat sources.

Now a little about the disadvantages:

• “convenient” technologies in heating and hot water supply must be paid well;
• a long period of initial heating of the water in it (from 1 hour or more);
• The significant “dimensions” of the equipment require the provision of a separate room for the boiler room.

Indirect heating boiler - connection diagram, piping, principle of operation

Indirect heating boiler - connection diagram, how to make the piping. Operating principle, device. How to choose and connect with your own hands

Connecting an indirect heating boiler

Home Articles Connecting an indirect heating boiler

Indirect heating boiler is a device designed to provide hot water supply. It is installed so that, if necessary, hot water can be turned on simultaneously in several points of the house. If you put hot water directly from the boiler into the pipes, without a boiler, then the power of the heat generator is simply not enough to fully warm up the consumed volumes of water. In most cases, containers from 80 to 120 liters are installed. The liquid in them is constantly heated and creates a sufficient supply to guarantee a continuous supply of large volumes of hot water.

Operating principle of the boiler

Cold water is supplied to the tank from below, and from above it, already heated, goes into the hot water pipeline that goes to the shower, to the taps in the kitchen or to other places. A built-in sealed spiral heat exchanger, also called a coil, is responsible for heating the water. The coolant coming from the boiler circulates through it. The water in the coil does not flow inside the tank, but moves only inside a closed pipeline to the boiler and back.

Heat from the water in the coil to the water in the boiler is transferred through the metal body of the heat exchanger. Some manufacturers make the coil from copper, but Thermico boilers use longer-lasting, high-efficiency stainless steel. Its thermal conductivity indicators guarantee the fastest heat exchange between the water coming from the heat generator and the water that moves directly throughout the entire volume of the tank.

Optimal connection diagram

Exist various ways connecting an indirect heating boiler to gas, solid fuel or electric boilers. All of them are, to one degree or another, demanding on the qualifications of specialists performing installation work. Next, we will consider the simplest, but at the same time reliable and efficient scheme, in which there is no manifold or hydraulic needle. Installing these two elements poses a number of challenges and creates a more complex hydraulic system.

The presented circuit uses two circulation pumps. One will work for the heating system, and the second will supply hot water. The pump in the heating circuit is turned on all the time the boiler is running. The circulation pump going to the boiler is turned on by a signal from the thermostat, which should be installed in the tank. The thermostat detects a drop in water temperature in the boiler and reports this to the pump. The pump begins to pump hot coolant through the heat exchange circuit between the boiler and the tank, thereby heating the water in the boiler to the required temperature.

This scheme can be used with equal efficiency for both electric and gas or solid fuel heat generators. Undoubtedly, best choice For heating a private house, a solid fuel boiler is now used long burning. High quality heat generator solid fuel can significantly reduce the heating budget during the season compared to a gas boiler. It is important to choose a good manufacturer and not overpay.

On this moment leaders in terms of price-quality ratio in the niche solid fuel heat generators are mine and pyrolysis boilers Termico. The design of Thermico boilers, thanks to a number of improvements, shows higher efficiency. Devices from this manufacturer are capable of operating on wood with a humidity level of up to 40%.

There is a modification of the circuit where the heating circuit pump is turned off by the same thermostat that turns on the boiler circuit pump. In this case, the boiler heats up faster, but then the heating stops completely and with prolonged inactivity, the temperature in the batteries can drop significantly. After the tank has warmed up, the heating pump starts and the cold coolant from the radiators rushes into the boiler heat exchanger, which leads to the formation of condensation. And in the case of cast iron heat exchanger may cause its destruction. Therefore, it is better not to stop heating, even if this will extend the heating time of the boiler.

With a significant length of pipeline with radiators, the coolant also has time to cool noticeably, and low temperature water in the boiler return will harm it. To protect the heat generator from condensation and prevent thermal shock when cold water gets into it, the system provides protective circuit with three-way valve. The diagram shows a temperature of 55°C. This means that the built-in thermostat will automatically select the required flow intensity to heat the return. At the same time, the channel will not be wide enough for the entire coolant to move only along this small circuit. Most of the water will go to radiators.

