Tool you will need:
Based on materials:
I want to briefly tell you why I did this. In the photo above you see an old electric boiler made from a gas cylinder, it took up a lot of space, was located incorrectly, due to the large amount of water in it and the presence of only one 1.5 kW heating element in winter, it simply did not cope with its task. The last battery was barely warm. We heat ourselves with electricity due to the fact that the apartment building has not yet been gasified. So I decided to remake it with the addition of another heating element.
As a heat exchanger, I took a piece of pipe, in the designated places, so that the outlets coincided with the outlets on the battery, and burned holes by welding. I don't have an autogen.
The hole must be ground with a grinder and a grinding disc to remove slag and metal buildup.
The photo below shows the prepared bends; they need to be welded into the holes made.
I welded two 1.25-inch bends at the top and bottom for the heating supply and return.
To make the bottom, I used a metal plate, which I then welded and during the work, I cut off the excess with a large grinder and sanded it with a small one.
Welded plate.
One of the prepared half-inch surges was brewed at the very bottom of the boiler, in case it was necessary to drain the water from the entire system.
The second one was welded for an additional heating element of 0.9 square meters. The third is for the expansion tank, which also needs to be installed, since water tends to boil away.
The photo shows welded 2.3 bends.
How to install a heating element and what it is
The heating element, which I will mount at the bottom of the boiler, then you will understand how to do this.
Since I don’t have a half-inch drill and couldn’t find it anywhere I looked, I decided to use welding.
At the very bottom of the heat exchanger, I welded two holes for the lower heating element.
Then I sanded everything down to remove metal and slag deposits.
We insert the heating element into the heat exchanger, place rubber seals and large washers, and tighten everything thoroughly with nuts.
The main thing here is not to overdo it, otherwise you can break the heating element. I installed the second heating element at the top, it is about 50 cm in length with a thermostat in the photo below you will see it.
The hardest part of the job is over, all I have to do is put everything in place and start the boiler.
Before installation, fum tape must be wound onto the threaded connections. You need to wind it about 10 turns.
To drain the water, we screw on a half-inch tap or a metal plug, whoever has what, I screwed on the plug, and this is what happened.
At the top of the electric boiler you see a heating element with a thermostat.
Now we have everything installed and are moving on to the next stage.
After the above work, you need to connect the lower heating element to electricity. We insulate everything well; for example, I stuck the wire into a small thermal tube and wrapped it with electrical tape.
On suitable wires, it is necessary to install 16 ampere circuit breakers and make grounding, I did all this. The upper heating element plugs directly into the outlet, so there was no need to do anything fancy.
I poured as much water into the system as needed and turned on both heating elements. The result exceeded expectations.
A few hours later, the upper heating element had to be turned off due to the unbearable heat in the apartment. The photo shows how I measure temperature with a multimeter. 76 degrees suited me just fine.
Even at minus 10 degrees outside, only the lower heating element works. The apartment is 22-24 degrees, very warm. I painted everything, and this is what happened.
If you decide to do something like that, good luck with your work.
Electrical systems are the safest equipment, thanks to which you can create a comfortable temperature in the room during the winter. The efficiency of an electric heating boiler is quite high, especially since in order for it to operate normally and stably for a long time, you do not have to waste free space for laying flammable material.
Electric boilers completely lack a mechanical component, making their use much easier and also reducing the likelihood of a malfunction or serious breakdown.
The design of an electric boiler implies temperature regulation. Due to this, the system can respond in a timely manner to any changes in temperature in the environment. The boiler either increases or decreases the heating temperature if necessary.
Many boilers are economical; for example, to heat 30 cubic meters of space you need to spend only 4 kW per day. The use of such boilers makes it possible to heat rooms of much larger volumes than with other types of boilers.
During operation, the boiler does not emit any harmful or toxic substances such as carbon dioxide or carbon dioxide. In this regard, they can be installed directly in residential premises and used to heat bedrooms and children's rooms. Another advantage is that during installation you will not have to obtain any permissions from the relevant authorities.
Electric boilers can either be used as an additional source of heating or the structure can be made the center of the heating system. This boiler is powered from an ordinary electrical network with a voltage of 220 V. The average weight of the boiler is 22 kg, its dimensions are also not too large, but it is capable of heating a volume of air up to 400 cubic meters.
device 
diagram of a heating element electric boiler For work you will have to use some materials and:
You can make the following types of boilers yourself:
Manufacturing instructions:
A separate issue is connecting the structure to the electrical network. If you do not have the skills for such work, then it is better to contact an electrician. Then they are engaged in the installation of a less powerful heating element, which should have. It is attached to the upper pipe.
connection diagram The most difficult thing is to connect the structure to the electrical network. Since we have to deal with heating devices, we will have to install the input on 3 phases.
