Diagrams of connection of an indirect boiler to the boiler
Indirect heating boiler can be connected to any source of energy that heats the liquid coolant and gives it a circulation. The most typical connection is to the house heating boiler (diagrams attached). But the boiler can also be heated by a heat pump, solar collector, separate heat generator, centralized heating system.
Some models of indirect boilers can contain not one heating coil, but several, and are designed for connection to several sources of energy.
For example, in Europe it is a matter of course if the boiler is heated by the solar collector and the boiler. And the boiler is an auxiliary element when you need to heat quickly, or when the sun’s energy is not enough.
It is important that in summer to heat water for household needs boiler does not need to be turned on (burned), and solar energy is enough.
But at the same time models with multiple coils are more expensive. So when choosing. you need to decide what scheme of connecting the boiler is used, how many energy sources will be involved and what.
Additional heater. an electric heater
In most cases we limit ourselves to the simplest models with one coil inside, heated only by the boiler. As a normal option. the presence of an electric heater, but the increase in price is negligible. The purpose of an electric heater is the same. to heat water when the boiler is not working.
Also indirect heating boilers differ on control automatics, it either is absent at all or is added for hinged installation, or is built in a boiler.
Scheme of heating with a boiler of indirect heating
Indirect storage water heater connection diagram with a floor standing boiler via a hydrostrelka looks as follows:
For floor boilers requires the connection of additional automation for proper operation.
The scheme is simplified if the indirect heating boiler is connected to a boiler Protherm, Vaillant etc.
This manufacturer has taken care of its users as well as possible and sells additional three-way valve (Fugas). Which connects to the built-in automation and allows for no collectors, hydrostems, etc. To make a complete DHW system using a storage water heater of indirect heating. In this case, everything works very reliably and clearly.
This is the solution deserves more attention because it does not require any special knowledge of programming, hydrodynamics and everything else.
Scheme to connect the boiler indirect heating to boilers Phroterm (gas, electric) will look as follows.
This diagram is taken from the user manual of these boilers. The only thing not shown in the diagram is the expansion tank for the boiler.
It is necessary to cut in an expansion tank at the place where there is a safety group. The volume of the expansion tank must be 0,1 volume of the boiler t.е. 10% of its liters. In addition, the safety valve should not be installed for the heating system (it is designed for a pressure of 3 bar), but for a water supply system with an operating pressure of 8 bar. On sale there are complete safety groups for indirect water heaters with already installed pressure gauge, safety valve and air vent. They are conveniently mounted on the wall. The expansion tank is installed on it.
Another nuance in the use of an accumulating indirect water heater. It must be heated periodically to a temperature of over 60°C. Celsius. This will prevent the formation of bacteria in it. Legionella is considered the most dangerous. It reproduces very actively in warm water. At low concentrations it is safe for the human body, but at high
Automatics of the boiler allows for such preventive maintenance, but if installed incorrectly, you can breed this trash in your boiler constantly. Keep it in mind.
This also applies to two-circuit boilers, although to a lesser extent. In the case of a long absence of water movement should be drained into the stagnant in the beginning.
How to connect an indirect water heater to a single boiler
System Boiler & Unvented Hot Water Cylinder Installation
- Diaphragm expansion tank. designed to compensate for thermal expansion in the DHW system and prevent emergencies. When connecting the BKN is installed together with the safety group. The expansion vessel must contain at least 10% of the total volume of the indirect heating boiler.
- The safety valve. is necessary for emergency drainage of water from the boiler. If the pressure is too high it opens and drains the water from the boiler. The valve is used during maintenance, to pour chemical reagents into the storage tank to remove limescale.
- Indirect heated boiler safety group. includes a pressure gauge, bleeder valve and air vent. The unit is designed to normalize the pressure in the DHW and prevent hydraulic shock. Installation of the safety group and the expansion tank, this is a requirement imposed by the manufacturers to BKN piping.
- Boiler temperature sensor. connected to the circulation pump, which controls the pressure in the coil. The immersion thermostat operates on the principle of a relay. When sufficient water has been heated the sensor gives a signal to turn off the pumping equipment. Water stops being heated. After cooling down, the automation for the boiler starts the circulation.
- Three-way valve. works as a subassembly, opening and closing the water flow to the boiler from the heating system. There are simple mechanical devices and accurate three-way valves with servo.