Connecting a boiler to a double-circuit boiler

Installation of a boiler on a double-circuit boiler is carried out on a heating circuit. As the name suggests, double-circuit boilers have two circuits - one for heating and the second for hot water supply. So the hot water supply circuit is designed to be supplied directly to the consumer. If you connect a boiler heat exchanger to it, the boiler will not work efficiently. Therefore, if it is necessary to place the tank in the heating system, it is installed in the heating hydraulic circuit.

The hot water circuit is limited to a maximum temperature of 60°C for safety reasons. The heating circuit has a coolant heating limit of 80 °C. It will be more efficient to heat the tank with a hotter circuit, as a result of which installing a boiler on a hot water supply circuit loses all meaning. If you have a double-circuit boiler and need to install a heating tank, then you just need to turn off the second circuit and stop using it. Installation is carried out in the same way as connecting to a single-circuit boiler, described in the previous section.

Recirculation device

Recirculation is provided by an additional circuit in the hot water supply system, which departs from the boiler supply pipeline and returns not to the tank return, but to a special recirculation inlet. A separate pump is installed on the recirculation circle, which accelerates the movement of the coolant. As a result, the speed of movement of hot water in the interval from the boiler to the recirculation branch increases. And this, in turn, leads to more intense heating of this feed section.

Recirculation is used only for large heating circuits, where the coolant has time to cool down noticeably before reaching consumers. Therefore, not all boilers are equipped with a special inlet for organizing such an additional circuit. Its connection diagram is quite simple and contains only a supply tee and an additional recirculation pump. If necessary, you can install a thermostat on it that regulates the flow rate and a check valve to protect against unexpected changes in the direction of water movement.

Double-circuit boiler

Under double-circuit boiler This means an indirect heating boiler with two heat exchangers. The first, as in a single-circuit boiler, is connected to the boiler and heats the tank with the temperature obtained from burning fuel in the heat generator. And the second coil can be connected to additional source heat, for example, to a water heating system that is powered by solar or other energy. Collaboration two heat exchange circuits increases the rate of water heating in the hot water supply system.

In addition, when elements powered by conditionally free solar or wind energy are included in the scheme, significant cost savings are achieved. This is especially noticeable when living in a private house big family and daily hot water costs are high. The above diagram is an example of a working heating system that combines the energy of fuel combustion in the boiler and converted into thermal energy sun.

Connect the boiler to a private house it is necessary according to a scheme that takes into account individual needs specific system heating. In the vast majority of cases optimal device the heating system will be as shown in the first diagram given in the article. It is completely safe, reliable and practical. If necessary, additional elements can be included in it, but it is better to coordinate amendments to the presented diagram with specialists.

How to properly connect an indirect heating boiler?

How to connect an indirect heating boiler to a solid fuel boiler? Typical connection and wiring diagrams for indirect equipment.

Connection diagram of BKN to CO and DHW

For BKN to work correctly, you need working diagram connecting an indirect heating boiler. In this case, the heating will function and hot water will be in the house at required quantities at all parsing points.

The piping of the indirect heating boiler itself does not cause any particular difficulties; the same materials and fittings are used as for any work on hot water, both with the boiler and with the hot tap water supply system.

The principle of operation of the BKN and the parameters for its selection, calculations by volume and models, see the following review in the section “Boilers for boilers”.

Here we will dwell in more detail on the question of how to connect an indirect heating boiler in pairs to a heating boiler, consider possible options and comment on the diagram.

Location of BKN in the house

The closer the BKN is to the boiler, the more efficient the heat removal and heat transfer from CO to DHW occurs. Typically, the installation of an indirect heating boiler is carried out in the boiler room, although I have seen several options for installing BKN in corridors, bathrooms and other utility rooms.

In this case, of course, the heat removal efficiency will be inferior to the option when the connection diagram for the indirect heating boiler is implemented in the boiler room, directly next to the boiler.

However, this option also has its advantage - hot water consumers become closer to the BKN, which means heat loss through the hot water supply is noticeably reduced, and the waiting time for hot water in systems without circulation is reduced.

