Ceiling

Proterm indirect heating boiler connection diagram. Connecting an indirect heating boiler

If you don't know how to connect the boiler indirect heating to a double-circuit boiler, the diagram on this page will help you deal with this issue.

The most simple circuit Connecting an indirect heating boiler to a double-circuit boiler involves using the second circuit of the boiler to heat hot water for domestic hot water.

In the case when you do not have a BKN, hot water is heated in a “stream” mode. If you need a “cumulative” mode, then there is only one option - using BKN, since there are no storage tanks There is no hot water storage.

In this case, the double-circuit boiler, the diagram of which is given on this page, is implemented in exactly the same way as if it were a single-circuit boiler.

The question arises - why then use a double-circuit boiler? The answer is not obvious. But someone may have a situation where they already have a 2-circuit boiler and have a BKN. And at the same time, a person wants to implement a hot water supply system in “accumulative” mode.

Connection diagram for an indirect heating boiler to a double-circuit boiler

So, here is a simple diagram for connecting an indirect heating boiler to a double-circuit boiler, when you have the opportunity to implement a “storage” mode for the hot water system even when using a 2-circuit boiler.

Installation with a single-circuit boiler

There are two main schemes for connecting an indirect heating boiler to a single-circuit boiler:

Connection to a double-circuit boiler

The double-circuit boiler itself is designed for both heating and hot water. But usually there is only enough water from it for one watershed point. An indirect water heater allows you to increase the amount of hot water produced.

You can connect it in the same way as to a single-circuit one using a three-way valve or two pumps. At the same time, route the pipes to different watershed points, for example, from the boiler to the washbasin, and from the boiler to the shower.

In the second method, the water heater is used as storage buffer capacity. Hot water from the boiler enters the tank, where it is heated further if necessary. A more uniform temperature of the liquid will also be a plus.

Solid fuel boiler and central heating

Connecting the indirect heating device to a solid fuel boiler is carried out according to similar schemes. The solid fuel boiler allows you to install thermostatic valves on the radiators. This makes it convenient to regulate the temperature in the room, but there is a danger of the boiler overheating.

To prevent this from happening, companies install an emergency heat exchanger, which leads to loss of energy. If an indirect heating water heater appears in the system, it provides protection against overheating and excess heat is not wasted.

If your apartment's radiators are consistently heated in winter, you can connect to central heating. In this case, you should take a combined boiler with a removable heating element so that hot water remains in the summer, for example, OKC 125. Here it will not be possible to set the priority for heating the water supply, since the riser is not yours personally, but the whole house. A circuit with a circulation pump is suitable here.

Recirculation system

If you intend to have a heated towel rail, you should purchase models with recirculation, for example, Drazice OKC NTR/Z. There is a recirculation point in the center of the tank. This makes the heated towel rail constantly warm and the water in the tap immediately hot. You won't have to wait for the cold water to drain.

The disadvantage of such systems will be the loss of thermal energy. Also, in schemes without recirculation, the heated water is located on top of the tank and from there it goes to the water collection points. This allows you to use the maximum amount warm water. Recirculation mixes the water layers in the tank, so this effect is partially lost.

Installation of systems

You can install and connect an indirect heating boiler yourself. To begin with, a connection diagram is selected depending on the needs and hardware.

After this they are purchased necessary materials: three-way valve, pumps, metal-plastic pipes, tees, valves and check valves. Next, the location for installing all the nodes is selected and a plan is drawn with reference to the room.

Installation consists of the following main steps:

We invite you to watch a video about connecting an indirect heating boiler:

How to connect a boiler to a boiler? Connection options and diagrams

How does the DHW function work in heating system boilers?

For example, you have one boiler in your heating system and you need to make sure that you also heat water with this boiler for hot water supply.

What methods are there for heating water through a boiler?

We will look at 5 schemes and tell you how each scheme works. Let's consider the advantages and disadvantages of each scheme.

Scheme of work No. 1. Dull coolant intake from the boiler

Do not use a blunt water intake from the boiler! It's not very economical DHW system, if the boiler temperature does not exceed 60 degrees.

Well, firstly, the boiler temperature can be set to 50 degrees. At this temperature, you will not be able to heat the water in the boiler above 48 degrees. Secondly, heating will take a very long time, since heat transfer drops greatly if the temperature of the water and coolant do not differ greatly. That is, to quickly warm up, you need to use a high temperature difference. 90-60=30 degrees. Because of this, indirect heating coil boilers use an increased coolant temperature.