- Circulation pump. one or two modules are installed, depending on the wiring scheme chosen. The pump is used to create a constant pressure and recirculation in the DHW system.
Piping material for tap water systems
- Cold water. a normal polypropylene pipe can be installed. Material is suitable for soldering of the entire DHW system.
- Hot water supply. the temperature of DHW supplied to the user is maintained at 65-70 °. It is allowed to use polypropylene with glass fiber (reinforced) or aluminum reinforcement, designed for hot water supply.Another option: perform piping with copper pipe. When laying a copper pipe must use insulation. Copper is a good heat conductor, which will inevitably lead to a decrease in the temperature of heated water during transport to the end user. Thermal insulation of pipes will protect against heat loss.
Wiring options for indirect heating boiler
Another important factor to consider when choosing the type of connection. energy dependence. There are gravity systems, in which the circulation of water and coolant independently, as well as schemes with the creation of forced pressure (pump). The latter can not work without electricity. The manufacturers of BNH indicate in the instruction manual the recommended wiring diagram, which is also taken into account when connecting.
How the indirect water heater works?
The indirect heating boiler looks like this in the cut.
It consists of a storage tank, which is insulated and prevents the transfer of heat into the environment. Heat exchanger. the coil (usually copper) through which circulates the coolant heating system. Cold water inlet. The outlet of hot water (there can be several at different levels to create a system of hot water circulation). Temperature regulating sensor. It is also possible to complete the boiler anode, thermometer, built-in electric afterheater.
When the indirect water heater is hot
The coolant from the boiler circulates to the heating system (radiators and floor heating). The automation system shuts off the boiler heating circuit and all power is used to heat the house. If there is a DHW circulation, it operates in the normal mode and constantly refreshes the hot water on the floors and in the towel racks.
When the indirect water heater is cold
When the indirect storage water heater cools down, the temperature sensor turns on (circulation pump, three-way valve or other) the water heater is cooled down. automatics). All coolant begins to circulate (at least so should be at a proper installation of the system) through the heat exchanger of the boiler.
In this case, the boiler from the normal mode goes to the mode of increased temperature 70. 80 gr. (It is necessary that the boiler maintains this function). If this does not happen and the boiler remains in the 40gr mode. then very soon you will freeze t.к. the boiler does not heat up the boiler to the required temperature and circulates constantly through the boiler. The automation will not switch back to heating.
When heating a HUW cylinder with a recirculating system, the automation system must also switch off to heat the water as quickly as possible.
If everything is properly installed, the water heater will soon heat up. The thermostat will trip and the boiler will continue to heat the house. The recirculation system will be activated, and the boiler will.д.
Summer mode of the storage water heater of indirect heating.
In summer, when the heating of the house is not required. On the boiler. if it is a wall-mounted, turn off the heating of radiators to a minimum value. When the boiler is turned on, the boiler will only start heating.
Floor standing boilers have the “Summer” function. The principle is the same.
Two simple wiring diagrams
Indirect water heater connection diagram.
This scheme of connecting the boiler can be conditionally called the simplest. This is how you can connect DHW if there is only one main circuit in the room. For example, only the radiators or only the floor heating. This circuit is made so that the DHW has priority over the main circuit.
At the outlet of the boiler there is a three-way valve, which is controlled by a temperature sensor (thermostat) of D.H.W., installed in the boiler, which makes this circuit a priority. The valve changes the direction of the coolant, connecting it to either one or the other circuit. Sometimes the valve is controlled by signals coming from the main boiler, but the DHW circuit priority does not change from this, as the boiler controls react to signals also coming from the boiler thermostat.
Can You Connect a Wood Burner to Central Heating?
This scheme is good for wall hung gas boilers with a circulation pump. This scheme is also useful when the incoming water is very hard. In this case, use a two-circuit boiler, one circuit which operates only for domestic water heating, should not. Connect the second boiler circuit to such water, knowing full well that it will quickly fail, it is impractical.
Boiler connection diagram with circulation pump.
Connection scheme with two circulation pumps, which can also be conventionally regarded as the simplest. One of the pumps is constantly in operation, but in this variant the priority of DHW is retained, as the pump can be connected only by the signals of the thermostat, which reacts to changes in the boiler water temperature.
At the outlet of each pump there is a check valve, which prevents the formation of countercurrent flows in the circuit, in which the coolant does not move.