How to install BKN in a boiler room

In total, in nature there are 4 types of location of BKN in the boiler room. These are wall-mounted horizontal and vertical boilers, and floor-mounted BKN, installed horizontally and vertically. The former have fittings for mounting on the wall, the latter do not have such fittings, but have stands for installation on the floor in the boiler room.

Wall-mounted BKNs are usually small in volume - from 30 to 200 liters, floor-mounted - from 200 to 1500 liters. Trying to hang a floor-standing boiler on the wall can end in disaster. Imagine that you have hung an 800-liter floor-standing BKN on a wall made of aerated concrete. These 900 kilograms of water and steel will eventually knock down your wall. And after one they will pour boiling water over the entire first floor.

Therefore, the installation of an indirect heating boiler must occur exactly as its manufacturer intended. Wall-mounted - hung on the wall, floor-mounted - placed on the floor.

Installing an indirect heating boiler on a wall is no different from mounting the most ordinary electric water heater - the same anchors, the same procedure.

The only moment! When you install an indirect heating boiler, make sure that the inlet and outlet pipes for supplying and exiting coolant to the CO “look” towards the boiler.

Otherwise, you will have to suffer a lot, you will pile up a whole system of tubes, corners and contours, the piping of the indirect heating boiler will be “crooked”.

And if everything is done correctly, then you will have only 2 direct outlets from the CO system. Beauty!

The correct installation diagram for an indirect heating boiler is given below.

Installation diagram of an indirect heating boiler - WALL OPTION:

Installation diagram of an indirect heating boiler - FLOOR OPTION:

Connecting an indirect heating boiler to CO and DHW

After the BKN has established itself in its rightful place in the boiler room or bathroom, next step The indirect heating boiler is being connected to the heating system.

This is quite simple to do, because any normal man with the bare minimum of tools can connect an indirect heating boiler to the CO and to the DHW.

There are only four pipes in the BKN itself - the inlet and outlet of the hot coolant of the heating system, and the inlet and outlet of hot water of the DHW system. In the case where circulation is organized in the DHW system, the last two pipes will be the inlet of the circulating warm water from the DHW system and the output of heated water back to the DHW system with circulation.

While the taps at the distribution points are not open, the water circulates through the hot water system and is heated by the boiler to the required temperature. As soon as the tap at the dispensing point is opened, water flows “on demand” to the consumer.

To connect an indirect heating boiler, you need to connect the first two pipes to the heating system from the boiler, and the second two pipes to the hot water supply system.

When the combined boiler is operating, the water in the BKN will be heated not only from the coolant in the heating system, but can also be heated to the values ​​​​set by the consumer using an electric heating element built into the BKN.

Below is a diagram for connecting an indirect heating boiler when the BKN is located directly in the boiler room.

Indirect heating boiler piping - WALL MOUNTING DIAGRAM:

Piping an indirect heating boiler - DIAGRAM FOR FLOOR INSTALLATION:

In the case of a DHW system in which hot water circulation is implemented, a circulation pump is added to the circuit, which is located in front of the DHW inlet pipe in front of the BKN.

In the end, all DHW diagram and CO with BKN connection will look like this:

The indirect heating boiler must be connected in such a way that it is possible to exclude the device from the general circuit for prevention or repair. For this purpose, a bypass is provided at all inputs/outputs - CO and DHW.

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One of the leading manufacturers heating equipment in Russia - the company "Evan", began its history in 1997. It was then.

Connection diagram for indirect heating boiler, piping, installation

Connection diagram for an indirect heating boiler, how the piping is done, how the installation takes place, correct installation - see the options for wall and floor mounting on our website.

It is no longer possible to imagine a modern home without a hot water supply system. Water heaters using gas or electricity are also designed to provide comfort to your home.

The indirect heating boiler guarantees an uninterrupted supply of hot water thanks to its connection to the heating boiler. The device has such a simple design that you can easily make it yourself, and its operating principle allows you to integrate the device into any type of heating system. However, during the installation process, do not forget that performance and thermal power indirect heating storage water heater directly depend on how correctly the connection diagram is chosen.

