Combined indirect boiler

In modern construction a very important component is not only the erection of the box of the building, but also the creation of comfortable conditions for living and carrying out all the communications. One of the first on this list will be the heating of the living space. The availability of hot water is also an important detail. If there is no possibility of a centralized system, autonomous equipment will come to the rescue. To perform exactly these tasks perfectly suited combined boiler indirect heating.

The main distinguishing feature of such units is to use the heating system in winter and be a direct heating boiler, bypassing the heating system in summer.

• In the winter, when the heating system works at full, together with the boiler operates a single-circuit boiler. From it the hot water is supplied to the heat exchanger, and this is how the water is heated.
• In the summer, when there is no point in the boiler operation, the boiler can work independently. Both electricity and gas can be used to ensure its operation.

The positive aspects of such a unit are not without reason considered:

• The long service life of the unit;
• there is no need to buy fuel supplies;
• It is possible to choose the energy on which the boiler will work - electric, gas, solar;
• Good power allows you to heat water quickly enough.

Along with quite an impressive list of advantages, there are also disadvantages:

• there is a need to purchase additional devices. At least a circulating pump;
• The need to consider the boiler at the design stage of the house;
• dependence on the proper functioning of the heating boiler.

Combined boiler is a device that is able to receive energy generated by extraneous sources. In terms of its structure, it is not so complicated: it is a tank covered with a thermal insulation layer. The capacity can be from 20 liters to several cubic meters.

For the first time such a device appeared inside the chimneys around heating batteries, it was called "coil". Although it looked more like an indirect flow water heater. Now such a coil is installed in the internal tank of the boiler. The flow, carrying heat, heats the water, which is used for DHW.

Based on the conditions in which the device is used, of what kind of water flow is required, different water heaters can be installed, which have a different set of functions and features.

• Flow-through type. The most famous modification is a gas water heater. Their use is possible only if the problem of combustion products removal and installation of additional ventilation is solved.
• The usual electric boiler. If there is no possibility to use gas-fired equipment, then the water will be heated by the well-known device.
• Two-circuit gas boiler. A significant disadvantage of such a system will be almost twice as much gas consumed. Savings can be achieved by changing the components to a simple single-circuit boiler and adding a combination boiler to it. Otherwise, the system can provide quite high water consumption.

Most often used floor combined boilers of indirect heating.

The market in this segment is represented by a fairly wide range. The most popular manufacturers of combined indirect heating boilers:

• ACV (Belgium);
• Austria Email (Austria);
• Baxi (Italy);
• Drazice (Czech Republic);
• Oso (France);
• Stiebel Eltron (Germany);
• RUBOILER (Russia);
• Vaillant (Germany);
• Heatleader (Serbia);
• Lapesa (Spain);
• HAJDU (Hungary);
• Metalac (Slovenia);
• S-Tank (Belarus);
• Unitherm (Germany);
• SDM hotwater (Russia);
• GOPPO (Russia).

Prices for such products vary greatly. If you can pick up at a reasonable price apparatus of Russian, Czech, Spanish production. Although, if we talk about the prices of the Spanish brand Lapesa, it is from 60 thousand rubles to a million, because they are the only ones in the world that protect the weld from the inside. The average cost of the Belgian, German and French producers is 300 thousand rubles.

The strapping of the indirect heating boiler means the connection of the boiler pipes to the water supply. The operation of the system as a whole depends on how the installation will be carried out.

There is a nuance here - the temperature you set on the thermostat must be set higher than the temperature that is set in the heater! Otherwise it is not possible to heat the water to the point at which the heating circuit is switched.

Another variant of piping is with the parallel use of two pumps. One is installed for the heating circuit, the other for the hot water supply. Management of pumps as well as in the first case is entrusted to the thermostat. It performs the switching of the operating mode.

The quality of heating remains at a high level.

If the heating system has many branches, such as a multi-circuit battery system or a separate branch to the floor heating, then it makes sense to use this type of piping. To avoid difficulties with a system in which each circuit has its own recirculation pump, a hydraulic distributor is used.

The hydraulic manifold must balance the pressure in each direction and prevent heat shock.

• Ahead of the maximum price you are willing to pay for the boiler.
• Determine the capacity of the unit. The speed of heating directly depends on it.
• Select the size and dimensions.
• Check the degree of protection and insulation.
• Consider all service centers and whether they are available in Russia.
• Check the warranty of the product.

Before choosing a combined indirect water heater be sure to familiarize yourself with the principles of operation and general recommendations.

In the following video Sergei Volkov you can see how to install a combined indirect water heater and why this device is so convenient and popular.