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Connecting the safety group of the indirect heating boiler. The principle of operation and installation schemes. Schemes and rules for connecting BKN

2016-12-25 Evgeny Fomenko

Security kits for different companies

The safety group for an indirect heating boiler manufactured by Valliant consists of the following parts:

  • Check valve.
  • Two stopcocks, before and after the check valve.
  • Overpressure valve.
  • The union for connection of the manometer.
  • Drainer.

Connects to the water supply cold water. It is used for indirect type heaters Vaillant VED H 27/7 INT, VIR 150/5, uniSTOR VIH R 120 (read how to connect a temperature sensor to a Vaillant boiler). If the pressure in the water supply is less than 5 bar, Art. -No. 473, if the pressure is more than 5 bar - art. -No. 474.


If the water is too dirty, you need to install a filter in front of it. Buderus water heaters use the SG 160S safety group, which is usually supplied with the water heater.

It includes a number of details:

  • Body with check valves.
  • Descent switch.
  • Shut-off and replaceable check valve.
  • Safety valve.

The body and connections are made of brass resistant to disinfection. Can be installed both horizontally and vertically. When choosing a mounting location, you need to leave free access to the device nodes.

It is used with the following models: Buderus Logalux SM-200/5, SU200/5, SMH 400/5 W. Manufacturer Watts manufactures fittings and accessories for boilers and water heaters.


The Watts equipment set consists of several elements:

  • Automatic air vent.
  • Pressure gauge.
  • Safety valve.
  • Shut-off ball valve with 90 degree closing-opening stroke.
  • Water guide to prevent splashing.

The nodes are mounted on a steel console. Mounted in a vertical position above the boiler. The design is quite compact, made in a brass case. Once a month it is recommended to scroll the handle safety valve counterclockwise to flush it. Withstands water temperatures up to 120 degrees. Suitable for Baxi boilers. It is considered one of the most reliable manufacturers.

The Proterm set consists of a manometer with an aluminum dial with a range operating temperature from -30 to 120 degrees, air vent and safety valve. Indicates the current pressure in the system and, if necessary, drains excess fluid. When installing, you should take into account the direction of movement of the water flow, which is shown by the arrow.

The ACV kit, in addition to the safety group, contains a specialized mixing valve and expansion tank. Suitable for smart water heaters. If you decide to replace or adjust something, it is important to remember that the water exiting the device is hot and there is a risk of burns.

Meibes equipment additionally includes a decorative drain funnel, safety valve Meibes ME 6915B.80 PE 8 bar and control throttle. Suitable for devices up to 200 liters. Installation must be carried out by specialists.

If several boilers are combined in the system, OSO equipment is suitable. Designed for high blood pressure and having an additional backup valve.

Purpose

When heated, the water in the indirect heating device expands and exerts pressure on the walls of the tank. To prevent destruction and rupture, a security group is established. It allows you to control the pressure inside the tank and, if necessary, drain excess water.

When the water pressure reaches a certain limit value, which depends on the settings, the lock opens and the water drains automatically, reducing the pressure. It is also a protection against rupture of the case when the temperature sensor breaks and the water is heated too much.

If you do not install a safety group, in the event of a heater breakdown, the company may deny you warranty. It usually comes with the boiler, but you can also buy it separately. The price for it varies from 700 to 4000 rubles, depending on the parameters of the device and reliability.

One of the most rational and versatile devices capable of providing private house hot water, it is customary to consider indirect heating boilers. In this article we will talk about the economic justification, the principle of operation, the installation scheme and the features of the operation of these devices.

How an indirect heating boiler works

The device of the flask of indirect heating boilers is the same as that of electric or gas boilers: a stainless steel tank with an internal coating and thermal insulation. Instead of a heating element, a coil-heat exchanger is installed in them, through which hot water of the heating system flows.

It may seem that a temperature of 50-70 ° C will not be enough to heat water, because gas and electric water heaters have much higher rates. But due to the large area of ​​contact, the heating rate is not inferior to other devices, and sometimes it is even higher.