There are indirect heating boilers, tank in tank. This method uses a large heat exchanger area upon contact (coolant-DHW).

Such boilers have a much higher heating rate than a snake. This is achieved by increasing the contact area (coolant-DHW). And also due to the fact that the heat transfer limit is increased. Such a boiler increases the intake of more power due to the preservation of the coolant in the boiler, which has an inertial nature of maintaining temperature. Due to this, the very cooled coolant is immediately taken from the external tank. This process accelerates the extraction of thermal power to heat water. In this case, you can use the boiler, provided that the boiler temperature is 60 degrees or more. If the boiler temperature remains at 40-50 degrees, then you will have low temperature in the boiler.

I would like to draw your attention to the accumulation of hot water. If you have heated water in the tank at 45 degrees, then you, for example, will have 10 minutes to wash with normal water in the shower. If your boiler temperature is 90 degrees, then you will be able to use the shower for more than 60 minutes. That is, by increasing the temperature, you increase the accumulation of hot water in the boiler with the same capacity. That is, the volume of hot water use will increase.

If you are not satisfied with the change in temperature in the boiler, which changes over time and you have to reconfigure. Then there are special thermostatic valves for domestic hot water. They are called thermostatic mixing.

This scheme allows you to always obtain a stable temperature at the outlet for DHW consumption

Work scheme No. 2. Crutch method. We increase the boiler temperature.

According to this scheme, we simply set the boiler temperature, for example, 80 degrees, and the heating system will receive, for example, 60 degrees. By mixing it with the cooled coolant back and forth, the set temperature will be achieved.

I can't say how good this method is. On the one hand, they say that the boiler efficiency becomes higher if the coolant temperature is 60-80 degrees. This is due to the fact that at such temperatures chemical combustion is better and the gas burns better. That is, at low temperatures the gas does not burn out. That is, particles of combustible material are not completely released thermal energy. But for condensing boilers this efficiency rule does not work. There they specially lower the temperature of the coolant to 55-45 degrees.

On the other side high temperatures increase scale in heat exchangers and pipes, which in the future can lead to a decrease in power and failure of the boiler due to overheating. Also, build-up appears more often on steel pipes with high-temperature coolant. That is steel pipes overgrown.

What's wrong with this scheme? It becomes bad compared to other DHW connection schemes. Well, for example, in some boilers there is weather-dependent regulation - equithermal mode. Also, when there is a need to turn off the boiler for heating and keep it running on DHW (automatically), it is problematic to do so. Because there are boilers with a heating shutdown function room thermostat, and the DHW function remains operational.

Work scheme No. 3. Buy a ready-made double-circuit boiler and do not use a DHW boiler

Such a double-circuit boiler has an additional heat exchanger for domestic hot water inside the boiler. That is, the first-main heat exchanger is for transferring heat from the burning gas to the coolant.

Cold water passes through a plate heat exchanger under pressure from the water supply system. On the pipe line water supply DHW there is a flow sensor. The flow sensor triggers a cascade of actions: Switches to redirect the flow towards the plate heat exchanger, and the coolant temperature also increases due to an increase in gas in the heater. That is, during DHW preparation, the heating circuit is switched off. And the movement of coolant through radiators and heated floors is turned off. During DHW, the coolant inside the boiler begins to circulate water through the DHW heat exchanger.

What does a double-circuit boiler with isolated circuits mean? This is when the water supply circuit and the heating circuit do not interact in liquid. That is, liquids do not mix and liquids do not transmit pressure. Only temperature is transferred from one liquid to another liquid.

Water passing through a plate heat exchanger quickly heats up, usually to a maximum of 60 degrees. This temperature in some boilers is regulated only up to a threshold of 60 degrees. That is, the temperature cannot be raised above 60 degrees. This temperature is usually programmed and cannot be changed. Check with the manufacturer. Also in the passports are instructions for use.

Such a scheme with such a boiler is not suitable for high productivity. That is, it is problematic to service two or three appliances (sink, bath, shower). There's just not enough power. If you want to service several sanitary appliances (sink, bath, shower) you will have to install a storage tank. Making a storage tank for such a boiler is problematic. Next, we will consider schemes with hot water storage tanks.

