How to connect the boiler to the mains?

It is customary to use an electric boiler to heat the water needed for bathing and technical needs. This type of water heater, due to its small size, can be installed anywhere: in the bathroom, in the kitchen, in the toilet and even under the sink if the unit is flow type. Next, we will consider where and how to properly connect the boiler to the mains with our own hands.

Scope of a water heater

It is very rare to talk about using an electric boiler for heating, but still there is such an option. It is recommended to use it if the room does not have a complicated heating system, and the power of the unit is sufficient for normal operation (usually 1 kW can serve 10 sq.m.). In order for him to heat a small house, it is necessary to additionally install a circulation pump, otherwise hot water will not be able to efficiently spread through radiators (there will not be enough pressure).Flexible hose tightening

We draw your attention to the fact that there are accumulative and flow-through devices. The first version of the electric boiler consumes less electricity to heat, but requires a certain place to place the tank. The second option is more compact, but because of its increased power it consumes an order of magnitude more electricity.

Electrical Requirements

To readersmy.electricianexp"Did not endanger their lives and were able to connect the electric boiler to the network without problems, we provide a few simple rules that you need to consider:

  1. Be sure to turn off the power on the main panel during installation work.
  2. Connect wires only through terminal blocks or by soldering. There should not be any "grandfather" twists.
  3. Take care of water heater protection RCD and grounding. If the house has a two-wire network, be sure to make a grounding system on the site. As for the apartments of the old type - Khrushchev, in which very often there is no grounding, you can get out of this situation by connecting the boiler through an RCD and an automatic machine. You can also connect to the mains via difavtomat, which combines two types of protection. In the event that there is no “land” in the country, difficulties should not arise, because PE protection is not at all difficult to do with your own hands.
  4. Since water will pass near electrical appliances, take care of high-quality protection of the wiring from moisture. Purchase sockets with a degree of protection of at least IP44, circuit breaker and RCDs must be in a waterproof housing.
  5. If the unit will connect directly to the network (not via an outlet), use a non-combustible cable VVGng or its better performance - NYM.
  6. Wall mounts must be reliable. As a rule, the tank capacity can reach 100 liters.The thickness of the anchor in this case should be at least 8 mm. It is not recommended to install a boiler on a drywall wall. In this case, it is better to place the water heater on the floor.

Main process

Instructions for connecting the boiler to the mains will be provided from the moment the entire heating system is brought to the installation site. All that remains for you is to hang the water heater on the wall and connect it to the power supply.

Wall mount

Consider a more complex option, when the installation of a storage boiler will be applied, as installation of a through-heater is less time-consuming (due to the lower weight and dimensions of the product). First you need to mark the wall in accordance with the location of the fasteners. To do this, measure the distance necessary to install the mounting ears, and transfer it to the wall. Be sure to use the construction level so that the ears are placed horizontally.

Any skew will affect the performance of the unit, and therefore, its service life and efficiency of use. The tank should be placed perfectly evenly in both horizontal and vertical planes.

After marking, we take a drill, drill holes in the wall and drive dowels into them. Next, we screw in anchor hooks into them and hang the boiler on the wall, as shown in the photo below.

Do not worry about the decorative wall decoration. Even if repairs have already been made in the apartment, with careful installation you will not damage the surface. You can also see detailed instructions for installing and connecting a wall-mounted boiler in a video example:

How to install a water heater on a wall

Wire connection

When the water heater is securely mounted on the wall, you must independently connect the wiring to it. Consider two existing options for connecting wiring from the meter.Connection diagram of the boiler to the network

Option 1 - Power Outlet

This option is used if the unit power does not exceed 3.5 kW. In this case, it is necessary to bring the socket to the place where the boiler is connected to the electric network, as shown in the diagram above. The minimum cable cross-section must be 2.5 mm.sq. (copper conductors). Recommended in advance cable section calculationso that he can withstand the arising loads.Power Outlet

Option 2 - Power from the shield

If you purchased a device with a power exceeding 3.5 kW, it is forbidden to use power from the outlet, because it simply can not withstand such a load. In this case, it is necessary to bring the cable to the water heater directly from the distribution switchboard installed in the apartment or house.

It should be noted that the boiler can be connected to a single-phase network if its power is not more than 4 kW. If the rated power is higher, the network must be three-phase (voltage 380 Volts).

After you decide on the method of connecting the boiler to electricity, you need to power up the device yourself and proceed to the next step. The video below discusses various schemes for connecting a water heater:

Electrical wiring diagrams

Security setting

Since when you create a heating system, you will have to deal with powerful equipment, as well as the proximity of water and current, you need to take care of protecting the boiler and yourself.Installation of automation

First of all, you need to implement RCD connection and a circuit breaker to the line that will service the unit. If the power will come from the outlet, it is recommended to install protective equipment on the switchboard. In the event that the power will come directly from the shield, the protection devices should be near the object itself so that it can be conveniently and safely serviced. Do not forget that with the close location of RCDs and ABs, it is necessary to protect the devices from moisture.To do this, it is recommended to place the products in an airtight box.

RCD in a protective box


In a 220 V network, it is imperative to connect the electric boiler through a two-pole circuit breaker. Remember the important rule - the automation is installed with the top connection of the input phase and zero.

First start

When all electrical work is completed, you should proceed to start up the equipment. First thing is to check everything wire connections and pipes for integrity and tightness. If no deviations are found, you can proceed to turn on the power. To do this, first open the valves on the pipes (cold and hot circuit), after which you can turn on the machine and RCD. We strongly recommend that you watch the video instruction, in which the whole process is examined visually:

Video lesson: connecting an electric boiler to the network and the pipeline


The installation and connection of an electric boiler for heating is recommended for small houses and apartments. In cottages and spacious private houses it is better to implement electric boiler connectionbecause it is more powerful and able to heat the room more efficiently. If you are nevertheless configured to use this type of water heater, be sure to add a circulation pump to the system so that the hot water under pressure passes into the radiators, thereby warming the rooms more efficiently.

Related materials:

How to install a water heater on a wall

Electrical wiring diagrams

Video lesson: connecting an electric boiler to the network and the pipeline

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