Installing an indirect heating boiler will create autonomous system hot water supply in the house

The operating principle of an indirect heating boiler is based on heat transfer. The design of this type of water heater consists of two circuits. One of them is connected to the heating boiler, and the second to the water supply. Heating of the liquid occurs due to the constant circulation of hot working fluid inside the heat exchanger circuit. To increase energy efficiency and process control, boilers are equipped with sensors and switching units, which gives them the ability to work with high-tech heating units.

Advantages of a water heater:

• independence from gas and electricity supplies. Since the boiler is connected to a heating boiler, it does not use any additional types of energy;
• has high efficiency at low cost;
• the design and principle of operation eliminate contact of water with the coolant, which increases safety;
• allows you to set up an inexpensive recycling system.

Like other household appliances, the use of a storage water heater also has negative aspects:

• the need for additional capital investments during installation;
• relatively high cost of factory-made devices;
• long time to enter the nominal operating mode.

When choosing a boiler, pay attention to both its volume and the power of the heat exchanger. An important factor is the size and shape of the device, since storage water heaters are large in size.

Kinds

A wide variety of indirect heating boilers allows you to choose a device optimal design and the required installation method

Depending on the volume, indirect heating water heaters are divided into:

• floor A large tank forces you to install the device on additional supporting elements provided by the equipment manufacturer;
• wall-mounted Small devices have mounting brackets for installation. The only requirement in this case is proximity to the heating boiler.

To ensure the operation of the boiler during the warm season, some models are additionally equipped with heating elements, which allows the device to function as a conventional storage-type electric water heater.

Connection diagrams

Before you begin to study the diagrams for connecting water heaters to the heating system, you need to familiarize yourself with the principles of the correct functioning of the device:

• cold water is necessarily supplied from below, while the heated liquid is taken through the upper pipe;
• the coolant from the heating system must flow to the top of the device and go into the heating circuit, passing down the heat exchanger;
• The recirculation point is located in the central part of the tank.

By following these principles, you can achieve maximum efficiency and increase the efficiency of your water heater. Connecting an indirect heating boiler to single-circuit heating boilers possible in several ways.

With three way valve

Connection diagram for an indirect heating boiler with a three-way valve

With increased hot water consumption, a storage water heater connection diagram with the installation of a three-way valve is used. Of course, in this case, installation is complicated by the need to install a separate heating circuit to connect the heat exchanger, but this method allows you to achieve maximum performance.

The inclusion of a three-way valve between the boiler and heating system circuits allows you to distribute the coolant flow according to the signal from the thermostat sensor installed in the tank. It works like this: when the water temperature is below a threshold value, the valve opens, a flow of hot liquid from the boiler enters the heat exchanger of the device. After heating the water in the boiler, the valve redirects the working fluid to the main heating branch. In this case, the hot water supply system has priority.

For proper operation circuits with a three-way valve require precise adjustment of the thermostat, since if its upper temperature exceeds maximum temperature coolant, the valve will be open constantly.

Hydraulic (with two pumps)

The hydraulic boiler connection diagram is especially effective in complex heating systems and involves the use of two or more circulation pumps

The hydraulic connection method is an improvement on the three-way valve circuit. It is notable for the use of two circulation pumps and check valves. This method involves the installation of two parallel circuits, in each of which the movement of the coolant is provided by a separate pump.

The circulation unit of the water heater branch is mounted before the insertion point of the heating system pump, which is due to the higher priority of the boiler circuit.

The pumps are controlled according to an already known algorithm (provided by the temperature sensor of the water heater). The hydraulic connection diagram is very convenient in bulky systems that include two heating units. In this case, the additional boiler periodically switches to work with an indirect heating boiler, directing the coolant into its circuit when the water temperature in the tank drops. Check valves installed after the pumps in the direction of flow of the coolant are designed to prevent mixing of working fluid flows.

The design of modern heating boilers provides for the connection of external thermostats to control the operation of their circulation pumps.