A number of systems will need to be installed directly in the electrical panel itself:
It is mandatory to make a grounding loop. To do this, you need to take a metal pin or reinforcement, the diameter of which should be approximately 15-20 mm, and attach a metal bolt to it. This structure is placed under the floor of a residential building and a wire coming from the electrical panel is passed to it.
There are 2 main types:
At the same time, all the others are just modifications of one of these types. An electrode boiler is often also called an ion boiler, since it converts electrical energy into heat.
The design takes up a minimum amount of space, and it is fixed directly to the pipe; it does not even have to be attached to the wall. Just in case, it is placed on 2 screws, but this is not necessary.
Outwardly, it looks like a small piece of pipe, the length of which is about 40 cm. At the end of the heater there is a metal rod, and on the opposite side the heater is welded or there is a special pipe in it, due to which the coolant is transferred throughout the entire system.
The design provides for the presence of 2 pipes into which pipes for return and supply are inserted:
principle of operation This boiler has the following operating principle: the cathode (positively charged electrode) and anode (negatively charged electrode) are placed in the coolant. When energized, they trigger the movement of ions. Their polarity changes from time to time, in particular, one charged ion will change its charge from one to another approximately 50 times per second.
This ultimately leads to friction in the liquid due to this movement of ions, which causes an increase in temperature.
This technology leads to some disadvantages:
Induction boilers operating on electric current heat the coolant using a magnetic field that arises from the electric current.
This whole design is quite simple and includes the following elements:
The key difference from the electrode design is that in induction boilers the liquid is completely isolated from the conductive elements, so it will not be energized.
The coil winding, made of copper wire, is connected to the network through a special control system. Due to this, a magnetic field appears in the coil. It will heat up the pipe, which acts as a core, and it will already give off some heat to the water. At the same time, the body of the heating boiler will continue to remain cold, since its design contains a layer of insulation.
It should also be said that the core is not made straight, but has a curved shape, sometimes in the form of a spiral, so that the coolant passes through it much longer. The service life of such a boiler is at least 25 years. After this time, the pipe, which is the core, will rust.
Preparing an electric boiler for startup means that it must be completely checked all connections, the electrical network, and the filling of the system with water. If there are pinched or torn wires in the wiring, they will need to be replaced and carefully insulated. It is prohibited to do otherwise, since in a three-phase network there is voltage with a decent current strength, and the replaced section can break through.
Preparation also involves cleaning the structure from dust and dirt. You should also take care to prevent voltage surges both during the first start-up and during further operation. To prevent this from happening, install a residual current device.
Start:
To create an efficient heating system, you need a modern heating boiler. This can be a device that runs on electricity, solid fuel, or gas. Today there are also a large number of combined models. However, having a sufficient level of knowledge, the necessary materials and a diagram, you can easily create a homemade electric boiler for heating.
In essence, the boiler is a metal reservoir in which a thermal electric heating element (TEH) is located. The most common are models with a power of 6 kW - this is quite enough to heat a small, well-insulated house or apartment. However, it is most rational to use such a boiler as an auxiliary one in the presence of a main boiler operating on solid or liquid fuel. If the system does not provide for a boiler of a different type, you can use two or more electric boilers - this will increase the heated area.
A modern homemade electric heating boiler, even one created with your own hands, can perfectly maintain the set temperature level in the room automatically.
To do this, you need to equip it with several sensors and a simple automatic unit. Using automation is an excellent way to reduce energy costs, since the boiler will be able to maintain the temperature in the room at a programmatic level - thus, the coolant will not be heated excessively.
Manual operating mode. Toggle switch T must be turned off. Next, click Start. The system checks the room temperature. If it is below the adjustable value (closed TP contacts), the magnetic switch is automatically triggered. It blocks (temporarily) the Start button and starts the heating element. The coolant gradually heats up, resulting in an increase in the temperature in the room. As soon as the sensor shows that the temperature is within the established limits, the contacts of the TP and the magnetic switch of the heating element are opened. The heating element is switched off and the Start button is unlocked.
Auto mode.Toggle switch T should be turned on. This will allow you to maintain a constant temperature in the room, limited by the activation zone of the TP contacts. If the air temperature drops below the specified limit, the boiler automatically turns on. Thus, the coolant heats up, which increases the temperature in the room. When the set temperature is reached, the circuit breaks, and the electric heating boiler comes into inactivity with its own hands. If necessary, the activation is repeated.