Disadvantage of receiving hot water? The hot water temperature will not be stable when the flow rate through the heat exchanger changes. There will be fluctuations in hot water temperatures. Practice has shown that with high flow rates, water may not heat up to the required 60 degrees. It happens that it doesn’t reach 45 degrees. Well, it depends on the power of the boiler and its response speed. Of course, in my practice I have come across boilers that respond well to heating water. The problem is that you have to wait for the water to become hotter due to the fact that the boiler takes a long time to think when it will switch to heating the water.

Also, such a boiler does not allow DHW recirculation.

Work scheme No. 4. DHW accumulation through an indirect heating boiler.

Electrical diagram for connecting DHW to the boiler

The passport instructions must indicate electrical diagram. Usually they indicate the letter marking and, having opened the boiler lid, you need to look for the letter marking for the DHW in the electrical board. In some passports in the electrical diagram they may be called DHW or boiler thermostat or something else. It rarely happens that they will draw a board to scale and show where the contacts are.

How can the electrical diagram of a boiler be indicated:

Sometimes there may be more than two contacts for DHW. Again this is done for greater functionality.

Also pay attention to whether there are contacts for pumps. There may be a contact for the pump to the DHW boiler.

Sometimes the boiler can use additional terminals for additional functions for your heating system. For example, you have a pump and it needs to be turned off when the boiler is turned off. That is, it is necessary to create a fully automatic system so that the client does not fool himself with additional operations. That is, if you turn off the boiler, then everything related to heating should turn off automatically.

Usually you need to take two conductors from the boiler and lead it to the thermostat on the boiler relay:

The boiler has two DHW conductors that can have a simple alternating voltage of 220 volts. But this should always be checked, perhaps there is a reduced voltage there. And you cannot run 220 volts independently from the sockets and connect them to the hot water supply line from the boiler. It is assumed that the DHW boiler contact comes to a dry contact to the boiler thermostat or to another short circuit contact. The boiler thermostat is electrical relay, which changes the position of the contacts depending on the temperature of the water in the boiler.

Also, the boiler may have more than two conductors for DHW. For example, you may need constant voltage 220 Volts for powering pumps and more. The electrical circuit of the boiler may contain special conductors for control. This is again done for better functionality. If you turn off the boiler, then everything connected to the boiler should turn off along with the boiler.

An indirect heating boiler may have a larger circuit with all sorts of additional functions, for example, for illuminating lamps signaling the operation of a boiler and much more.

But you need to understand the scheme in a simple way. And here's what you need to understand:

Almost all indirect heating boilers use a changeover contact and can be used as a dry contact. A switching mechanism that transfers contact from one conductor to another. Thus, we must connect the DHW function from the boiler to this contact. And the boiler will do the rest itself: Switch, which is built into the boiler. And it will add temperature to quickly heat the water in the boiler. Some sophisticated boilers may have timer protection when the boiler heats up in time beyond what is reasonable. In this case, the heating system may freeze. This may occur due to the failure of the boiler thermostat. Or due to the fact that the temperature on the thermostat is set higher than the boiler produces, and the boiler can never heat up to the set value.

But the schemes are different, and it happens that a pump needs to be installed on an indirect heating boiler. And the boiler does not have the ability to power the pump to the boiler. There is a connection diagram for this.

Contactor– an electromagnetic relay that switches the contact due to another signal - a voltage of 220 Volts.

It may be possible to use the DHW contact to immediately give a command to the DHW and power the circulation pump. Check with the manufacturer or read the instructions for use. Also look for an electrical diagram for connecting the boiler to the boiler.

If you want help developing a connection diagram and selecting necessary elements, then you can ask for help. But I’ll say right away that it’s not free.

Scheme of work No. 5. Accumulation of hot water through an indirect heating boiler in a single-circuit boiler

Many plumbers may be mistaken in the fact that if the boiler is single-circuit, then it does not have a DHW function.

However, single-circuit boilers with DHW function exist! Moreover, in some boilers they will even prepare contacts for you to connect to redirect the coolant flow towards the indirect heating boiler. Connecting the pump to the boiler and much more!

This method is suitable for those who want to assemble a heating system themselves and come up with their own methods automatic system. That is, if the above schemes do not suit you, then you can take a single-circuit boiler with a DHW function and add any scheme convenient for you with three-way valves and pumps. For example:

Conclusion on the most worthy scheme for using hot water supply

Schemes 4 and 5 are the highest priority schemes for the preparation of hot water from boiler equipment!