In both schemes, the main heating circuit is periodically disconnected, and its connection depends on the time of heating of domestic water. The initial heating time of water in the boiler must not exceed one hour. Subsequently, it will take less time to heat water, so the main loop will be off for less time, and will not affect the heating of the room.
To reduce the dependence of space heating on DHW, you can apply a mixed version. This arrangement provides two direct sources of heat. One has a permanent connection to the main heating circuit, and the second provides heat to the main and indirect heating circuits. That is the second boiler operates in one of the above-mentioned modes.
Diagram of connection of the indirect heating boiler
One pump is used to heat the living space, the second. for indirect heating of the boiler itself. Electrical connection scheme provides a system of switching modes. relay.
In the dual-pump scheme for connecting the boiler coolant flow moves in different directions through the circulation pumps. Hot water trimmer line (boiler and heating boiler) is connected in parallel to the pumps, due to the heater thermal sensor regulates the operation of pumps. A check valve is installed in the circuit after each pump so that the pumps work autonomously, independently of each other. In the presented scheme, the heating circuit is turned off, but it almost does not affect the speed of water heating in the batteries.
How to connect the unit for a boiler with two circuits
Boiler is selected by deciding on its type, location and volume relative to the capacity of the water heater. In indirect and combined types it is recommended to provide additional protection against scaling inside the coil.
Attention! It is forbidden to connect the boiler before the commissioning of the boiler by the gas service
Connection diagram
Wiring diagram depends on the type of tank:
Direct heating device
The accumulator inlet connects to the cold water inlet. The outlet spigot to the inlet of the second boiler circuit.
Cold water is sent directly to the boiler where it is heated to 60 °C by the heating element.

From the boiler the liquid flows to the boiler, losing a few degrees of temperature on the way. Passing through the second heat exchanger of the heater, the water recovers losses and goes to the DHW system through the outlet valve of the boiler.
Indirect and Combined Heaters
Have two additional spigots from the coils. They connect to the first boiler circuit. The scheme assumes that the heated coolant of the heating system will pass first through the coil storage tank, and then go to the radiators.
Due to this, the main gradient of the tap water heating is provided by the coil. Cold water is introduced directly into the storage tank, the heated liquid is diverted to the boiler DHW loop.
When the automatic system of the boiler operating with a boiler of indirect heating periodically turns on and off the burner, it is recommended to change the connection diagram of the reservoir. The boiler is not heated to the required 60 ° C when the water in the accumulator is pulsating.
Plugs of the DHW circuit of the water heater are plugged, water from the boiler is sent immediately to consumers. The speed of fluid heating depends exclusively on the capacity of the heating system, it is impossible to operate this scheme in the summer.
Indirect water heater connection diagram for a two-circuit gas boiler.
Materials and tools
Boilers internal elements are made of copper, steel or cast iron. Heating elements and coils are made of copper or steel. The steel walls of the tank are subject to corrosion, life time does not exceed 15 years. Cast-iron walls are twice as massive and more expensive, but they can last up to 90 years.
When installing the water heater, the pipes must be connected in such a way that they are separated from each other. For this you need:
- Tape measure, pencil, chalk;
- Drill set with a drill kit (for making holes for pipes, elements of wall mounting);
- adjustable wrenches and wrenches (models with ratchets are recommended);
- screwdriver set;
- pliers;
- cutters;
- joint sealant (flax, FUM tape, sanitary floss);
- sealants;
- stop valves, tees;
- fittings;
- pipes.
If there is no possibility to make detachable connections, polypropylene pipes are used, which are welded on site.
Step-by-step installation and quality control
All works shall be performed with the equipment turned off and the liquid removed from the system.
- Marking of fasteners with a pencil or chalk. Drilling of mounting holes.
- Check the load-bearing capacity of the wall. Important for mounted models. The fasteners included with the storage unit are installed on the wall, loaded with bags of cement or sand from a double supply.
If the wall material can carry a load of 100 kg, you can safely hang a boiler with a capacity of up to 50 liters.
- Placement of the tank on the wall or on the floor.
- Threading in the water supply.
- Installation of overpressure valves along the water flow.
- Installing the expansion tank.
- Fill with water and check connections for leaks. If the system filled with water does not leak after an hour of standstill, then the tightness of joints is satisfactory.
- Switching on the equipment in the network, checking operation.