Even if the electric boiler for heating with your own hands is auxiliary, it must still be located next to the main boiler. In this case, the combination of boilers is carried out using bends.
The electrical control board must be installed on a special panel insulated from the coolant. At the same time, by creating the boiler yourself, you also determine the components selected for the board.
To comply with all installation rules, which, in turn, ensures the continued safety of the equipment in use, it is advisable to invite an electrician.
It is especially important to do this, given that even individual “kulibins” cannot always properly ground an electrical appliance. In addition, it is important to regularly check the safety of the system - invite a specialist who can take the necessary measurements and issue an appropriate report on the condition of the operating heating element.
It should be taken into account that individual sensors, in particular the room air temperature sensor (TR-OMb-OZ), must be installed in a heated room. If there are several such rooms, then the sensor is installed in the one that, in your opinion, has an average level of heating. It should be noted that the proposed heating boiler circuit is designed specifically for a sensor of this type - and if you replace it, some of the elements of the electronic control system must also be replaced.
Homemade electric heating boilers of this type will easily serve you for more than 10 years. However, it is important to understand that in order to achieve such a service life, it is necessary to follow certain installation rules, and, of course, operating rules. Here are the most important:
Do-it-yourself electric heating boilers - drawings:
Heating using electricity is not very profitable, but it provides a lot of advantages: comfortable operation, relatively low price of equipment, safety. This article is devoted to the installation and connection of an electric boiler in a private house. After studying our detailed guide, any skilled homeowner can easily install an electric boiler with their own hands.
The choice of a heater operating in conjunction with a water heating system is made based on power and operating principle (the cost of the equipment depends on the latter). Electric boilers have no problems with functionality - any model is equipped with an automation unit. If desired, various peripheral devices can be connected to it - weather sensors, room or overhead thermostats and GSM modules for control from a mobile phone or via the Internet.
After completing the work, the craftsmen make a note in the technical data sheet of the product.Important note. Some manufacturers, for example, Galan, Protherm or Evan, require in the operating instructions that the installation and connection of the electric boiler to the network be carried out by specially trained personnel. Self-connection will result in a waiver of warranty obligations.
Before choosing and purchasing a heating device, check how much electrical power is allocated to your home by the management company. It may happen that it is not enough for individual electric heating. Point two: a single-phase 220-volt network is capable of powering boilers that consume up to 12 kW/h inclusive. More powerful water heaters are connected to a three-phase 380 V power supply.
This indicator is calculated using the standard formula: calculate the heated area of a country house or cottage, then multiply the quadrature by 0.1 kW. Obtain the thermal energy demand that the electric boiler must cover.
Consider a number of nuances:
Example. A small house of 100 m² on average requires 100 x 0.1 = 10 kW of heat. The power of the electric heating installation is 10 x 1.2 (20%) = 12 kW. We need to heat water for household needs - multiply by a factor of 1.5 and get 15 kW.
To obtain more accurate results, we suggest studying the methodology
Electric mini-boiler room with tubular heaters (TEN), fully equipped Valuable advice. Do not listen to the tales of salesmen praising the efficiency of certain electric boilers. They like to use the expressions “energy-saving”, “eternal”, “economical” and so on. Remember: all types of heaters equally effectively convert electrical energy into heat with an efficiency of 98-99%.
The first place in the user rating is occupied by heating element heaters. The only weak point - the heating element itself - has long been protected with ceramics, and in addition it is easy to replace. Modern models of heat generators are wall-mounted mini-boiler rooms with a built-in expansion tank and circulation pump. There are simpler versions that include only heaters and an automation unit.
The cheapest and most reliable option is an electrode boiler with a control cabinet, shown in the photo. Its disadvantages:
Induction electric boilers for heating a private home are quite expensive, and there are questions about the reliability of the devices. There are known cases of phase burnout inside the coil, the power of the heat generator dropped by a third. Fixing the breakdown is very problematic.
An induction heater heats water with a metal core located in the vortex field of the coil Electric water heating boilers of all types are designed for wall mounting and are equipped with mounting brackets or clamps. There is no point in explaining the marking and driving of dowels - every homeowner knows how this is done.
For reference. In a floor-standing version, universal electric wood-burning and coal-fired boilers are sold, described in.
