Heating using electricity is not very profitable, but it gives a lot of advantages: comfortable operation, relatively low price of equipment, safety. This article is about installing and connecting an electric boiler in a private house. Having studied our detailed guide, any skilled homeowner will easily install an electric boiler with his own hands.
If you have not chosen an electric boiler
The choice of a heater operating in conjunction with a water heating system is performed according to the power and the principle of operation (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 are connected to it - weather sensors, room or overhead thermostats and GSM modules for control from a mobile phone or via the Internet.
Important notice. Some manufacturers, for example, Galan, Protherm or Evan, require in the operating instructions that specially trained personnel carry out the installation and connection of the electric boiler to the network. Independent connection will result in a disclaimer of warranty.
Before choosing and buying a heating device, specify how much electric power is allocated to your home by the management company. It may turn out that it is not enough for individual electric heating. The second moment: a single-phase network with a voltage of 220 volts is able to power boilers that consume up to 12 kW / h inclusive. More powerful water heaters are connected to a three-phase 380 V.
Determination of thermal power
This indicator is calculated according to the standard formula: calculate the heated area of a country house or cottage, then multiply the quadrature by 0.1 kW. Get the need for thermal energy that the electric boiler needs to shut down.
Consider a number of nuances:
- the ceiling height of the rooms is up to 3 m, otherwise the calculation is based on the volume of the premises: the cubic capacity is multiplied by 40 W;
- the heat generator must be selected with a minimum margin of 20%;
- if the heating unit is planned to be used to provide domestic hot water, the supply should be at least 50%;
- in the northern regions, the building quadrature is multiplied by 0.2 kW, in the southern regions - 0.08 kW;
- the power of the boiler, which works only at night and charges the heat accumulator, is taken with a double margin.
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. Water heating is necessary for household needs - we multiply by a factor of 1.5 and get 15 kW.
To obtain more accurate results, we suggest studying the methodology for calculating the load on the heating system
Which type of heater is better
Next, you need to choose a water heater according to the principle of operation. What types of household electric boilers can I buy:
- Traditional, equipped with tubular electric heaters (heating elements).
- Electrode, where the salted coolant is heated by the passage of current through water.
- Induction apparatuses heat the fluid with Foucault eddy currents arising in the metal core of a multi-turn coil.
Valuable advice. Do not listen to the tales of sellers who praise the efficiency of one or another electric boiler. They like to use the terms “energy-saving”, “eternal”, “economical” and so on. Remember: all types of heaters equally efficiently convert electrical energy into heat with an efficiency of 98-99%.
The first place in the ranking of users is taken by heating elements.The only weak point - the heating element itself - has long been protected by ceramics, 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 a 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:
- loud sounds of inclusion from operation of the contactor or magnetic starter;
- gradual degeneration of salts in the coolant, reducing the heating efficiency, because of which the water in the heating system will have to be salted 1-2 times a month;
- the electric device works stably with radiators, but is poorly compatible with warm floors, where it is necessary to maintain a low coolant temperature of 35-50 ° С.
Induction electric boilers for heating a private house 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 fell by a third. To fix the breakdown is very problematic.
Heater Installation Instructions
Electric boilers of all types are designed for wall mounting and are equipped with mounting brackets or clamps. It makes no sense to explain the marking and driving of dowels - every homeowner knows how to do it.
For reference. In the floor-mounted version, universal electric-wood and coal-fired boilers are sold, described in our other material.
Another question is how to choose the right room and the specific installation location of 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), imposing restrictions on the placement of high-power thermal devices.
Let's give some general recommendations on how to properly install an electric boiler in a private house:
- Given the high current in the circuit of working electric heaters, it is better to install the devices in a separate technical room, for example, a furnace or garage. The goal is to limit access to power electrical equipment and protect devices from moisture.
- Heating mini-boiler rooms can be placed in the kitchen or hallway. But consider an important nuance: there you have to pull the main heating system main and a powerful power cable. It is unlikely that these communications will harmoniously fit into the interior, except to plug the pipes into the wall.
- When mounting the heat generator on a wooden wall or other combustible partition, observe the requirements for mounted gas boilers. Lay a sheet of roofing steel or basalt cardboard under the back of the cabinet adjacent to the tree, as shown in the photo.
- Provide access and access to the heater for easy connection and maintenance. Install induction and electrode boilers in such a way as to place an expansion tank and a pump nearby. Place the control cabinet at a height of 1.5-1.8 m from the floor.
- Lay the cables above the heating and sewer pipelines so that they are not flooded with water in case of a breakthrough.
- Heating pipes must not weigh the unit connecting fittings with their weight.
Important! Be sure to attach the boiler body to the ground bus. If one is missing, make a ground loop on the street and lay in the boiler room. Find detailed instructions below.
As a rule, an electric heat generator acts as a backup apparatus for the main solid fuel or gas boiler. So, you need to properly assemble the heat generators and auxiliary equipment so that a minimum of pipeline crossings is reached. Ponder and draw a diagram in advance.
Tying an electric boiler with a heating system
Wall-mounted mini-boiler rooms with an integrated expansion tank, pump and safety group are operated in closed pressurized heating systems. The connection is extremely simple and does not need to be displayed in the form of a diagram: the supply and return pipes are connected to the corresponding pipes of the electric boiler.
Note. The automation of such heat generators monitors the pressure in the heating network through a sensor. If the coolant pressure is below the set threshold (usually 1 Bar), the device will not turn on.
Next, we want to introduce typical schemes for connecting electric boilers to heating systems for such cases:
- when you need to install a unit that is not equipped with its own pump and expansion tank;
- parallel operation paired with a solid fuel or gas boiler;
- strapping with buffer capacity;
- connection of the double-circuit version of the unit to heating and domestic hot water lines;
- connection to an indirect heating boiler.
