How to connect an electric heating boiler?

In this article we will not consider the process of connecting an electric boiler to radiators, cold water, filters and other elements of the heating system. To readers a part will be provided that is directly related to electrical work: connecting the electric heating boiler to the mains, grounding and installation of protective devices. Therefore, we will not take away your time and get down to business.

The advantage and scope of electric boilers

Most often, electric boilers are used for heating installation in the country and in a private house. This is due to the fact that this equipment has a low cost and you can install it yourself without calling a wizard.

Electric boiler on the wall photo

Among the main advantages of electric boilers are:

  • the equipment is safe (the design does not include an open flame or the presence of flammable sources of fuel);
  • water heaters can be in the off state for up to six months, while without harm to their performance (relevant for cottages and country houses, which are rarely visited);
  • the dimensions are relatively small, so you can place it in any room;
  • today there is a huge variety of electric boilers, different in power, installation method and principle of operation;
  • when water is heated, soot does not occur, which is dangerous both for humans and the environment.

Safety regulations

Before we move on to the main part of the heating installation, I would like to pay attention to the safety of electrical work.

Firstly, the connection of the electric heating boiler should be carried out with the power turned off.

Secondly, it is necessary to install it at a certain distance from other objects, namely:

  • there must be at least 5 cm of free space between the body and the walls;
  • the front panel should be accessible for maintenance, 70 cm of free space is enough;
  • the distance to the ceiling is not less than 80 cm;
  • the distance to the floor is not less than 50 cm (if the electric boiler is suspended type);
  • the distance to the nearest pipes is at least 50 cm.

Thirdly, the network must be three-phase (at 380 V) in order to reduce current loads on the wiring. When using a single-phase network to connect a powerful boiler, the wiring may not withstand, as a result of which it will spontaneously ignite and short circuit.

Fourth, all wire connections must be airtight and protected from water. Water can get on the contacts if the pipeline is damaged (for example, the coupler connected to the unit will burst) and when condensate drains from the ceiling (in an unheated room). It is also recommended to protect the cable with a corrugation or cable channel made of self-extinguishing material. If the wires ignite, these products will prevent the spread of flame.

Electrical wiring diagrams

So, to your attention there are several typical schemes for connecting an electric boiler in the house with your own hands:

As you can see, the projects are quite simple and consist of a water heater itself, a transportation line (pipes), a circulation pump and radiators. Your task is to correctly connect all the elements together, and then turn on the power.

Main process

Install the unit

First you need to install an electric boiler in the room. As we have said, the unit can be floor and wall. In the first case, the kit comes with a special stand, on which "landing" is made.Floor heater

In order to hang the boiler on the wall, it is necessary to prepare an anchor with dowels and a drill with a suitable drill. First, mark the wall with a tape measure and marker. The holes should be perfectly flat in the horizontal plane. Next, we drill the marked out places, hammer the dowels into them and screw the anchor. After the anchor sits firmly inside the wall, you can suspend the electric boiler.Wall mounted water heater

We draw your attention to the fact that the installation of an electric boiler should be performed perfectly evenly in both horizontal and vertical plane. Any skew can affect the performance and life of the equipment.


Since the electric water heater has a large capacity, it is necessary to connect it not from the outlet, but directly from the mains. To do this, it is necessary to withdraw a separate line from the junction box in the room to the boiler connection point. It is better to use cable routing in a hidden way, as in this case, the line will be protected from mechanical damage and the appearance of the room will not deteriorate.Electric installation work

It should be noted that to power the boiler it is necessary to use a cable of large cross section, which can withstand quite high current loads. How to implement it correctly cable section calculation, we spoke in the corresponding article, which we strongly recommend that you familiarize yourself with.

So we draw your attention to the fact that small heaters (up to 7 kW) can be connected to a single-phase network, which is often found in Khrushchev and old-style apartments. Well, the last nuance at this stage, which you should know about - electric boilers up to 3.5 kW can work from the outlet, and not from a separate line from the distribution box. Low-power boilers are ideal for connecting in an apartment, because in this case, the wiring is usually single-phase and making a new cable layout is not always an appropriate solution.

Install protective equipment

When all input wires are connected to the electric boiler, it will be necessary to further protect it. circuit breaker and RCDinstalled in the main shield. The purpose of the first device is to protect equipment from short circuits and wiring overloads. Connecting an electric boiler through an RCD will protect you from leakage currents.Installing a residual current device

Also recommendedconnect voltage regulatorbecause even small jumps can damage the unit.The fact that it is necessary to ground the electric boiler, I think, is not worth talking about. The main requirement is that the ground wire run directly from the bus to the equipment chassis.

We start

When all wiring elements are connected, it is necessary to check all the connection points. There should not be bare contacts, in fact, as well as damaged insulation.Start

It is also necessary to check all couplings, taps and pipe joints. Only after a quality inspection of the heating system can we proceed to its launch. First, open the valves to the equipment, then turn on the electric boiler.

Pay attention to the operability of temperature and pressure sensors. Nominal values ​​are indicated in the instructions that come with the kit. In case of obvious deviations, it is better to call the master.

We also provide you with a clear example of installation work:

DIY video instruction for connecting an electric boiler

How can I save?

Electric heating is quite expensive compared to gas. To make it economical, we recommend that you consider the following tips:

  1. Get two-rate counter electricity and turn on the heating at night. In the afternoon, as a rule, everything is at work and there is no need for the functioning of the boiler. It is better to warm the room well at night, because at this time the price for 1 kW of electricity will be much less.
  2. Use automation that allows you to turn on the heating at a specific time or only when the temperature drops to the set value. In this case, the unit will only work if absolutely necessary.
  3. The highest heating of radiators is achieved by placing the boiler at the lowest point of the heating system.
  4. Add a modern solution to the heating system - warm floor, it will allow more efficient use of the consumed heat throughout the room.
  5. We return to the use of double tariff meters. Another option for their rational use for heating is to buy heat accumulators. These water tanks can warm the room throughout the day, while the liquid will heat up at night (when electricity will cost much less).

That's all I wanted to tell you about installing and connecting an electric heating boiler with your own hands. Finally, we recommend that you buy devices only from quality manufacturers, so that the heating in the house lasts as long as possible. Among the leaders in the production of water heaters, there are three most optimal ones in terms of price and quality: Protherm (Proterm), Nevsky (we examined its connection in the video) and Galan.

Also read:

DIY video instruction for connecting an electric boiler

(9 votes)

Add a comment