Connection features

The connection diagram with a hydraulic arrow allows you to balance the coolant pressure in heating systems with a large number of circuits

In systems with two or three heating units and a large number of radiator and underfloor heating Several circulation pumps are used. IN complex schemes it is necessary to balance the flow of working fluid, which is achieved by installing a hydraulic distributor, which includes a hydraulic needle with a manifold, or balancing valves on each circuit.

You can do without balancing devices, but in this case it will be impossible to achieve uniform distribution of the coolant, which will negatively affect the durability of the equipment.

Often a heated towel rail is connected to the recirculation circuit

A huge advantage of indirect heating boilers compared to electric water heaters is the possibility of recirculating hot water. That is, the heated liquid constantly moves along a separate circuit connecting the device and water collection points. This eliminates the need to drain cold water every time you turn on the tap.

To connect a separate branch, the boiler is equipped with an additional pipe. The only drawback of the recirculation system is the mandatory presence of a separate circulation pump.

Combined operation of a water heater with double-circuit and solid fuel boilers

Connecting the boiler to a solid fuel boiler increases the safety of its use

Installing an indirect heating water heater in a heating system with a double-circuit boiler makes it possible to choose low or high priority for the hot water supply system.

In the first case, the boiler is installed in series with the heating circuit along traditional scheme. If the device has priority over the heating system, then it is mounted parallel to the main circuit, using a thermostatic head for adjustment.

The operation of solid fuel units is often associated with the risk of overheating during critical temperature increases. This is often due to objective features, less often due to incorrect settings of thermostatic radiator valves. In this case, the indirect heating boiler acts as a buffer energy accumulator, taking excess heat from the heating circuit. The only condition is the natural circulation of the coolant, which will make it possible to avoid overheating of the boiler even during a power outage, when the operation of the circulation pump becomes impossible.

Installation instructions

Most indirect heating water heaters are designed to be connected to a water supply with an operating pressure of no higher than 6 bar. Otherwise, installation of a reduction device is required. Besides, hanging structure Provides for attachment to a solid base. It is best if it is a capital bearing wall building. Otherwise, the installation of the boiler is carried out according to the following algorithm:

• shut off the water supply at the entrance to the house or apartment;
• the device is fixed in a suitable place;
• install check and three-way valves or a circulation pump;
• connect the supply and return lines of the coolant supply circuit;
• install a water heater safety group and shut-off valves at the inlet and outlet of the device;
• make connections into hot and cold water supply pipelines;
• supply water and test the system.

When connecting the boiler Special attention attention should be paid to sealing the connections. It is better to use tow and special paste.

Water heater safety group - required element his harness

Installation secrets, or how to avoid mistakes

1. Correct installation of an indirect heating boiler involves not only installing the device in accordance with the manufacturer’s recommendations, but also setting it up. Otherwise, a situation may arise in which the boiler will not switch to work with the heating system. Therefore, it is important to comply with the requirement that the boiler setting temperature will exceed the thermostat setting values.
2. During installation, it is important not to confuse the direction of supply of coolant to the boiler. Failure to comply with this requirement is fraught with a decrease in unit performance and an increase in energy costs. Incorrect connection of the circulation pump will result in increased noise and reduced service life. You can find out how to select and correctly install this unit.
3. When connecting a boiler, do not skimp on installation shut-off valves. Installed at the inlet and outlet of water and coolant Ball Valves will make it possible to dismantle the device without draining liquid from the heating system and without cutting off the cold water supply to the apartment.
4. Some novice installers do not install a check valve on the supply line, considering this part unnecessary. This is not recommended, since the heated water can easily flow back into the water supply.
5. Make sure that the shut-off valve from the hot water supply riser is closed during operation of the boiler. Otherwise, the water will simply go into the general system.
6. After installing the water heater, it is necessary to check the operation safety valve. Remember that your safety depends on the serviceability of this part. That is why it is strictly prohibited to install a check valve instead of a safety device.
7. To prevent electrical damage, the device must be grounded. In the case of using a combined indirect heating boiler, a protective shutdown device must also be installed. In addition, it is better to connect to the electrical network using a separate line using additional package switches.

