Combination boiler connection diagram. Connecting an indirect heating boiler to a single-circuit boiler - diagrams, options, step-by-step instructions

Hot water supply, without which comfortable living in modern housing is impossible, can be established by connecting a boiler indirect heating. Such units are much more profitable and efficient to operate 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.

Installation of modern water heaters guarantees the supply hot water in the proper volume at several points of disassembly - in the bathroom, kitchen, etc. Specifications the selected boiler must meet the requirements for water consumption at a 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 storage boiler powered by electricity and performs the same tasks of creating 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 function of setting the 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 different piping schemes can be used with a single principle for supplying cold and discharging heated coolant: cold water enters from below into a container for indirect heating, and heated water is discharged 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 in the form of a piston, and, passing through the heated coolant, the cold flow heats up and moves to the upper part of the tank.

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, use a three-way valve or additional pump connected to the built-in thermostat. 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

You can organize a constant uninterrupted supply of hot sanitary water in a private house 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

A boiler is a storage tank, mostly cylindrical in shape, thermally insulated from the environment, with a heat exchanger installed inside.

The role of the hot circuit heat exchanger is played by a coil of 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:

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

Based on “such parameters” it is difficult to determine exact value 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 pricing.

The choice is yours! Modern market heating engineering is full of proposals for 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. This is how it is achieved maximum efficiency boiler, 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, left 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 within short time heating water in a storage heater (initially heats up in about 1 hour).

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

Diagram using a hydraulic boom

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 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.

Non-return valve – prevents 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 (in front of 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 DHW circuit with the taps closed.

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

Pros and cons

Let's summarize positive qualities 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 contact inner surface heating circuit 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 volumes of water consumed. In most cases, containers from 80 to 120 liters are installed. The liquid in them is constantly heated and creates a sufficient supply to ensure 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 metal case heat exchanger. Some manufacturers make the coil from copper, but Thermico boilers use a more durable, highly efficient 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

There are various ways to connect 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. 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 long-burning solid fuel boiler is now used. High quality heat generator solid fuel can significantly reduce the heating budget during the season compared to a gas boiler. It's important to choose good manufacturer and at the same time not overpay.

At the moment, the leaders in terms of price and quality ratio in the niche of solid fuel heat generators are Termico shaft and pyrolysis boilers. 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 warming up the tank 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 a cast iron heat exchanger, it can cause its destruction. Therefore, it is better not to stop heating, even if this will extend the heating time of the boiler.

If the pipeline with radiators is long enough, the coolant also has time to noticeably cool down, and the low water temperature at the boiler return will harm it. To protect the heat generator from condensation and prevent thermal shock when it gets into cold water, 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 intensity 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 an additional heat source, for example, to a water heating system that is powered by solar or other energy. The joint operation of two heat exchange circuits increases the rate of heating of water 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 a large family lives in a private house and the daily costs of hot water are at high level. The above diagram is an example of a working heating system, which combines the energy of fuel combustion in the boiler and converted into thermal energy from the sun.

You need to connect a boiler to a private house according to a scheme that takes into account the individual needs of a particular heating system. In the vast majority of cases, the optimal design of the heating system will be as shown in the first diagram given in the article. It is completely safe, reliable and practical. If necessary, it can be included additional elements, 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

In order for the BKN to work correctly, you need a working diagram for 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 one 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, the next step is connecting the indirect heating boiler 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 the device can be excluded from general scheme for prevention or repair. For this purpose, a bypass is provided at all inputs/outputs - CO and DHW.

Indirect heating boiler design

Electric storage water heaters are gradually becoming more common sources of hot water, using a regular household electrical network for power. They are equipped with conventional heating elements responsible for heating water in the internal tanks. Electricity costs are not the highest, but not the lowest either - the larger the boiler, the higher the consumption. But in the world of water heaters, there is also a more economical technique.

Indirect heating boilers use heat extracted from heating systems to heat hot water. To do this, they are equipped with metal coils. Having a large area, they quickly heat the water to the temperature set on the panel. The temperature regime is supported by built-in or connected automation.

Scheme of organizing the DHW circuit using spacious wall and floor boilers indirect heating has the following advantages:

Saving on electricity – in winter time it will be tangible;
Fast preparation of hot water - “indirect” ones are characterized by high productivity;
High reliability - many experts tend to use this particular scheme rather than double-circuit boilers.