Another question is how to choose the right room and specific location for installing the electric boiler. On the one hand, regulatory documents do not prohibit installing a heat generator in any room. On the other hand, there are rules for the use of electrical installations (PUE), which impose restrictions on the placement of high-power thermal power devices.
The wall version can be hung even in the corridor, but all communications will have to be pulled there 
Recommended clearances to the Proterm Skat boiler unit specified in the instructions
Important! Be sure to connect the body of the electric boiler to the grounding bus. If there is none, make a grounding loop outside and lay it in the boiler room. Find detailed instructions below.
As a rule, an electric heat generator acts as a backup device for the main solid fuel or gas boiler. This means that heat generators and auxiliary equipment need to be configured correctly to ensure a minimum of pipeline crossings. Think and draw a diagram in advance.
Wall-mounted mini-boiler rooms with a built-in expansion tank, pump and safety group are operated in closed heating systems with forced circulation, operating under pressure. The connection is extremely simple and does not require display in the form of a diagram: the supply and return pipelines are connected to the corresponding pipes of the electric boiler.
Note. The automation of such heat generators monitors the pressure in the heating network using a sensor. If the coolant pressure is below the set threshold (usually 1 Bar), the device will not turn on.
The safety group protects the system from overpressure and releases excess air The first diagram illustrates the connection of an electrode or induction boiler to a closed-type heating network with. A shut-off ball valve is installed on the direct outlet section of the supply pipe, followed by a shut-off ball valve. The pump and filter - mud collector are installed with equal success on the supply or return.
Note. This and subsequent diagrams do not conventionally show the make-up pipeline. It should be inserted into the heating return line.
The heating element version of the electric boiler, which is not equipped with an expansion tank, safety group and pump, is connected in a similar way. If it is necessary to organize a connection to an open-type gravity (gravity) heating system, then the pipelines are laid with a slope of 3 mm per linear meter, and the circulation pump is mounted on.
The ability to work by gravity does not give the circuit a big advantage - without electricity, the boiler will still turn off An open expansion tank is located at the top point of the network. To ensure stable gravity flow, the manufacturer of electrode boilers “Galan” recommends maintaining the height of the vertical section between the heater and the tank at 2 meters. Accordingly, the tank is placed in the attic of a private house.
Comment. Installing a wall-mounted electric boiler, whose pipes face downwards, will not allow the coolant to circulate naturally due to convection. An example is units of the Evan or Proterm brand. Heaters with side and top fittings - “Galan”, “VIN” and the like - are suitable for gravity systems.
To connect an electric heat generator together with a solid fuel boiler, use a circuit with two check valves, a surface-mounted thermostat and a room temperature controller. This connection option provides automatic “pickup” of the cooling system by the electric boiler after the firewood load burns out.
Check valves prevent the coolant from flowing into the adjacent circuit and moving in the opposite direction The algorithm of the circuit looks like this:
Note. The piping method is also suitable for other types of boilers - gas, diesel, and so on. Please note one nuance: the electric heater is used here as a backup heat source.
Connecting to a buffer tank, shown in the next diagram, also allows you to combine several heat sources and accumulate a sufficient amount of energy in the tank. The heat accumulator is very useful in a situation where the electric heater operates at night, taking advantage of a cheap tariff. During the day, the device is inactive, and the building is heated with heat from a buffer tank.
In this scheme, you can organize the operation of the electric heater according to a schedule using a timer The task of the mixing unit c is to supply the radiators with water at the required temperature, because the heat accumulator is “charged” to 80-90 °C. If the rooms have underfloor heating water circuits, a second mixing unit is made for them, preparing the coolant at a temperature of 35-45 °C (maximum - 50 °C).
There are two ways to get hot water from an electric boiler for household needs:
In the first case, the device is connected according to the standard diagram shown in the picture. There are a minimum of difficulties here; the main thing is to correctly install the shut-off valves.
For ease of cleaning, the mud pans should be in a horizontal position. The connection with the indirect heating boiler is carried out through a three-way switching type solenoid valve. At the command of the thermostat built into the storage tank, the element switches the coolant flow to heat water for hot water supply or heating radiators. Loading the boiler is a priority: until the tank warms up to the set temperature, the radiator network will not receive heat.
In the case of an induction or electrode unit, the immersion thermostat is connected to the contacts of the thermal relay Important point. For this reason, the selection of heat generator power plays an important role. If it is not enough, the heating of the tank will take a long time, and the room air will have time to cool down. For more information about how the system works, watch the training video.
Although the plot talks about connecting a storage water heater to a wall-mounted gas boiler, the essence does not change - the electric heater is connected in the same way.