How to properly connect an indirect heating boiler (video)

Installing an indirect heating boiler will allow you to get required amount hot water with minimal energy consumption. In this case, it is important to correctly connect the water heating equipment so that the installation of the boiler does not interfere with the normal operation of the heating system.

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To heat water in an indirect heating boiler, you can use a gas or solid fuel boiler, solar water heater or heat pump. In this case it is possible to work instantaneous water heater of this type, both in conjunction with a single-circuit and double-circuit heating unit. WITH indirect heating boiler connection diagram varies depending on the type of boiler and the selected hot water supply method.

Piping the water heater requires connecting it to the heating system, as well as cold and hot water supply lines. In this case, cold water enters from below, hot water is discharged from the top of the tank, and the recirculation point is located approximately in the middle of the boiler.

The heated coolant should move in the opposite direction - from top to bottom.

The coolant from the boiler enters the upper pipe of the water heater, and returns to the heating main from the lower pipe of the boiler.

In this way, the efficiency of the device is increased by transferring heat first to the hottest layers of water.

For correct connection boiler, you need to know the basic methods of connecting it.

Connecting a wall-mounted boiler to heating unit

Connecting the boiler to a gas boiler

To connect an indirect heating boiler to a gas heating boiler, its design provides temperature sensor installed in the tank.

Connection to a double-circuit boiler

To operate the boiler in tandem with a heating unit that has a hot water supply circuit, a three-way valve is used. With its help, the flow of heated coolant is distributed between the main heating circuit and the additional hot water supply circuit.

The three-way valve is controlled by signals received from the thermostat installed in the water heater. When the water in the boiler cools below the set value, the thermostat turns on the valve, which directs the flow of coolant from the heating pipeline into the hot water supply circuit. The thermostat switches the valve to its original state when the water temperature in the tank reaches above the set value. In this case, the coolant flow is directed into the heating main. In the warm season, the flow is not redirected, but the combustion mode of the boiler is controlled. When the water temperature in the boiler decreases, the thermostat, through a three-way valve, “ignites” the main burner of the unit, and when it increases, the gas supply to the burner stops.

Connecting the boiler to the boiler using a three-way valve

This connection diagram is perfect for gas boilers equipped with a circulation pump and automation. In this case, the valve can be controlled by the boiler itself based on a command received from the water heater thermostat.

In a connection diagram with a three-way valve, the water heater circuit has priority over the heating circuit. The use of this method of connecting a boiler is justified for large-volume tanks or with high water hardness, which will not allow the DHW circuit to operate normally.

When setting the maximum water temperature in the boiler (thermostat response temperature), you should keep in mind that it should be less than the temperature set for the boiler automation.

Connection to a single-circuit heating unit

When connecting a water heater to a single-circuit boiler, a circuit with two circulation pumps is used. This type of connection can actually replace a circuit with a three-way sensor. A special feature of this connection is the separation of coolant flows according to different pipelines using pumps. The hot water supply circuit also has higher priority over the heating circuit, but this is achieved only by adjusting the switching algorithm. Therefore, it is more correct to talk about parallel operation of both circuits.

Alternating switching centrifugal pumps also carried out according to signals from a thermostat installed in the tank.

To prevent mixing of coolant flows, a check valve must be installed in front of each pump.

Installation diagram of a boiler in a system with two circulation pumps

The operation of this scheme is similar to the previous case, with the only difference being that the thermostat controls the alternating operation of two pumps. When the DHW pump is turned on, the heating pump is turned off, therefore, the heating system begins to cool down. However, the short time of heating the water in the boiler does not lead to a noticeable decrease in the temperature inside the house and can only be felt during the initial start-up.

Sometimes several heating units are used to heat large houses. In this case, an additional pump is installed to ensure the operation of the water heater.