The first diagram illustrates the connection of an electrode or induction boiler to a closed heating network with a membrane expansion tank. A safety group is placed on the direct outlet section of the supply pipe, followed by a shut-off ball valve. The pump and filter - sump with equal success are placed on the feed or return.
Note. In this and subsequent diagrams, the make-up pipeline is not conventionally shown. It should be cut into the return heating pipe.
In a similar way, the heating element of the electric boiler, not equipped with an expansion tank, a safety group and a pump, is connected. If it is necessary to organize a connection to a gravity-fed (gravity) open-type heating system, the pipelines are laid with a slope of 3 mm per meter, and the circulation pump is mounted on the bypass.
An open expansion tank is located at the top 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 capacity of 2 meters. Accordingly, the tank is taken out to the attic of a private house.
Comment. Installation of a wall-mounted electric boiler, whose pipes are turned down, will not allow the coolant to circulate naturally due to convection. An example is aggregates of the Evan or Proterm brand. Heaters with side and top fittings - Galan, VIN and the like - are suitable for gravity systems.
Connection with other boilers and heat accumulator
To connect an electric heat generator together with a solid fuel boiler, use the circuit with two check valves, a thermostat and a room temperature controller. This connection option provides automatic “pick-up” of the cooling system by an electric boiler after burning through the laying of firewood.
The algorithm of the circuit looks like this:
- The TT-boiler acts as the main one, the electric apparatus is in standby mode.
- When a portion of wood or coal burns out, the air temperature in the building begins to decline. When cooling to a threshold set by the user, the room thermostat switches on the electric heater.
- The on-board thermostat detects a temperature drop in the return of a solid fuel boiler and turns off its pump.
- After loading firewood into the firebox, heating is resumed, the thermostat starts forced circulation. Using its own sensor, the electric boiler “sees” the heated coolant and is not included in the operation until the next command of the thermostat. More details about the principle of operation are described by the expert in the following video:
Note. The strapping method is also suitable for other types of boilers - gas, diesel and so on. Consider one caveat: the electric heater is used as a backup heat source.
Connection to the 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, using a cheap rate. During the day, the apparatus is inactive, and the building is heated by heat from the buffer tank.
The task of the mixing unit with a three-way valve is to supply radiators with water of the required temperature, because the heat accumulator “charges” to 80-90 ° C. If the water circuits of the floor heating are arranged in the rooms, a second mixing unit is made for them, which prepares a coolant with a temperature of 35–45 ° С (maximum - 50 ° С).
Hot Water Schemes
There are two ways to get hot water from an electric boiler for household needs:
- purchase and supply a dual-circuit heating unit;
- connect an indirect heating boiler to a single-circuit boiler.
In the first case, the device is connected according to the standard scheme shown in the picture. Minimum complexity here, the main thing is to correctly mount the stop valves.
Tying with an indirect heating boiler is carried out through a three-way switching type electrovalve. At the command of the thermostat built into the storage tank, the element switches the flow of the coolant to water heating for domestic hot water or heating radiators. Boiler loading is a priority: until the tank warms up to the set temperature, the radiator network will not receive heat.
An important point. For this reason, a large role is played by the selection of the power of the heat generator. If it is not enough, the heating of the tank will stretch for a long time, room air will have time to cool. For more information about the system, see the training video.
Although the plot is about docking the storage water heater with a wall-mounted gas boiler, the essence does not change - the electric heater is connected in the same way.
Mains connection
Power schemes are the same for all electric boilers, the difference is only in the number of phases. Devices with a capacity 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 will be needed for installation:
- power cable with copper conductors;
- differential circuit breaker or RCD bundle + conventional circuit breaker;
- ground loop.
A VVG brand cable of any kind is used as the 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 instruction manual. To simplify the task, we present the data for different boilers in the form of a table.
The value of the differential machine also depends on the power consumption of the heater, the response current is 30 mA. For example, to protect the power line of an aggregate of 3 kW (220 volts), you need a device rated for 16 A, for a power of 16 kW (380 V) you need a 32 A difavtomat. The exact ratings are indicated in the product passport.
To independently connect a wall-mounted electric mini-boiler room, it is necessary to remove the front panel, route the power cable inside and connect the wires of the corresponding colors to the terminals of the terminal block. As a rule, the neutral wire is marked in blue, grounding is yellow-green. In the same way, the control box of the induction and electrode boiler is connected.
Electrical connections between the control cabinet and the heating unit of the electrode or induction boiler are made according to the individual scheme presented in the instructions. As an example, we give the connection diagram of the popular electric boiler "Galan".
Here, the temperature of the coolant is controlled by overhead sensors installed on the metal sections of the supply and return pipes. Devices are connected in series with the contacts of the thermal relay controlling 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 ground loop near a private house is a simple and very useful thing from the point of view of electrical safety. For installation, look for 3 steel rods Ø16 mm 2 m long and a strip with a section of 40 x 5 mm.
3 meters away from the wall of the building, arrange grounding according to the step by step instructions:
- Mark a triangle with 2 m sides on the ground and dig a pit to a depth of 50 cm.
- Sharpen the ends of the rods with an emery or grinder, set at the vertices of the triangle and hammer into the ground to the full length.
- In the pit, the protruding ends of the rods are securely connected by a strip by welding.
- Make the feed bus from the strip by welding it to the loop and securing it to the base. Grab a bolt to it, fasten the copper bus and lead the ground electrode into the house, connecting the electrical panel to the metal case.
At the end, welds and the aerial section of the strip are treated with bitumen, bury the hole. For more information about the grounding device for an electric boiler and home appliances, see the video:
Conclusion
In order not to make stupid mistakes in the process of installation and strapping, before installing an electric boiler, you should talk with 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.