How it works
On receiving a command from the boiler thermostat (water has cooled down to 45 degrees or lower), the relay switches off the heating and turns on the boiler pump.The relay on the same command from the thermostat connects in parallel to the boiler thermostat another one, which is set to 80 degrees and measures these degrees on the boiler supply.
Now the boiler, after receiving the overhead thermostat command to disperse, heats up to 80 degrees, and keeps this temperature. The boiler heats up quickly.
After heating up to 55 degrees the thermostat in the boiler breaks the circuit, the relay switches off the boiler pump and turns on the heating. The relay interrupts the circuit and switches off the overhead thermostat, the boiler is now oriented again towards the built-in thermostat with a setting of 50 degrees.
Everything is back to square one, only the boiler is heated to 55 degrees again.
The water in the heating system may have time to cool. If the boiler is cast iron, putting cold water on the cast iron can destroy it. With cast iron boilers the scheme can be applied only with an additional protection of the boiler from the cold return flow.
In general, independently make connections of the boiler to non-automated boilers that do not know how to manage the boiler, solid fuel, obsolete, etc.п. you can do with your own hands. How to connect the boiler we have just considered.
Connecting indirect water heater to single boiler schemes, options, step by step instructions
Heating in a private home, and in general the heating of water in it. something that must be equipped to live in comfortable conditions. And the more economical will be organized the process of heating water (and in this case without such equipment as BKN not do), the better will be for the cottage owner, because it will reduce costs. Connecting an indirect water heater to a single-circuit boiler. a challenge not easy, but it is solved by yourself. The main thing. to understand how to do it.
This word combination means a tank filled with water, which is equipped with a heat exchanger coil inside, connected to the boiler, which is responsible for heating the house, or to another system, inside which circulates a coolant. Water in such a unit becomes hot due to the fact that the liquid, coming directly from the boiler into the coil for heat exchange, gives its energy to the liquid in the boiler tank itself. That is, it does not heat up directly, but only absorbs heat from another source. Hence the name for this unit. indirect water heater.
Water heated in the unit can be used for a variety of household needs. And it stays warm for a long time because the system maintains the correct temperature level by itself. Install such a boiler can, by the way, not only in the cottage, but also in an apartment, hotel or other room.
The boiler itself is a metal or plastic container parallelepipedic or cylindrical. The capacity of the tank can be any and sometimes counts in thousands of liters.
For your information! Some units can have vitrified clay, enamel or other materials on the inside of the tank that help keep water in good quality and protect the metal from corrosion.
The tank with water is usually enclosed in another body, between these two structural elements is often laid thermal insulation material. It helps to keep the heat longer, and also protects the outer casing of the tank from intense heat. Water, which is responsible for heating the liquid in the boiler tank, usually circulates through a heat exchanger coil. The elements of the tank are protected against corrosion by a magnesium anode. To control the pressure in the unit, the installation of a so-called safety valve and a thermostat. The water circulates thanks to a special pump system.
So BKN is a kind of “thermos” for water in the house. It does not heat the water itself, but is able to keep the liquid heated by the coolant in a warm state.
Advantages, disadvantages, types of equipment
What is good about such a boiler? Most importantly, the water in it can be heated without unnecessary costs. That is, pay for electricity or gas in addition does not have to, unlike the same boilers direct heating, which have in their design special heating elements such as burners. Boiler KN uses a ready resource heating system in the house.
This aspect also allows you to talk about a reduced load on the power grid in the house. At the same time the performance of the boiler is high enough, it is safe and can serve for many years without complaint, because its inner part is even protected from contact with running water. Water from such a boiler comes to the consumer as soon as it is needed.
Disadvantages, of course, the equipment has. First of all, the high cost. is more expensive than a direct heated boiler. You should also understand that it takes longer to heat the water, but it also takes longer to keep it hot. And the place of such a boiler takes a lot of space, it is better to put it in a separate room. And another major disadvantage. in the summertime, in order to heat water, you will have to run the heating boiler.
For your information! There are several types of indirect heating boilers. Let’s see how they differ from each other.
Boiler and boiler interaction options
Connecting an electric boiler to a gas boiler is a very unusual solution, mainly due to the desire to reduce the price of the system installation.
The main option to improve the quality of hot water from the boiler is to connect an indirect heating boiler, with a heating pipe coil inside or layer heating

Such a system does not use electricity to heat water at all, but it is expensive to install and does not allow you to save DHW by turning off the boiler. That is why skilled craftsmen have learned to use conventional electric boilers, which are in fact a huge thermos with a built-in boiling pot and a thermostat.