Advantages of schemes 4-5:

1. Fast heating of hot water. By increasing the boiler temperature. This happens automatically. That is, the system operates at one temperature, and when the DHW function is turned on, the temperature rises to 90 degrees.

2. In many expensive wall-mounted boilers weather-dependent regulation is used. It is also called the equithermal mode of operation of the boiler. That is, the coolant temperature changes depending on the weather outside. Therefore, such a boiler in combination with DHW best solution. Because you are unlikely to be able to do such functionality with the DHW function with a boiler or circuit without DHW.

Disadvantage 4-5: This is a heating shutdown when the hot water supply is running. But it's not so scary. Because some sophisticated boilers have protection against heating shutdowns caused by long warm-up of the hot water supply. The DHW function simply turns off after a certain time to turn on the heating of the house.

Subscribe to receive new articles. There is a form below, just enter your Name and E-mail and confirm your subscription. And you will receive useful articles.

Comments(+) [ Read / Add ]

A series of video tutorials on a private home
Part 1. Where to drill a well?
Part 2. Construction of a water well
Part 3. Laying a pipeline from the well to the house
Part 4. Automatic water supply
Water supply
Water supply for a private house. Operating principle. Connection diagram
Self-priming surface pumps. Operating principle. Connection diagram
Self-priming pump calculation
Calculation of diameters from central water supply
Water supply pumping station
How to choose a pump for a well?
Setting up the pressure switch
Pressure switch electrical diagram
Operating principle of a hydraulic accumulator
Sewage slope per 1 meter SNIP
Heating schemes
Hydraulic calculation of a two-pipe heating system
Hydraulic calculation of a two-pipe associated heating system Tichelman loop
Hydraulic calculation of a single-pipe heating system
Hydraulic calculation of radial distribution of a heating system
Scheme with a heat pump and solid fuel boiler - operating logic
Three-way valve from valtec + thermal head with remote sensor
Why the heating radiator in an apartment building does not heat well
How to connect a boiler to a boiler? Connection options and diagrams
DHW recirculation. Operating principle and calculation
You are not calculating the hydraulic arrows and collectors correctly
Manual hydraulic heating calculation
Calculation of warm water floors and mixing units
Three-way valve with servo drive for domestic hot water
Calculations of hot water supply, BKN. We find the volume, power of the snake, warm-up time, etc.
Water supply and heating designer
Bernoulli's equation

Indirect heating boilers in private homes can be supplemented with both gas and solid fuel boilers or diesel boilers. Installing this type of equipment can make living in a country house much more comfortable. Unlike double-circuit boilers, boilers are able to provide the most uniform heating of water.

What is an indirect heating boiler and how it works

The design of units of this type is relatively simple. It is an indirect heating boiler, a small heat-insulated metal “barrel”, coated on the inside with two layers of enamel. As heating element in such units a conventional coil is used.

Cold water enters the indirectly heated boiler from below, passes upward through a spiral, heats up and exits out through the upper pipe. The heating fluid of the heating system is responsible for heating the coil itself in such devices. Hot water from the boiler is supplied to the heating coil from above and removed from it from below.

What rules should you follow when connecting?

Do-it-yourself piping of indirect heating boilers is carried out in compliance with the following recommendations:

taps are installed on the pipes supplying coolant to the coil and discharging it;
at the entrance cold water a check valve is installed in the unit;
An expansion tank must be used in the boiler piping.

Taps on the pipes connecting the water heaters to the boiler are installed to facilitate repairs if necessary. If such fittings are present, it will be possible to remove the unit at any time in the future without turning off the main equipment. When installing a boiler, a check valve is used to prevent hot water from entering the “cold” water supply when the pressure in the system drops.

The expansion tank in the piping of indirect heating units serves to prevent rupture of their housing during operation. After all, as you know, when heated, water can expand quite strongly. Consequently, the pressure inside the unit can increase to high limits.

Main stages of installation

The water heater wiring, therefore, should include the following steps:

connecting the unit to the water supply from the well;
insertion of a pipeline supplying heated water to consumers;
connecting the coil to the boiler pipes supplying and discharging coolant;
installation of an expansion tank and a safety group.

Along with the boiler, a recirculation system is usually installed in boiler rooms, increasing the convenience of using hot water supply.