The power supply circuits are the same for all electric boilers, the only difference is the number of phases. Devices with a power of up to 12 kW are connected to a single-phase 220 V network, more than 12 kW - to a three-phase (380 V). What you will need for installation:
A VVG cable of any type is used as a power line; the number of cores depends on the number of phases - 3 or 5. Select the cross-section of the current-carrying part according to the power of the heat generator, usually this parameter is indicated in the product’s operating instructions. To simplify the task, we present the data for different boilers in the form of a table.
The rating of the differential circuit breaker also depends on the power consumption of the heater; the operating current is 30 mA. For example, to protect the power line of a 3 kW (220 volt) unit, you will need a device rated at 16 A; for a power of 16 kW (380 V), you need a 32 A difavtomat. The exact ratings are indicated in the product data sheet.
To independently connect a wall-mounted electric mini-boiler room, you need to remove the front panel, run the power cable inside and connect the wires of the corresponding colors to the terminal block contacts. As a rule, the neutral wire is indicated in blue, grounding in yellow-green. The control box of the induction and electrode boiler is connected in the same way.
Electrical connections between the control cabinet and the heating block of an electrode or induction boiler are made according to the individual diagram presented in the instructions. As an example, we give a connection diagram for the popular Galan electric boiler.
Automation diagram for single-phase 220 V network The temperature of the coolant here is monitored by overhead sensors installed on the metal sections of the supply and return pipelines. The devices are connected in series with the contacts of the thermal relay that controls the magnetic starter. When the upper temperature threshold is reached, the circuit breaks and the starter turns off the heating. How to make grounding
Laying a grounding loop near a private house is a simple matter and very useful from the point of view of electrical safety. For installation, find 3 steel rods Ø16 mm 2 m long and a strip with a cross-section of 40 x 5 mm.
Stepping 3 m away from the wall of the building, arrange grounding according to the step-by-step instructions:
Upon completion, treat the welding seams and the above-ground section of the strip with bitumen and bury the hole. For more information about the grounding device for an electric boiler and home appliances, watch the video:
In order to avoid making stupid mistakes during the installation and wiring process, before installing an electric boiler, you should talk to a specialist in this field. The operation is not as simple as it might seem. Pay special attention to the electrical part, since high voltage is a source of increased danger.
The heart of the heating system of a country house is the heating boiler. The most economical option is to install a gas unit, which will provide a constant temperature and optimal heat costs. In the absence of main gas, the problem is solved by installing a solid fuel heating structure or installing a unit that uses electricity. Of course, the latter option cannot be called cheap given the constant rise in prices for energy supplied by wire. If there is no alternative or you need a backup heat source, then this option is irreplaceable. The retail chain offers several types of electric heating boilers, so with money in your pocket it’s easy to choose the right option. For those who are not looking for easy ways and want to save money, we will tell you about the features of making an electric boiler with your own hands. At the same time, costs are reduced to a minimum.
Homemade electric boiler
Electric heating boilers have a simple design, which makes them highly reliable and affordable. At the heart of any unit is a heat exchanger, which consists of a container and a heating device. Depending on the method of operation of the latter, all electric boilers are divided into several types:
In addition, each heating installation is equipped with pipes for supplying and discharging coolant, as well as a thermostat that maintains the temperature in the boiler at a given level. The movement of the working fluid in the heating system can be carried out either by gravity or by force - this depends on the type of equipment. If there is a need for a circulation pump, then it is installed at the inlet of the return line.
Electric heating boiler design
The safety of the electric heating unit is ensured by a safety valve. This automatic device relieves excess pressure in case of uncontrolled growth due to boiling of the coolant. Similar problems occur when the control unit or thermostat responsible for temperature stability breaks down. Protection against electric shock is provided by a grounding loop and a residual current device (RCD).
If it is necessary to reduce heat losses (for example, if the boiler is installed in an unheated room), then the heat exchanger is protected with a layer of insulation and installed in a protective casing.
The operating principle of the installation depends on the method of heating the coolant, so we will consider the features of boilers of all types.
Boilers that use tubular heating elements are most widely used due to their simple and inexpensive design. The heating elements that ensure their functionality are installed directly into the heat exchanger tank. Heating occurs due to the high resistance of the heater coil. When current passes, it heats up to a high temperature. Thermal energy is transferred to the liquid, which washes the surface of the working element. Thanks to the constant circulation of the coolant, overheating of the heating element is eliminated and uninterrupted operation of the system is ensured. To maintain the temperature at the same level, the boiler design includes a thermostat that breaks the electrical circuit when the set parameters are exceeded. The device is restarted automatically when the temperature drops to a minimum level. The range of parameters is set by the user and selected taking into account personal preferences.