The scheme is really simple and reliable, all that remains is to select and connect the indirect heating boiler to the heating system. Let's see how to make the connection.

Basic connection diagrams

In our review we will look at several of the most popular schemes for connecting indirect heating boilers to heating equipment. They differ in their degree of complexity, so you have to choose the best option.

Connection without regulation

This scheme is characterized by maximum simplicity, but is practically not used in hot water supply systems. Yes, we can safely connect an indirect heating boiler to a gas boiler without additional wiring. But you will have to somehow put up with the lack of ability to adjust the temperature to your liking. In fact, the temperature of the water in the tank with this connection scheme depends on the temperature of the coolant at the connection point.

Remember that the maximum water temperature in the tank of an indirectly heated boiler (water heater) is only a couple of degrees lower than the temperature in the heating circuit.

In some cases, the coolant (water) in heating systems warms up to high temperatures, up to +70-80 degrees. More impressive indicators are also recorded. Such powerful heating leads to the fact that the temperature of the water in water heaters jumps to similar levels. We open the tap, and our hands are scalded with almost boiling water. Agree that such a connection is not safe, even if you dilute the water with a mixer.

Thus, the connection diagram for an indirect heating boiler must necessarily contain regulatory elements. Temperature stability at the outlet will allow you to avoid problems with scalding your hands and other parts of the body. Moreover, most connection methods are relatively simple.

Connection with circulation pump

Connecting an indirect heating boiler to a single-circuit boiler using a low-noise “wet” type circulation pump is one of the simplest schemes. It uses the following nodes:

Circulation pump – provides forced submission coolant into the inside of the water heater (into the tank);
Thermostat for an indirect heating boiler - built-in or external;
Check valve - prevents the reverse flow of coolant and stops circulation when the pump is turned off.

Let's take the simplest case, when the water heater already has automation. To carry out the installation, we will need an indirect heating boiler piping, which includes the following elements - a tap for quick disconnection from the heating network, a circulation pump, a check valve, a tap for shutting off the water supply, a check valve for the water supply.

We begin connection work - we install our indirect heating boiler in a given location (floor or wall mounting). Next, we lead the pipe to the heating system and connect through the tap. We install a circulation pump at the outlet of the water heater, and after it we install a check valve.

A gas boiler with an indirect heating boiler is a simple and reliable combination for organizing a durable and productive hot water circuit. To connect the water heater, we can use one simple diagram using a three-way valve. It will play here approximately the same role as in a conventional double-circuit boiler - there it switches the movement of coolant from the heating circuit to secondary heat exchanger, in which the water is heated (when the tap is opened).

It works in a similar way here. To organize the connection, we will need a three-way valve, a low-power circulation pump and the indirect heating boiler itself. The circulation pump is common here; it circulates the coolant through heating circuit and for the water heater. This process is controlled by a three-way valve connected to the thermostat. As soon as the temperature in the tank drops below normal, the valve switches and water heating in the DHW circuit begins.

There is no need to think that when the water is heated, the temperature in the house will begin to drop - the water heats up quickly, and your household will never have time to cool down. After all, it does not cool down when the DHW circuit is operating in double-circuit boilers.

The hydraulic arrow allows you to connect to the boiler with optimal distribution of the coolant. Radiators, underfloor heating systems, as well as indirect heating boilers are connected to its outlets. Each direction contains its own circulation pump. Another pump is installed between the hydraulic needle and the pump.

The connection is made through distribution manifolds in a similar way. As in the case of a hydraulic arrow, each direction has its own circulation pump. The advantage of this connection method is the uniformity of temperature in the outputs in each direction. The indirect heating boiler is connected to the hot collector, and the cooled coolant leaves it into the cold collector. A check valve is installed at the boiler outlet, and a circulation pump is located at the inlet.

The connection diagram for an indirect heating boiler with recirculation offers the following convenience - you open the tap, and hot water immediately begins to flow from it. Usually everything happens exactly the opposite, since the section of pipe from the water heater to the tap itself could have time to cool down. The result of this is this: when the tap is opened, cold water flows from it, heating up only after a few seconds. The longer the pipe, the longer the heating takes.