Step-by-step installation of a boiler in a forced-type heating system

In networks of this type, piping of indirect heating units is carried out as follows:

after the circulation pump, a three-way valve is cut into the supply pipe;
a water heating temperature sensor is screwed into the sleeve on the boiler body;
one of the outputs of the three-way valve is connected to the coolant receiving pipe of the boiler;
a tee is cut into the return pipeline;
the coolant outlet pipe of the coil is connected to the tee;
a valve is installed behind the tee;
An expansion tank is mounted on the hot water pipe next to the boiler.

Indirect heating sensors are usually initially supplied with single-circuit boilers. When the water in the boiler cools, they simply switch the three-way valve to supply coolant to its coil. As a result, the boiler switches to hot water heating mode. Heating system at the same time it turns off for a while.

As soon as the water temperature in the boiler reaches a certain value, the three-way valve again switches the boiler to space heating mode.

Stages of installing a water heater with a pump

Sometimes indirect heating boilers, when inserted into the system, are supplemented with their own circulation pumps. Typically, this piping scheme is used when the unit is installed not next to the boiler, but at some distance from it.

In this case, installation is carried out using the following technology:

a pipe supplying coolant from the boiler is connected to the boiler coil from above;
a section of the boiler return line cuts into the line supplying cold water to the boiler;
Before these sections, a check valve is installed in the cold water pipe;
a pump is installed on the heater return;
the pipe is connected to the coil;
an expansion tank is installed.

A three-way valve, as you may have noticed, is not used in such a scheme. The boiler circuit is connected through ordinary tees. For switching the stream to in this case The pumps and temperature sensor respond, closing the contacts of the boiler or boiler pump depending on the degree of water heating.

Step-by-step strapping in gravity systems

The water heater is installed in networks of this type in such a way that it is located above the radiators. Therefore, they usually purchase not floor-mounted, but wall-mounted suspended boilers for gravity systems.

Includes correct installation water heaters in networks with natural circulation of coolant, the following steps:

the supply from the boiler is connected to the boiler coil using a pipe of a larger diameter than in the heating system;
then the heating system supply is cut into this segment between the boiler and the water heater;
between the boiler and the resulting branch, a thermostatic head with an attached sensor, powered by batteries, is mounted;
the boiler is connected to the boiler by a return pipe;
a line for discharging cooled coolant from the radiators is cut into the return pipe;
An expansion tank is installed closer to the boiler on the return line.

When using this scheme, water is heated due to the difference in the cross-section of the supply pipes of the boiler and the heating system. The water heater in this case is a priority. As soon as the water in the boiler warms up to a certain temperature, the sensor is triggered and the pipeline is closed. As a result, water begins to flow into the heating system.

Is it possible to connect to double-circuit boilers?

It is quite convenient to use double-circuit boilers that can heat water both in the heating system and in the hot water supply system in country houses. However, this equipment has one rather serious drawback. When using a double-circuit boiler as a heater, the water from the DHW taps may either be too hot or too cool. Equipment of this type, as already mentioned, is not capable of providing uniform heating.

The situation in this case can be corrected with the help of a boiler. Connect such equipment to double-circuit boilers, of course, is allowed. The water heater is connected to such units in the usual manner. In this case, on the boiler itself the pipes responsible for the hot water supply are simply blocked.

Installation of an indirect heating boiler in a collector network

In such modern systems water heaters are also very often used. Boilers are usually installed in collector networks on the comb as close as possible to the supply. That is, where the coolant has the highest temperature.

Indirect heating boilers are connected in such systems according to the following scheme:

the supply from the heating system comb is connected to the water heater;
the return line, expansion tank, and safety group are connected;
water supply and discharge pipes are installed.

When installing the coil supply line in collector systems Shut-off valves are required.

Installation instructions for the recirculation system

It often happens that plumbing fixtures are located in the house at a considerable distance from the boiler or on the upper floors. In this case, the owners of the building usually have to wait until the water that has stagnated and cooled in the pipes drains from the taps in the bathrooms to get hot water. And this, of course, is inconvenient and not particularly economical.

This situation can be corrected by assembling in country house recirculation systems. Installation of such a network is carried out approximately as follows:

a tee is cut into the pipe supplying hot water to the consumer as close as possible to the consumer;
a pipe of the required length is connected to the tee;
the extended line is connected to the boiler through the recirculation pipe;
Next to the boiler, at the nozzle, an additional pump of not too high power crashes into the circuit.