Scheme using a hydraulic collector

The use of a hydraulic collector in heating systems with multiple circuits

In complex multi-circuit heating systems, there are several circulation pumps responsible for ensuring the operation of individual circuits. In order to balance the coolant flows from different pumps, a hydraulic distributor or manifold is used. This device allows you to compensate for pressure differences in various circuits and branches of the heating system. Without a hydrocollector, balancing valves would have to be used, which significantly complicates the setup and operation of the heating system and the arrangement of hot water supply.

When using an indirect heating boiler in such a system, additionally consult with specialist practitioners.

By connecting a storage water heater to a solid fuel boiler, two goals are achieved at once - hot water supply is connected and a system for emergency coolant discharge is obtained. The point is that in systems with solid fuel boilers Often, in order to increase comfort, thermostatic valves are installed on radiators. However, in this case the boiler may overheat. The same threat is real in case of unstable power supply for systems with forced circulation coolant.

If you install a high-capacity boiler, this process is not dangerous, since the excess heat is used to heat the water in the water heater tank. Of course, for the operation of such a system, it is necessary to install a boiler with natural circulation.

Connection diagram for an indirect heating boiler to a solid fuel boiler

Solid fuel boiler safety group.

1. Expansion tank.
2. Boiler safety group.
3. Hot water supply pipeline.
4. Shut-off valve on the supply line.
5. Heating system pump.
6. Water heater pump.
7. Check Valve.
8. Shut-off valve.
9. Drain tap.
10. Solid fuel boiler.
11. Boiler shut-off valve.

To close the natural circulation branch when the pump is running, a check valve is installed at the outlet pipe of the water heater. When the pump is turned off, the valve opens, allowing heat to be discharged into the boiler.

The check valve is important element systems

A boiler that has a recirculation line input allows for instant supply of hot water. At the same time, by opening the tap there is no need to drain cold water from the “hot” pipeline.

This is possible thanks to the use of a separate loop circuit with its own circulation pump. Such a circuit is called a recirculation system. An additional heated towel rail can be installed in this line.

Diagram of a boiler included in the recirculation system

The following is used in the piping of a boiler included in the recirculation system:

• Check valve - to prevent mixing of hot and cold water flow.
• Air vent – ​​to prevent air from entering the system when the pump is turned on.
• Safety valve – serves for emergency pressure relief.
• Expansion tank - compensates for thermal expansion of the coolant when the taps are closed.

The pressure in the expansion tank must not exceed the response pressure of the safety valve.

Mistakes made during installation

When installing or operating the boiler, it is necessary to avoid typical mistakes:

• Installation of the boiler at a considerable distance from the boiler. It is necessary not only to install the water heater as close as possible to the heating unit, but also to correctly orient its pipes relative to the pipelines to facilitate installation.
• Incorrect connection of the coolant inlet and pressure pipeline. The coolant is always supplied to the upper part of the boiler, and cold water is always supplied to the lower pipe.
• Incorrect installation of the circulation pump. The pump should be oriented according to the manufacturer's instructions.

Installation carried out in accordance with all the rules will not only provide reliable hot water supply at any time of the year, but will also give the boiler the opportunity to operate in a more gentle, economical mode.

Video. Connecting an indirect heating boiler to a gas boiler

The indirect heating boiler has long been known as one of the best ways provide a private house or cottage sufficient quantity hot water. These devices are also used quite successfully in apartments, offices, factories, etc. The principle of operation of the boiler is so simple that it is not so difficult to make it yourself. However, the efficiency of this device largely depends on how correctly the piping scheme for the indirect heating boiler is chosen.

Basic principles for connecting a boiler

Water is supplied to the device through two circuits. The first is a heating circuit, which is usually connected to the home heating system. The second circuit is designed for heated water, which comes from the water supply system and is then discharged to the bathroom, kitchen, etc.

When figuring out how to install, the first thing to remember is the following principles:

1. Cold water should be supplied to the bottom of the boiler, and hot water should be discharged at the top of the device.
2. must flow into the tank from top to bottom, i.e. water or antifreeze is supplied to the upper pipe of the boiler and returned to the system from the bottom.
3. The recirculation point will be located in the center of the boiler tank.