Recirculating hot water through an indirect heating boiler avoids this unpleasant phenomenon. When connecting, it is necessary to implement the following scheme - take the pipe from the tap back to the boiler. A circulation pump is also installed in the hot water supply system. Thanks to this, the pipe all the way to the tap contains hot water. A drawing of this connection method will provide more detailed information.

To operate the system, you will need to purchase an indirect heating boiler with recirculation support.

How to choose the right connection

An indirect heating boiler can even be connected to a double-circuit boiler, if this makes sense - for example, such a scheme will allow you to connect multiple water points and use them simultaneously. Here we select any available scheme. In the absence of heated floors and several heating circuits, the optimal solution would be to connect through a circulation pump or a three-way valve.

If you need to create a connection diagram for a solid fuel boiler that runs on wood, we recommend choosing the option shown in the picture below. Here the priority of the indirect heating boiler is used. The coolant for heating devices is taken from its outlet. This connection reduces the thermal load on the radiators and ensures a reliable supply of hot water.

Connection through hydraulic arrows and manifolds is used if it is necessary to provide heat and hot water building of impressive size. For example, it could be a two- or three-story cottage. In this case, a powerful boiler is installed in the system, and distribution equipment is connected to it.

Electrical connection

During the warm season, the equipment is turned off, so you need to somehow solve the problem with hot water. To do this, we can shut off the heating circuit and leave only the indirect heating boiler running. But the most common practice is to simply connect the water heater to the electrical network - for this purpose, heating elements are installed here (in some models they are built-in initially). It is necessary to connect to the electrical network through circuit breakers.

Video

To provide a home required quantity hot water is used additional device– indirect heating boiler (IBC). Its use can be considered one of the most rational and economically justified.

We will try to find out which piping scheme for an indirect heating boiler is most effective and how to connect the equipment to avoid common mistakes.

Before purchasing and connecting a buffer tank-accumulator (as BKN is also called), you should understand design features the most popular types. The fact is that there are many types of equipment, including combined models that operate from heating systems and alternative energy sources simultaneously.

We will look at traditional coil boilers that use hot water as a heater.

Design features and operating principle

What does indirect heating mean? Directly heated devices operate by connecting to electricity or a gas burner; BKN has a different heat source. The water is heated by connecting to the hot water supply, that is, it turns out that the source is the coolant - hot water (or its substitute).

Externally, the BKN resembles a standard water heater - that is, it has a barrel-shaped shape, although modern models more ergonomic. For ease of use and installation, they are given a rectangular configuration

If we consider new models of famous brands, we will notice that gas boilers and often have the same design. They are mounted side by side or one under the other - this way you can save on the placement area.

The main element that performs the heating function is a steel or brass heat exchanger (coil) with a large surface area, which is located inside a metal tank coated with a protective layer of enamel. To prevent the water from cooling too quickly, use outside the body is surrounded by a layer of thermal insulation, and some models are surrounded by a casing.

Schemes and rules for connecting BKN

The connection diagram and installation features of an indirect heating boiler depend on the class of the device and. It is necessary to choose the right installation location, focusing on the location of the boiler, pump insertion and existing wiring. Let's try to figure out what needs to be taken into account when installing heating equipment.

Option #1 – piping with a three-way valve

This is one of the most popular schemes, since when it is used, parallel connection heating system and BKN, equipped with shut-off valves. The boiler must be installed near the boiler, a circulation pump must be installed in the supply, then a three-way valve.

This scheme is successfully used if several heating devices are used, for example, two different boilers.

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, an indirect heating boiler is used.

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.

Connecting a double-circuit boiler to an 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:

Find a place for the tank as close to the boiler as possible.
Connect the input (top) and output (bottom) in series.
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, priority is given to the boiler. When the coolant in it reaches the set temperature, the thermostat sends a signal to the three-pass valve to switch. From this moment on, hot water is supplied only to the heating circuit.

Video about connecting a boiler to a gas boiler.

To install a hot water supply system (DHW), there is several options, some of them are double-circuit and single-circuit boilers with a separate boiler.

If in a dual-circuit device a small heat exchanger is already built in that heats water for domestic hot water, but in a single-circuit system with a boiler, the task of heating water for domestic needs is assigned to it.

Double-circuit boilers are usually equipped relatively small capacity for hot water supply, therefore they cannot provide the required temperature for many consumers for a long time.