When using such a scheme, the water in the pipes between the boiler and the consumer, after turning on the pump in the electrical network, will not stagnate and, accordingly, will be cooled. That is, use hot water Residents of the house will be able to immediately after unscrewing the tap valves.

Many people, having problems with central hot water supply in an apartment or house, decide to install an indirect heating boiler. It is considered economical and convenient to use. But how is an indirect heating boiler connected? There are several basic methods that are suitable for both apartments and country houses.

What is this?

An indirect heating boiler is a cubic or cylindrical container, inside of which a heat exchanger is installed, in most cases made in the form of a spiral coil. The coolant from the heating system passes through it, with the help of which the water in the tank is heated. Such systems are well suited for small homes.

In most cases, a water heater does not have its own heat source. It uses external heating energy. It could be central system or a separate boiler. Therefore, for each case, its own connection diagram for an indirect heating boiler is used.

Heating connection

Such water heaters are mounted to the heating and water supply system. For everything to work well, you need:

bring cold water to the bottom of the unit;
ensure that hot water comes out from above.

In this case, heating is supplied in such a way that the coolant moves downwards. It turns out that the hot flow enters through the upper pipe, and the cold flow comes out through the lower. It is through this connection that high efficiency can be achieved.

Connection via three-way valve

This type of connection is based on two circuits:

heating;
heating.

By using a three-way valve, an even distribution between the two lines is ensured. The main priority is the water supply system, and only then the heating.

In this case, there is no need to control the valve - everything works automatically. For this purpose, a thermostat is provided, which, when cooling, switches the valve, and water from the heating system is supplied to the heater. When the heater temperature rises to the required level, again the direction of movement of the liquid changes, and it is supplied to the radiators.

In most cases, installation of an indirect heating boiler is carried out in this way. The fact is that the system is simply irreplaceable when used large quantity water in the house.

Important! When setting the thermostat response limits, you need to take into account to what point the liquid in the boiler will be heated. Therefore, it is recommended to set the temperature on the device slightly lower than on the heating unit. Otherwise, the latter will have to work almost constantly on the water heater.

Using two pumps

Another good option is to install a check valve and two pumps. In this case, each unit is controlled by its own pressure generation unit. The indirect heating boiler is connected to the boiler in parallel to other components, but has priority.

Circulation pumps are installed in front of the water heater and heating system. For control, a temperature sensor is used, which sends appropriate signals to the devices.

Such a system is considered very suitable for heating based on two boilers. In this case, one of them completely transfers energy to the radiators, and the second has an outlet to the water heater.

When the liquid in the water heater cools down, the coolant is sent for heating, and when the temperature rises to the desired level, it switches to heating. A check valve is used to prevent coolant flows from mixing with each other.

And there is no need to worry that this will affect the heating of the room. The water in such boilers heats up quickly – in less than an hour. Therefore, the room simply does not have time to cool down.

Connection with hydraulic boom

Connecting a boiler to a double-circuit boiler using pumps is often done using a hydraulic arrow. Typically, such circuits are built into multi-circuit systems.

Mostly similar option used if there are several heating segments. This could be a hot water boiler, radiators, heated floors, etc.

Here the hydraulic module and manifold are configured. This will eliminate possible pressure drops in different parts networks.

Of course, you can install balancing valves. But this requires special skills and experience. In addition, it may become difficult to use in the future.

Return circulation

This scheme is implemented if a third input is placed in the tank. It is to this that the coolant recirculation is connected. The main purpose of this system is to increase the rate of supply of heated water. As planned, it should be supplied instantly - when the tap is opened. This way there will be no excess fluid consumption at the moment when draining occurs.

It turns out that a looped highway is created along which the flow constantly moves. It is controlled by a circulation pump.

For proper operation installation of an indirect heating boiler, and some additional components, including:

Check valve. It is installed at the inlet of the water heater. This prevents coolant from entering a cold pipeline when pressure increases as a result of overheating of water.
Automatic air vent. It is located in front check valve. This element is necessary to prevent excessive air from entering the pump before it starts.
Safety valve. Protects the heater from pressure surges.
Expansion tank. This component will maintain constant pressure even when the taps are turned off.

Important! IN expansion tank the pressure should not exceed the values set for the safety valve.

An indirect heating boiler is considered the most economical unit of the entire family of heaters. At the same time, there are several options for connecting it to different networks. You just need to compare with already installed heating and choose the appropriate one.