Indirect heating boiler device with a coil: 1 - cold water inlet; 2 - exit hot water; 3 - protective anode; 4 - input central heating; 5 - thermal insulation; 6 - heat exchanger; 7 - central heating outlet

Indirect heating boilers also have a sacrificial anode, but the safety group, as a rule, is not included in the design. Such simplicity of the device, on the one hand, is characterized by a long service life, on the other hand, it requires a thorough approach to drawing up a communications and piping scheme.

Boilers of indirect heating require a fairly spacious room for installation. They are mainly equipped with objects without an additional chimney or the presence of water heater in the gas supply project. In such cases, the only alternative is a double-circuit boiler, but in summer it is inconvenient to use it, and the re-equipment of heating and hot water systems can cost a pretty penny.

Varieties and selection of devices

In addition to tanks of an elementary design, there are also boilers of a more complex device that allow you to realize some wonderful functions when integrated into a heating system.

One of the most requested functions is the use of a boiler as a heat accumulator. This is especially important when electric heating with unstable power supply or when working at daily rates. Devices with a heat accumulator mode have a significant capacity (more than 300 liters) and reliable thermal insulation.

Boilers with a recirculation system that provide instant hot water to the mixer are considered more expensive. They have three connections to DHW system: one for cold water supply and two for hot water flow. Circulation is carried out by a small built-in pump. Boilers of this type are less economical, but they can be used to organize a small heating circuit, for example, to install a heated towel rail.

Some boilers have a tank-in-tank design, the name speaks for itself. The outer container contains the heat carrier of the heating system, the inner container contains the heated tap water. The advantage of this design is the very rapid heating of water, but due to the complexity of the device, such boilers are much more expensive than conventional ones.

Indirect heating boiler "tank in tank": 1 - cold water inlet; 2 - hot water outlet; 3 - central heating input; 4 - inner tank made of stainless steel; 5 - central heating outlet

What heating systems use boilers

Almost any heating unit can work in conjunction with indirect heating boilers, but the use of devices of different classes has its own characteristics. In general, than easier device boiler - the clearer the scheme of work, but the higher the complexity of the strapping. For example, for a standard chimney boiler with a thermostat, you can choose the insertion point yourself, depending on the configuration of the heating circuit. This is not so easy to do with the built-in heat pump, and boilers with electronic control may malfunction when working summer period.

Solid fuel and liquid fuel boilers cannot be used in summer, but in winter time this is one of the most acceptable options. They are also productive electric boilers heating, for greater convenience, they can be equipped with an additional thermocouple or automation with remote sensors to regulate the operation of the water temperature in the tank.

It is most difficult to connect an indirect heating boiler to gravity-type systems. With slow circulation, the water is not heated as efficiently, and in order to use the pump, it is necessary to correctly select the tie-in points into the heating system so as not to disrupt the heating operation. The correct solution would be a serial tie-in to the return line with the organization of a long bypass, in which the pump and the boiler are connected in series, and a check valve is installed on the flow branch.

Installation and piping scheme for an indirect heating boiler

There are three options for connecting to the heating system, and all of them involve installing a boiler at a minimum distance from the boiler. The boiler should be placed on a sufficiently solid foundation and strictly level. The coolant must be entered from above, discharged from below. Hot water intake, on the contrary, is carried out from above, and make-up - from below.

Option 1. The heating supply pipe is divided into two branches, each of which has a shut-off valve or a three-way valve. One branch passes through the boiler, the other short-circuits the line if water heating is not needed. This method is optimal for continuous use of the boiler or seasonal operation. In this case, the temperature can be regulated by two self-returning solenoid valves connected through a three-pin thermostat relay.

1 - cold water supply; 2 - shutoff valves; 3 - mesh filter; 4 - check valve; 5 - security group; 6 - heating radiator; 7 - heating boiler; 8 - boiler safety group; nine - circulation pump; 10 - three-way valve; 11 - solenoid valve; 12 - expansion tank of the DHW system; 13 - hot water to consumers

Option 2. The supply pipe has a branch to which a circulation pump and a boiler are connected in series, on the other hand, the connection is made to the return flow pipe. The pump is switched on via the thermostat relay circuit, so that when the temperature of the water inside the boiler drops, it activates forced circulation and accelerates heating. The heating circuit has its own pump installed on the supply pipe after the boiler tie-in. This option is optimal if the boiler is used infrequently or if the water temperature is required lower than in the heating system.