Types of gas boilers with indirect heating boilers

Eat two options water heaters for DHW:

indirect heating (IH);
direct heating.

The BKN is connected to the installed gas boiler. Inside it there is a heat exchanger (this can be a pipe twisted in a spiral or a “tank-in-tank” design).

Hot water from the heating system circulates through this heat exchanger, heating the water in the boiler. The latter is connected to the cold water supply network (CWS), and from the collapsible pipe the hot water supply is supplied to consumers.

Direct heating boiler can be compared with a conventional gas boiler heating. It also has gas burner and a water tank. The burner heats the water in the tank regardless of the system central heating.

Important! When installing a BKN, it is necessary to estimate the power that will be spent on DHW. If there are many consumers and use water frequently, The boiler power may not be enough for heating, and the temperature in the rooms will be lower than the set one.

In this case, it is advisable to replace the boiler with a more powerful one, or use a different type of water heater.

Schemes for connecting a boiler to a single-circuit boiler

Exists three ways connecting the boiler to the boiler.

Direct connection of the water heater to the heating system

In this embodiment, the BKN is included in the heating system, in series or in parallel with other radiators. The simplest and most ineffective scheme is not recommended for use and is given for reference.

Photo 1. Scheme of direct connection of a water-heating gas single-circuit boiler to the heating system.

If the boiler temperature is set below 60 °C, this scheme becomes even less economical, and the water takes a very long time to heat up.

Temperature increase

Added to the connection diagram three way valve- a special device that switches the movement of coolant when the temperature in the water heater tank drops to DHW and vice versa.

Thus, if the DHW water cools down, The heating is temporarily switched off.

All boiler power is redirected to DHW.

The temperature on the device in this scheme is set higher ( usually 80-90 °C).

And the heating temperature is regulated by a three-way valve.

Reference! The boiler temperature must be set at 5 °C higher than the required water in the domestic hot water supply.

Using a thermostat in a water heater and automation

If a thermostat is installed in the BKN (a device that gives a signal when the set temperature is reached), and the boiler controller has contacts for connection boiler thermostat, then this circuit is the most preferable.

In this case, the boiler electronics know about the temperature of the water in the DHW system, and it decides itself where to direct its power: for heating water in the BKN or for heating.

Photo 2. Thermostat for a water heater in a heating system, with it you can find out data on the water temperature.

Materials and tools

Materials:

Pipes, shut-off valves, check valves - not applied to them special requirements: use the same materials as for working with hot water supply or heating systems.
Expansion tank- per system domestic water supply a separate one is required, serves to prevent sudden pressure changes when opening/closing taps.

Attention! The tank must be intended for use with hot water; such devices are usually designated special markings.

Circulation pump— as a rule, a separate pump is installed in the heat exchange circuit with the water heater.

In addition, in DHW systems with recirculation, a separate pump is required to circulate water in the DHW circuit.

This will eliminate the need to wait for hot water to arrive through long pipes from the installation site of the water heater: the water will be hot immediately.

Wires and small electrical wiring— if you plan to connect the water heater thermostat to the boiler automation.
Fasteners- especially in the case wall installation, also for securing pipes and pumps.
Standard plumbing set of sealants, seals, gaskets.

Tool:

gas key;
wrenches of various diameters;
adjustable wrench;
building level;
hammer drill, screwdrivers, screwdriver;
minimum set electrics: knife, wire cutters, electrical tape, phase tester.

Installation process: how to connect

Ideally, the boiler should be located as far as possible closer to the heating boiler to minimize heat loss.

Cold water is always supplied to the bottom pipe of the boiler, and hot water is drawn from the top.

Select a location for the water heater so that it does not interfere and is easy to maintain. Mount brackets, stands, and secure it to them.
Connect to the HVS network: make a challenge, put stopcock and a coarse filter.
Through a tee, take the cold water line to consumers, connect the second output to the boiler via safety valve.
Connect the domestic hot water line to the boiler, not forgetting about the expansion tank on it. In addition, install bypass taps so that you can disconnect it from the circuit during maintenance.
Now connect the boiler to the gas boiler according to one of the given diagrams. Don't forget to turn off the boiler and shut off the system before connecting!
Connect electronics, sensors, pumps according to the instructions.