Scheme #1. via three-way valve
This option of connecting the gas boiler and boiler through a three-way valve. Perhaps the simplest, most obvious and widespread. It allows you to organize a hot water supply even from a single-circuit gas boiler, saving on electricity.
The essence of the method is that the installed valve with a thermostatic regulator redirects the flow of hot water into the DHW circuit, then into the heating circuit. It is controlled by the boiler automation: as soon as the water reaches a predetermined temperature in the tank, the valve shuts off the supply of hot water to the tank. In this case almost all the time the boiler operates for heating and during the short period that the water in the boiler is replaced, the batteries have no time to cool.
However, if you have a large family or installed a huge Jacuzzi bathtub, for efficient operation of the system will require a boiler of high power. Otherwise, after using a large amount of water in the house will be noticeably cooler, and the hot water will come into the battery only after filling the boiler. Thus, the priority in such a scheme is the water supply.
When connecting the thermostat of the boiler as a servo drive three-way valve, set the temperature on it at least 10 degrees lower than that of the boiler
You can also organize bypass through the three-way valve. then under given conditions, it will direct the flow of hot water back into the boiler instead of radiators and other elements of the heating system. It adds to the system safety and ease of maintenance.
Scheme #2. through two independent pumps
Next, let’s see how to connect the boiler to a two-circuit gas boiler, using a scheme with two circulation pumps. This system is the most complex to install, but quite convenient to use. Thanks to the constant circulation of water in both circuits, hot water will flow from the tap at once, it will not need to be flushed, and heating also works continuously, regardless of the use of hot water.
One pump is needed for water movement through the heating circuit. The system is closed, you can add special additives to the liquid to prolong the life of the equipment. it will not get into the water supply. Almost all two-circuit boilers are equipped with automatic. and this pump is built into them. If your boiler does not have it, or you use a single-circuit boiler and a gas boiler, the installation of such a pump is necessary for quality heating.
The second pump provides recirculation in the hot water system. It is installed after all points of water intake, and after it the water, slightly cooled down after passing the pipeline, returns to the boiler to repeat its path until someone opens the tap.
In indirect heating boilers to connect the recirculation is a separate input, but in the electric tanks, such an input is a rarity
Recirculation supply is connected via a three-way valve at the inlet to the boiler, where the supply of cold water is usually connected, and in the case of a connection with the boiler. already heated water.
Scheme #3. through the hydraulic arrow
The hydraulic distributor is needed for adjustment of speed and pressure of water in various circuits so that the boiler and pumps could function without fail. In essence, it is a reservoir with two or more inlets and outlets, through which streams can both flow in parallel, independently, if their pressure is the same, and mix until a balance is established.
Instead of a prefabricated, factory-made hydrostring, sometimes at the boiler outlet install a section of pipe 2. 3 times the diameter, into which are cut taps with a normal diameter to the various devices. In this case, if the system is overloaded and the head of hot water, which is issued by the boiler, is not enough, water from the return, already somewhat cooled, is mixed into the line for the supply trimmer.
If, on the contrary, the boiler capacity is too high, part of the hot liquid immediately returns to the boiler, not getting into the heating circuits and water supply.
Thanks to the hydraulic distributor, the electric boiler can be connected to both single-circuit and double-circuit boiler. The separation of the circuits can be made through this system, and it will help replenish the used volume of water. It is best to allocate a separate circuit for each type of equipment: boiler and water supply, batteries, underfloor heating, etc.п.
The main disadvantage of a multi-circuit hydraulic system. it takes a lot of space and is quite difficult to design, install and debug
However, by installing such a system, you will provide long and smooth operation of the equipment throughout the house, and you can control each circuit, up to complete shutdown, separately.
Scheme #4. connection with a flow boiler
Sometimes the equipment is installed in such a way that all water heated by the boiler enters directly into the boiler, and from it the distribution is done for water supply and heating. In this case, when someone opens the tap and the pressure in the system drops, it is replenished by the cold water supply to the boiler, together with the return flow or instead of it.
This scheme is the easiest. It provides quality DHW: the water will always be hot, immediately and at the same temperature.
The positive points of this solution may be a small amount of additional equipment, as well as undemanding parameters for the boiler.