1 - cold water supply; 2 - shutoff valves; 3 - mesh filter; 4 - check valve; 5 - security group; 6 - circulation pump of the DHW system; 7 - boiler thermostat; 8 - radiator; 9 - heating boiler; 10 - boiler safety group; 11 - circulation pump of the heating system; 12 - expansion tank of the DHW system; 13 - hot water to consumers

Option 3. The boiler is connected in series with the boiler supply pipe through a circulation pump. With this connection, the boiler always works in the heat accumulator mode, the option is optimal for devices with recirculation. The presence of a bypass connecting the coolant outlet from the boiler to the boiler return makes it possible to use the hot water system in summer.

1 - cold water supply; 2 - shutoff valves; 3 - mesh filter; 4 - check valve; 5 - security group; 6 - bypass; 7 - heating radiator; 8 - heating boiler; 9 - boiler safety group; 10 - circulation pump; 11 - expansion tank of the DHW system; 12 - hot water to consumers

For any connection scheme, it is necessary to install shut-off valves on all pipes of the boiler and circulation pump. Connecting the boiler to the DHW system necessarily requires the installation of an expansion tank with a membrane on the water supply side to compensate for the pressure of the heated liquid. A strainer and a non-return valve must be installed on the cold water supply pipe to the safety group.

Operation and maintenance

Every 2-3 years the boiler needs a complex Maintenance by analogy with electric water heaters: washing the tank, removing scale, replacing the sacrificial anode when it is thinned by more than 50%, replacing gaskets. It is reasonable to carry out an inspection with the removal of the technical flange of the tank in the summer, in combination with the maintenance of the heating system. Flushing with chemicals of the heating circuit and the boiler heat exchanger must be carried out separately using appropriate cleaning agents. Otherwise, these devices are very unpretentious.

To provide the house with the necessary amount of hot water, an additional device is used - an indirect heating boiler (BKN). Its use can be considered one of the most rational and economically justified.

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

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

We will consider traditional boilers with a coil, using hot water as a heater.

Design features and principle of operation

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

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

Considering new models famous brands, then it can be seen that gas boilers and often have the same design. They are mounted next to each other or one below the other - this way you can save on space.

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

Schemes and rules for connecting BKN

The connection diagram and installation features of the indirect heating boiler depend on the class of the device and. It is necessary to choose the right installation site, focusing on the location of the boiler, the tie-in of the pumps and the existing wiring. Let's try to figure out what needs to be considered 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, a parallel connection occurs. heating system and BKN, equipped with shutoff valves. The boiler must be installed near the boiler, the circulation pump should be connected to the supply, then the three-way valve.

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

In the event of an emergency increase in gas or water pressure, a safety group is used to protect the heating system. Anyone who wants to protect their boiler or water heater from premature failure should buy a heating safety group. It is a combination of three devices - a pressure gauge, a safety valve and an air vent. A pressure gauge is needed to control the level of pressure in the system - the red arrow indicates the division corresponding to 3 atmospheres as the maximum pressure level. An air vent should be located at the highest point, which eliminates excess air in the system. Finally, the function of the safety valve in the safety group is to prevent excessive pressure in case the expansion tank does not work.

Boiler safety groups require correct installation otherwise, ill-conceived actions will lead to failure of the heating system. The safety group is installed on the supply in such a way that the shut-off valve is located behind it. If this closed system heating, it is necessary to arrange the safety group so that if one of the three elements fails, it can be easily replaced.

Boiler safety groups 3/4

Boiler safety group 3/4 made of brass- one of the most common and bought. In our catalog you will find safety groups with other connection diameters - 1, 1/2. The safety group for the boiler is installed at the cold water inlet in the direction indicated on the body. Any boiler has such a parameter as operating pressure, which depends on the pressure in the entire pipeline system. When heated, this pressure can increase by several atmospheres, and excess water will press against the walls of the boiler. The safety group controls the pressure in the boiler so that it does not rise above normal.

Buy a safety group for heating - prices

The price for the security group for the heating system is quite affordable, and it is also pleasantly combined with the impeccable quality of the goods. The compact combination of pressure gauge, safety valve and air vent is available to everyone and is necessary, especially if you use a boiler with a volume of more than 50 liters. To select and buy a safety group for the boiler, contact our specialists at the phone number indicated on the website.