Compliance with these principles will maximize the efficiency of the device, since the temperature of the water in the upper part of the boiler will remain quite high, and then the coolant will heat the colder water in the lower part of the tank.

Strapping options for different situations

Most often, when connecting an indirect heating boiler, three main schemes are used:

• option with three-way valve
• use of two circulation pumps
• use of a hydraulic boom.

In addition, it is worth considering the use of a recirculation system, which can significantly improve the quality of hot water in a private house or apartment.

How to use a three way valve?

When consumed large quantity hot water is most often used by connecting an indirect heating boiler using three way valve. In this case, it is necessary to create two heating circuits: the main one, which heats the room, and a separate circuit required to heat the water in the boiler. To distribute the coolant flow between these circuits, a three-way valve is used, which is controlled by the boiler thermostat.

A three-way valve in the indirect heating boiler piping circuit is used to regulate the direction of coolant flow. The valve is controlled by a boiler temperature sensor

This system works as follows. When the water temperature in the tank drops below the set value, the valve directs the coolant to the boiler heating circuit. After the water has heated to the required level, the valve returns the coolant flow to the main heating circuit. Wherein main role It is the heating of the water in the boiler tank that plays a role, not the heating circuit.

Note! In areas with very hard water, it is recommended to use an indirect heating boiler with a three-way valve instead of a double-circuit boiler, the elements of which fail too quickly under such operating conditions.

For this type of system to work correctly, it is very important to set the thermostat correctly. The fact is that if the maximum value of the heating temperature of the water in the tank is higher than the heating temperature of the coolant in the boiler, the water in the boiler will be constantly heated. Switching to the heating circuit will not occur, since the maximum temperature in the boiler will not be reached.

Two pump system

Instead of a three-way valve, a system with two recirculation pumps and a check valve can be used. In this case, the installation of an indirect heating boiler also includes two parallel circuits: a heating circuit and a boiler circuit. A separate circulation pump is used to control each circuit.

In the indirect heating boiler piping scheme using two circulation pumps, the heating circuit and the boiler circuit are mounted in parallel, but the main role is played by the boiler circuit

Since the hot water supply line has priority, the boiler circuit is installed in front of the heating system pump. To control the pumps, the same boiler temperature sensor is used, obeying the signals of which the pumps turn on and off. The two-pump scheme can be very convenient when using a heating system that includes two boilers. In this case, one boiler is completely used for heating the room, and the second is connected to both the heating system and the boiler.

When the water in the boiler cools, the coolant flow is directed to heat it, and at the end of the process it returns again to heating system. A check valve is necessary so that the coolant flows do not mix.

There is no need to fear that the quality of heating of residential premises will suffer due to the use of a contour heating boiler. The water in the DHW system heats up very quickly, usually in less than an hour. During this short time, the rooms simply do not have time to cool down.

How does a hydraulic boom work?

In modern private houses and even in ordinary apartments The heating system can be quite complex. In addition to the radiator line, it often includes a boiler heating circuit, a heated floor system, and other elements.

A hydraulic arrow in the circulation pump piping circuit is necessary to regulate coolant flows and compensate for pressure differences in separate parts complex heating system

Each such circuit is equipped with a separate circulation pump. In this case, the flows in various circuit circuits must be balanced. To manage such multi-circuit systems heating systems use a hydraulic distributor, which may include a hydraulic needle and a manifold. Pressure drops in individual circuits can also be neutralized using special balancing valves.

How more complex system heating system, the more carefully you should install it. It is best to entrust the design of connecting an indirect heating boiler using a hydraulic arrow to an experienced specialist, since it is quite difficult to adjust such a system “by eye”.

A few words about the benefits of recycling

To avoid having to wait until the cold water in the hot water tap is replaced by heated water, use a recirculation system. When using it, a looped highway is created along which the ox constantly moves and at the same time is constantly heated, i.e., does not have time to cool down. Thus, the consumer receives hot water almost instantly as soon as the corresponding tap is opened.

To create a constant cycle, you will need another circulation pump. A very convenient addition to such a system is a heated towel rail.