If an electric boiler is installed with a gas boiler as a flow-through, there is no point in overpaying for either the volume or additional functions: only the quality of the tank is important
Connecting the boiler according to this scheme, do not forget to set the relay to a low temperature, or even to a minimum, so that the heating element does not try to heat water more than the boiler will do.
The subtleties of installing system components
After determining how to connect the gas boiler and electric boiler, you need to think carefully and make a scheme of bundling, and then proceed to the installation.
Step #1. connecting the gas boiler
This step should be entrusted to professionals: as well as any other gas equipment, the gas boiler has the right to connect only professionals certified by the gas service. This is due to the fact that even minor errors in the installation and configuration, are fraught with serious consequences.
In a variety of outputs two-circuit boiler can easily get confused, and if you run the wrong boiler, the expensive equipment can break down
If a leak in the water or sewerage system you are threatened by a puddle, at most. a couple of inches of water on the floor, then an error in connecting the gas boiler threatens a fire, explosion or poisoning by combustion products.
Schemes of installation of a two-circuit gas boiler we reviewed in this material.
Step #2. Boiler Installation
An electric boiler that works in conjunction with a gas boiler is connected in the same way as a standard. The only difference. it is not served cold water from the water supply, but hot water from the boiler.
Planning the scheme of hot water supply with a boiler and a boiler, be sure to adjust the thermoregulator of the latter to a lower temperature than in the boiler
Step-by-step instructions for installing the boiler are discussed below:
Boiler and boiler installation is the basic, easiest and most important part of the work, but this is only the beginning. For their effective interaction it is necessary to make the strapping according to a pre-selected scheme. Let’s talk about the elements of such schemes below.
Step #3. connections and additional equipment
The first thing you should start with any system associated with water. the installation of a filter for its purification.
Installing a mechanical water filter will prevent small solids from getting into the heating and water system and extend the life of the equipment
Choosing a filter, keep in mind that the better it will purify the water, the longer will last and the boiler, and the boiler, and all other equipment. Otherwise, small particles from the water settle on the walls of the coil and the tank, form a scale on the boiler heating element, contribute to the destruction of the tank and lead to rapid failure of all parts of the system. from the boiler to the faucet in the kitchen.
However, to choose the most expensive filter that cleans tap water to drinking water, too, is not worth it. it is too expensive and irrational. Filtering system with 2. 3 levels of mechanical purification of varying degrees, from coarse to fine, will be enough.
The filter is installed at the beginning of the chain, before connecting the water supply to the boiler. Be careful with the direction of flow. it is usually indicated by arrows on the body.
During operation, do not forget to regularly change the filter cartridges, otherwise they will cease to perform their function and may adversely affect the water pressure.
The second obvious and necessary equipment. ball valves. You need a lot of them, they are placed at each connection: before the filter, on the inlet and outlet of the boiler, on both boiler connection pipes, on each outlet of the hydraulic arrow, before each water tap.
This number of taps ensures the safety and comfort of operation. At some point, each unit of the system will require preventive maintenance, and possibly even replacement, and the ability to disconnect only it is very important.
Expansion tanks are installed to compensate for the differences in pressure in the water supply or heating circuit due to changes in water temperature. for safety
At the organization of DHW through a boiler, the expansion tank is usually not required: in case of critical rise in pressure the boiler safety valve will work. But if the heating circuit is derived separately, such protection would not be superfluous.
In addition to these devices, as well as the hydraulic pointer-check valve, which was discussed above, the pipelines are installed check valves. preventing the flow from reversing even when the pump is switched off, safety and three-way valves, if necessary a pressure reducing valve to reduce the pressure.