Schematic diagram of an electric boiler with heating elements
The described heating unit is an ideal design for manufacturing at home. All you need is a suitable container and tubular electric heaters. Nevertheless, such a boiler cannot be considered ideal. The disadvantages of this solution include low efficiency - less than 80% and a strong dependence on the quality of the coolant. The fact is that salts dissolved in water form scale on the heater tubes. A decrease in thermal conductivity leads to overheating and premature failure of heating elements. Experts say that limescale deposits just 2 mm thick reduce the performance of the device by more than 25%. Despite this, the advantages of simplicity and low cost make the electric boiler with tubular electric heaters the most popular design among home craftsmen.
Unlike heating elements, boilers using the physical phenomenon of electrical induction have almost one hundred percent efficiency and impressive durability. The service life of the units reaches 30 years, and in parallel with the main task, they can serve as a boiler for the hot water supply system. Thanks to energy conversion with virtually no losses, induction heating systems are very economical and have maximum energy efficiency. What's the catch, you ask? Why didn’t this option become the most popular among “do-it-yourselfers”? It's all about the complexity of the design and the need to use electronic voltage converters.
Schematic diagram of an induction heating system
Structurally, an induction boiler consists of an electric coil - an inductor mounted on a metal core. The latter is a labyrinth of pipes through which the coolant of the heating system circulates. By and large, such a circuit is nothing more than a transformer with a short-circuited secondary winding. When supply voltage is applied to the inductor, an electromagnetic field appears around it, which generates eddy currents in the body of the conductor (section of the heating system pipeline). They heat up the metal of the hollow core, inside which water or antifreeze circulates. Heat transfer occurs with virtually no loss, and the contact area is several times higher than when using a heating element. This, as well as the possibility of heating the steel conductor to a higher temperature, helps to increase the heating rate and reduce the thermal inertia of the heating system. Just as in the case of tubular electric heaters, the constant movement of the liquid prevents overheating of the installation and contributes to long-term operation of the unit. We also note the fact that operating currents create vibration of the core walls, which prevents the formation of scale.
The principle of operation of an electrode boiler resembles the operation of the well-known design of an “army” boiler, consisting of two blades, the gap between which is determined by the thickness of the matches laid. Thanks to the salts dissolved in water, the liquid is a good conductor. This is what is used in the popular scheme. A direct electric current applied to contacts immersed in water promotes the movement of charged particles from one electrode to another. If we apply alternating current from our network to the described circuit, then the charged particles will change the direction of movement with a frequency of 50 Hz (that is, 50 times per second). According to Ohm's law, a decrease in resistance at a constant voltage entails an increase in current, so it is important to maintain a high salt content in the liquid.
Operating principle of an electrode boiler
Heating of the coolant is carried out due to the constant movement of ions from one electrode to another. Moreover, even the most saturated water is significantly inferior in electrical conductivity to metals such as steel or copper. Thanks to its increased resistance, heating occurs, the power of which can be calculated using the formula:
Electrode boiler design
Structurally, the electrode boiler is a body in the form of a piece of metal pipe and a round electrode located inside, insulated with a fluoroplastic or fiberglass sleeve. Phase voltage is supplied to the internal contact, and zero is connected to the unit body. A prerequisite is the presence of a high-quality grounding circuit, which is also connected to the ground of the boiler. When operating the installation, a special coolant or baking soda solution is used as an electrolyte. In this case, it is important to maintain the exact alkali content, since the current strength in the circuit, and therefore the power of the installation, depends on its amount. A thermostat is also used to regulate the temperature in a system with an electrode boiler, and the safety of the unit is ensured by installing a safety valve, a circuit breaker and an RCD.
If we compare electrical structures with boilers that burn fuel, we cannot fail to note the advantages of the former:
As for the disadvantages, today there is only one - the high cost of electricity. Nevertheless, the use of electric power plants in the absence of other options or as backup heat sources is not only justified, but also economically feasible.
Comparison of parameters of electric heating boilers
When starting to build a homemade heating unit, first of all, determine the required power. Based on this value, a conclusion is made about the advisability of choosing one type of boiler or another, further calculations are carried out, and the dimensions and number of components are determined.
Various sources provide several methods for determining the power of heating installations. The easiest way is to use the formula:
W = Wy × S (kW), where:
W - boiler power;
Wy - specific power for different regions (northern regions - 0.2, central - 0.12 -0.15, southern - 0.07);
S - heated area, m2.