All information on security groups - price, models and much more can also be found on the site.

Indirect heating boiler It is designed to provide a private house, dacha, enterprises with enough water. The principle of operation of the boiler is simple, however, the efficiency of this device depends on how correctly the indirect heating boiler is connected to the boiler.

An indirect heating boiler is purchased to work with a single-circuit boiler. Together, this equipment will take up more space than a double-circuit boiler. In families with a household of two or more people, flow heating systems will be ineffective, optimal solution— indirect boiler heating.

The capacity of boilers varies from 80 liters to several cubic meters. There are recommendations for selection of boiler capacity . For two people, this is the minimum tank that can serve two points of water intake at the same time. Three people need a 100-liter tank for three points of water intake. For four - it's 120 liters, and for five - 150 liters, etc. If the house is often washed in the bath, then a tank with a capacity of 120 liters is purchased. Please note that these figures are averages, as the need for hot water is very individual.

Boiler internals indirect heating is quite simple - service water heated by the coolant from the heating system passing through in a hot water tank.

It is preferable to purchase boilers with a stainless steel tank (for durability). Some characteristics are shown in the table below:

where, d is the difference between the inlet and the reached temperature. These characteristics can only be achieved if the input power of the boiler is not less than the specified power of the boiler heat exchanger! It should also be noted that the temperature of the incoming water in winter and summer will be different (from +5C to +15C).

There are also boilers with a system that have a self-cleaning function from scale. It is provided by the shape of the internal tank in the form of a corrugation.

The characteristics of such boilers are shown in the following table:

As already mentioned above, the output characteristics directly depend on the power of the boiler itself. Thermal power the boiler should not be lower than the capacity of the boiler, otherwise the amount of heated water will be less than declared. And if the power of the boiler exceeds the power of the boiler, then the amount of heated water will be the maximum possible, based on the power of the boiler itself. For example, if you purchased a 31 kW boiler and you need a 100 liter boiler, then the best purchase in this case would be a boiler with a coil, because the capacities of these units are ideally matched for best performance - 30 and 31. A boiler with a “tank in tank "23 kW will not be able to master the full power of the boiler and the characteristics given out by it will be less than in the first case. If you bought a 24 kW boiler, then in this case it is better to take a boiler with a tank-in-tank system, since in this case the maximum DHW performance is achieved, and the boiler with a coil will have power losses.

Most engineers consider that tank-in-tank boilers are preferable. Due to self-cleaning, durability is achieved, and due to internal device the heat transfer area is increased, which results in increased productivity. Therefore, in most cases, such boilers are preferable. Although simple ones are considered cheaper in cost. And in general, if you have chosen a simple boiler - this is not bad at all.

The following diagram shows an example location stop valves and protection devices connecting an indirect heating boiler to a floor-standing boiler adapted for its connection - with the ability to control pumps. Basically, these are volatile boilers of foreign production.

When an indirect heating boiler is connected to a non-volatile boiler, such as domestic AOGV or KSG, the boiler pump is controlled from the boiler thermostat. At the same time, it should be noted that the water heating rate is significantly reduced, since the boiler power is distributed between the heating circuit and the boiler.

Before the boiler at the cold water inlet, it is obligatory to install safety relief valve by 6 - 8 bar, depending on the characteristics of the boiler (example in the photo below. Here is a relief valve with a check valve assembly).

Boiler safety group Watts 3/4 for 7 bar (10004611)

Everyone knows that when you turn on hot water, for some time it comes out of the tap cold. This problem is solved by installing groups without boiler safety with an additional weak pump. Many manufacturers offer such pumps. The following diagram shows an example of installing a recirculation line:

Please note that the above diagram is applicable to boilers equipped with a recirculation outlet. If there is no such output, then the scheme will look like this:

Here we see the recirculation line cutting into cold water after the check valve and safety group. On it, after the pump, another check valve crashes to prevent cold water from entering the recirculation.

In general, when connecting an indirect heating boiler for hot water supply in the house, we will get the same comfort as in a city apartment with central water supply with an advantageous difference in its cleanliness. Such water can be used for food purposes, even poured into a kettle without harm to health.