How to connect an indirect water heater to a single-circuit boiler
The best position is when the bottom of the hot water tank above the heating boiler and radiators. With recirculation of the coolant In the presence of a water towel dryer in the system requires a constant circulation of water through it. For the system to function properly you need an accurate calculation of the pump for indirect heating boiler. There are several ways. The complete set of small volume tanks no more than 15 liters is usually represented by one heating element with a capacity of 1.0 kW. Such a heating element is in direct contact with water, resulting in scale formation on it, which must be removed. Installation methods and shapes of boilers Boilers can be wall and floor mounted, horizontal or vertical models. So the water takes a long time to heat. The hot walls of the coil transfer heat to the cold water, which at the outlet already has a temperature suitable for taking a shower or washing dishes. Control the pressure. At this point the installation can be considered complete. The speed of heating is fully dependent on the capacity of the unit and its volume. Indirect heating boiler
Rarely connected to free-standing boilers of similar volume. The water temperature for the boiler via a thermostatic head with an integrated sensor can be set at a temperature no higher than the temperature of the heat carrier. There are several basic ways of tying the boiler, which are: with two circulating pumps Both pumps are designed for parallel operation. In normal mode, the top layer of water in the tank is used first, and it is hotter. We have already mentioned the three-way valve. The heated water is spent as required for the household needs. General requirements To ensure that the strapping system of a single-circuit boiler with a boiler works properly, without interruptions and emergencies, you must maintain the following requirements: At the outlet of the boiler set the expansion tank volume of not less than 10 percent of the boiler. Binding boiler with an indirect heating boiler is as follows: Near the circulation pump is cut in the three-way valve. The inner coating of the tank In cheap boilers, the inner coating of the tank is made of enamel or vitrified clay.
Stainless Steel. Many single-circuit gas boilers have a summer mode, which will not work for the heating system, and provide heating to the boiler indirect heating. Both have horizontal and vertical models. In this case, the boiler electronics knows the temperature of the water in the DHW system, and it decides where to direct its power: to heat water in the BCH or for heating.
The boiler is designed so that when water flows out, it fills a new portion of water, and the process continues. The water in the tank can be heated by connected solar systems for heating or heat pumps. Remember about the proper setting of the thermostat!
How to avoid these defects? They differ in their complexity, so you have to choose the best option. That is, in this case, it is desirable to install wall-mounted models. Ideally, the bottom of the indirect water heater is above the boiler and radiators. Boiler indirect heating device, principle of operation and connection diagram
Connecting an indirect water heater to a single-circuit boiler. scheme
It is necessary according to the scheme to find terminals in the boiler for the boiler sensor and connect the ends of the wire in them.
Conventional indirect heating boilers work mainly with automated boilers.
Connecting the boiler to the boiler using a three-way valve This connection scheme is ideal for gas boilers, equipped with a circulating pump and automatics. Preference is given to wall-mounted models, which can be hung at a height of 1 m above the floor.
The best position is when the bottom of the hot water tank is above the heating boiler and radiators. How to connect an indirect water heater to the heating system correctly? Less often connected to free-standing boilers of similar volume.
The design of the indirect heating boiler
Indirect heating These water heaters do not produce thermal energy on their own. If you need to create a wiring diagram for solid fuel boilers that run on wood, we recommend choosing the option shown in the picture below. Some manufacturers intentionally produce equipment with standard size connectors and fittings.
In this scheme there is no three-way valve, the circuit is connected through conventional tees. With this detail, the unit serves much longer. Working at very high temperatures can cause premature damage to the inner surface of the tank. Types of two-circuit gas boilers with a built-in boiler Do you need them Boilers are used in conjunction with single and double circuit gas boilers. Circulation pump is common here, it drives the coolant through the heating circuit and the water heater.
How to connect the boiler (water heater) of indirect heating
Connection scheme of the indirect water heater in the gravity system When implementing this scheme, the circuit that goes to the water heater, make a pipe with a diameter 1 step larger than the heating. They have a coil and built-in heating element.
This method of strapping is useful for those who use the boiler in a constant mode 2: Variant with two circulating pumps If the boiler is used rarely, such as seasonally or on weekends, or there was a need for water, the temperature of which is lower than in the heating system, use a scheme with two circulating pumps. Works heating system of the apartment or house, and as if a side effect, the water is heated in the boiler. The boiler connected to the heating equipment and electric heaters This method is possible only if there is a separate boiler equipment, which is able to work from natural heating sources in the form of liquefied gas, coal or wood all year round. The hot water circuit also has a higher priority over the heating circuit, but it is achieved only by setting the algorithm. Performing the strapping requires the prior competent performance of thermal calculations. Ufa. Indirect water heater connection diagram.