To clarify the obtained values, the result must be multiplied by a correction factor:
Often, experts who install heating systems recommend calculating based on the norm of 100 - 150 W per 1 sq. m. m. depending on the region of residence. Of course, this method cannot be called the most accurate, however, it is suitable for a rough estimate. In other cases, it is still better to make a small reserve of power for unforeseen circumstances.
When choosing a cable for connecting an electric boiler, special attention is paid to the cross-sectional area of the conductor
Having received the desired value, be sure to analyze the parameters of your electrical network. It may be necessary to install an additional power line or reconstruct existing communications to connect equipment. It is best to consult the electricians of the energy supply company regarding these issues.
Before starting work, you need to select a suitable design, carry out the necessary calculations and prepare drawings, stock up on materials and tools.
As with any other home-made device, the use of ready-made drawings with exact dimensions when building an electric boiler is unlikely. Most likely, everyone will proceed from their own needs and the availability of this or that material. However, we have prepared drawings, diagrams and instructions for the manufacture of heating boilers of various types. Perhaps they will serve as an example for your own developments, or maybe one of the presented designs is fully suitable in all respects.
Diagram of a homemade induction boiler
Despite the sophisticated operating principle, induction boilers are simple in design, so they can easily be made at home. The only thing that can cause difficulties is the manufacture of a high-frequency voltage converter. If you do not have experience in building electronic devices, then it is better to entrust this part of the work to specialists. The electronic circuit presented below will allow you to power a boiler with a power of up to 5 kW. To make the task easier, you can use an inexpensive welding inverter to power the installation, connecting it in front of the output rectifier diodes.
Voltage converter circuit for induction heating boiler
Installation of such induction boilers is possible only in systems with forced circulation of coolant. Otherwise, the housing of the heating installation may melt. That is why the boiler is turned on only after checking the functionality of the circulation pump.
To make an induction heating boiler you will need:
Before starting work, you need to prepare the following tools:
Making an inductor
8. The ends of the coil are connected to a voltage converter. The electronic device itself must be grounded. We remind you that when using a welding inverter, you will need to open it and solder the leads of the inductor coil to the input of powerful rectifier diodes (they are installed at the output of the device).
9. After filling the system with coolant, the boiler is turned on and tested.
To regulate the temperature in the heating system, a thermostat is used, to the power part of which the power wires of the voltage converter are connected.
High-frequency electromagnetic radiation from induction devices can be shielded. To do this, use a steel or brass sheet installed at a distance, connecting it to the “mass” of the unit.
Drawing of a heating element electric boiler
The presented design of a heating unit with heating elements in the form of heating elements is characterized by simplicity and undemanding use of materials. Such a boiler can be used to heat a small room, installed in a bathhouse or garage, and to connect it you will need a regular household power supply of 220 V.
All that is required for its manufacture is sections of steel pipes for the body and pipes, sheet metal for flanges and one or two tubular electric heaters. By the way, for one heating element a pipe with a diameter of 100 mm is sufficient. If you need to install 2 - 3 heaters, then you will need a pipe with a diameter of 130 - 150 mm. As for the length of the body, it must exceed the linear dimensions of the heating element by at least 50 - 60 mm.
When using several heating elements in a design, each of them must be connected through a separate machine. In addition, if the house has a three-phase network, then it is better to connect the heating elements to different phases.
To manufacture a low-power 2.4 kW electric boiler, you will need the following materials:
The tools you need to prepare are:
In addition, you will need to prepare a rust converter, primer and paint to protect the finished product from rust and give it an aesthetic appearance.
1. We make a heat exchanger. To do this, you need to take a Ø120 mm pipe and make Ø1˝ holes in it at the connection points to the heating system. To do this, it is best to use a plasma cutting machine or gas cutter. In extreme cases, the spaces under the inlet and outlet pipes can be burned with an electrode.
2. The holes are cleaned using a grinder, after which the prepared bends Ø1.25˝ are welded.
The holes are cleaned using a grinder
3. A metal plate with a thickness of at least 5 mm is used as the bottom of the heating unit. It will cover the heat exchanger housing from below and will serve as a flange for a heating element of higher power. This option is the simplest, however, if the heater burns out, replacing it will not be easy. This drawback can be eliminated by installing a split-type flange.