Pipe material for the piping of the BKN
On the regulator of the thermal head the desired temperature of water heating is set no higher than the temperature of the boiler supply. Also in the data sheets instructions for use. Heating temperature and pressure on the pipe determines what material is preferable to use when making strapping: Cold water. can be installed conventional polypropylene pipe. The flow of coolant is regulated by a thermostat that opens and closes depending on the temperature of the water in the tank. Binding BCH should solve several important problems: to ensure uninterrupted circulation of coolant from the boiler to the water heater, to prevent hydraulic and thermal shock, to maintain the set temperature of water heating in automatic mode. What is heating with priority Before you install an indirect heating boiler in the DHW system, you need to choose the principle of its connection: with or without priority. The point is that the fluid is constantly circulating through the loop and is cooled, so the boiler spends a lot more resources on constant heating. In addition, the temperature drop is enhanced by mixing the different layers of liquid. If more intense heating is needed, this can occur if the boiler normally operates in a low-temperature mode. It is better to choose a model with a built-in heating element. The material is suitable for soldering the entire DHW system. If the customer shuts off the boiler, make sure that when you turn off the boiler turns off all systems and equipment. Also look for an electrical connection diagram of the boiler to the boiler. Connecting the indirect heating boiler in this case is shown in the diagram below. In addition to the installation and connection of the BKN will require regular maintenance.
The nuances of piping arrangement It is easier to do wiring and piping, if the boiler KN installed together with the boiler, pumps and other equipment involved in the assembly of the DHW system. Let’s take the simplest case, when there is already an automatic system in the water heater. We can say from experience that the dry heating element is better to avoid. The first scheme of the heating system with an indirect heating boiler directs the entire volume of the coolant to heat the tank, due to which very rapid water heating is provided.
That is the steel pipes are overgrown. In this case the boiler heats up faster, but then the heating stops completely and the temperature in the radiators can drop significantly with prolonged idle time. If you turn off the heaters for a minute, the temperature in the rooms for such a short period of time is unlikely to decrease, but the heated water will be enough. Connecting an indirect heating boiler with recirculation The second option is to use models that do not have an inlet to connect the recirculation circuit, but connect it using tees. That is, during the preparation of DHW heating circuit is turned off. Equipment for a boiler room. What are the elements that make up a modern boiler room?
Fittings for piping OCB
This ensures the priority. If the tank is not equipped with a safety group, it is installed separately, with the arrangement of piping.
Because some sophisticated boilers have protection against disabling the heating caused by long heating of DHW. The first one is installed on the supply pipe directly before the BKN, the second one. on the heating circuit.
Therefore, when choosing. you need to decide what scheme of connecting the boiler is used, how many energy sources will be involved and what. Practice showed that at a high flow rate the water may not be heated to the required 60 degrees. To reduce the time of water heating and for slower cooling of the tank, it is better to choose models with thermal insulation.
Because there are boilers with the function of switching off the heating on the room thermostat, and the DHW function is still working. No need to think that heating water will begin to lower the temperature in the house. the water is heated quickly, your home will not have time to cool down. As noted above, a great option is the solid fuel boilers, working on all available fuels.
Connection with a three-way valve
You will agree that this connection is not safe, even if you dilute the water with a mixer. Conclusion Binding single-circuit boiler with a boiler of indirect heating is performed according to different schemes, each of which allows to solve a certain number of problems.
Here we use the priority of the indirect heating boiler. If strapping is done correctly, you will not need a quick repair, but if you have problems with the equipment, we recommend contacting experts. When all the technical points are settled, it remains only to pick up the volume. On the other hand high temperatures increase the scale in heat exchangers and pipes, which in the future may lead to loss of capacity and failure of the boiler due to overheating. But you have to somehow put up with the lack of ability to adjust the temperature to your liking.
If you want you can do without the pump. for normal delivery of the coolant in the water heater pipes feeding it should have a larger diameter compared to the pipes of the heating circuit. In normal operation, the hottest water is at the top, from where it is fed into the DHW circuit. That is, by increasing the temperature, you increase the accumulation of hot water in the boiler at the same capacity. If you have a temperature of 90 degrees in the boiler, you will already be able to use the shower for over 60 minutes.
Imagine that you have hung on a wall made of gas block floor BCH for liters. This scheme with the same efficiency can be used as for electric, gas or solid fuel heat generator. That is, at a low temperature there is no afterburning gas. This method of connecting is useful for those who use the boiler in the permanent mode Connection with two circulation pumps If the boiler is used rarely, for example, seasonally or on weekends, or if you need water with a lower temperature than in the heating system, you can use a scheme with two circulation pumps. And the boiler is an auxiliary element when you need to heat quickly, or when the sun’s energy is not enough. Heating in a townhouse. Inexpensive.