Installation of the pipe
4. Squeegees of smaller diameter are welded in the same way as supply pipes. One of them is installed at the lowest point of the heat exchanger and is designed to drain water from the system. In the future, a ball valve will be installed on this outlet. The other pipe is intended for installation of a low-power heating element equipped with a thermostat. The third drive will be needed if the system needs to be additionally equipped with an expansion tank.
The heat exchanger is ready for installation of heating elements
5. From the wall side, a Ø6 mm stud is welded to the boiler body. You will need it to connect the ground.
6. Holes are drilled in the bottom plate for installing a powerful heating element, after which the heater is mounted, sealing gaskets are installed and the fastening nuts are tightened.
Holes for U-shaped heating elements
7. The upper part of the heat exchanger is covered with a round metal plate Ø120 mm, cut from a steel sheet with a thickness of at least 3 mm. After this, they are welded around the perimeter of the part.
Heaters are installed on sealing gaskets
The presented design has a significant drawback in the form of the impossibility of replacing the tubular heater. In order to perform this operation, the boiler will have to be dismantled and the top cover cut off with a grinder. This trouble can be avoided by using a split-type flange or rod heating elements that are installed in boilers. Of course, you will first need to weld threaded sockets into the heat exchanger for their installation.
8. The tightness of the welding seams can be checked in a large container with water, having previously covered the pipes with plastic film.
9. After installing the additional heating element, thermostat and ball valve, the boiler is connected to the heating system and the system is filled with coolant.
10. If there are no questions about the tightness of the system, the boiler is connected first to the ground loop and then to the electrical network. This is best done through a 25 A circuit breaker using an RCD.
11. At the final stage, operating voltage is supplied to the heating elements, after which the system is tested at maximum temperature and when the heaters are turned on separately.
The electric boiler will be ready for use after painting
To protect the boiler from corrosion, its surface is treated with a rust converter, after which it is primed and painted. Of course, it is more convenient to perform this procedure before installing the boiler in the heating system.
The electrode boiler shown in the drawing has a very simple design. However, you can modify it. For example, threaded plugs 4 can be eliminated by replacing them with tightly welded welders. Or use ready-made threaded pipes as pipes 3, welding them to the body.
1 - seamless iron pipe Ø57 mm with internal thread; 2 - coating of heat-resistant paint; 3 - coolant inlet and outlet pipes Ø32 mm with external thread; 4 - side metal plugs; 5 - internal electrode for boiler Ø25 mm; 6 - connecting terminals with M6 thread for connecting the neutral wire and grounding; 8 - gaskets made of rubber or paronite
To assemble an electrode boiler you will need:
Just like for the manufacture of other electric boilers, in this case you will need the simplest and most common tool:
Don’t forget about heat-resistant paint - the homemade product will need to be protected from corrosion.
1. Squeegees with internal threads are welded to the section of pipe - the boiler body, into which the plugs will be screwed. If you have access to a lathe, this operation can be simplified by using it to cut along the edges of the pipe.
2. In the places where the inlet and outlet pipes are installed, holes with a diameter of at least 25 mm are drilled. Spherical recesses are made at the edges of the bends for a better fit of the pipes to the body.
3. Squeegees and studs are welded to the main pipe, which will be grounding terminals.
4. A groove is made at the end of the electrode, after which a thread is cut on it.
When constructing a boiler, you can use electrodes from factory-made heating units
5. A hole equal to the diameter of the threaded part of the electrode is drilled in the fluoroplastic plug.
6. The internal electrode is installed in the plug and secured with a nut.
Electrode boiler parts are ready for assembly
7. The plugs are installed in place, the boiler is cut into the heating system and coolant for the electrode structures is poured into it.
After installing the heating unit, check the tightness of the connections, after which the grounding and power wires are connected. Voltage is supplied through a circuit breaker designed for 25 A and an RCD.
The boiler is adjusted using current clamps and a soda solution in a ratio of 1:10. The measuring device is installed on one of the power supply wires and the boiler is connected to the network. When adding a soda solution to the coolant, monitor the ammeter readings. It is necessary to achieve a current value of 18 A. In this case, the power of the heating unit will be about 4 W.
A self-assembled electric heating installation will provide warmth and comfort in the house and give you self-confidence. Working with your own hands will save you a lot of money for other projects. Just do not forget that using electricity will require extreme concentration and attention both during installation and during operation. When assembling a heating boiler, follow the recommendations of experienced craftsmen and listen to the advice of professionals. After startup, periodically monitor the operation of the installation and follow the rules for handling electricity. Only in this case will a homemade electric unit be useful, and its owner will be able to be proud of the work done.
