Of the wall-mounted gas boilers offered on the market, only double-circuit boilers provide consumers with hot water without connecting additional devices. The performance of such a hot water supply system often does not suit the owners, so wall-mounted gas boilers with a boiler built into the body have appeared on the market. This technical solution made it possible to significantly increase the capacity of the hot water supply.

In practice, the following options are used:

• wall-mounted gas boilers with built-in boiler;
• connection of remote storage tanks;
• installation of indirect heating boilers.

The hot water supply system in double-circuit boilers can be organized in different ways. The circuit can be flow-through or accumulative. The flow circuit with intensive selection does not have time to heat the water to the desired temperature due to low productivity. The accumulative boiler works much better and if you choose a gas boiler with a built-in boiler with a capacity of about 50 liters, it will fully meet the water needs of a family of 3-4 people.

Remote storage tank

The possibilities of wall-mounted gas boilers to increase the productivity of hot water are limited by the size and capacity of the built-in boiler. According to the classification of gas boilers, a gas boiler with a boiler should have a weight not exceeding 50 kg, however, wall-mounted boilers are produced in which the built-in boiler has a capacity of about 100 liters. This is the limit value, otherwise the weight and dimensions of the boiler will make it impossible to mount it on the wall.

How to solve the problem if the installed double-circuit gas boiler with a boiler does not provide the necessary hot water needs?

The solution is simple, you need to install a remote hot water tank, which can be up to 500 liters. Almost all wall-mounted gas boilers with a boiler inside are designed for the simultaneous connection of an external storage boiler. The design provides branch pipes and a circulation pump is installed, which serves only the DHW system. The maximum capacity of the external boiler depends on the capacity of the boiler, because if the capacity is low and the capacity is too large, the temperature will never reach the desired value.

How a boiler works with an external boiler

Usually, the automation that controls the operation of a wall-mounted gas boiler is programmed for the priority of the heating system.

When the temperature of the coolant in the circuit drops, the burner turns on and the wall-mounted gas boiler with a boiler heats the water in the batteries to the desired temperature.

After receiving a signal from the water temperature sensor in the circuit, the controller will switch all the power with to the DHW circuit. To maintain the temperature of hot water at a certain level, a gas boiler with an indirect heating boiler is equipped with a built-in heating element, which is connected to the electrical network, and the control is carried out by the boiler automation controller.

Can a boiler be used for heating?

Undoubtedly, the question of how to make heating from a boiler worries many homeowners. This option captivates with its simplicity, but one should also take into account the presence of significant drawbacks of such a heating system. What is needed for the heating circuit? The device that heats the coolant is a boiler for heating the house, which in this case plays the role of a boiler, to which pipelines and radiators must be connected. Just? Yes, but it is this apparent simplicity and cheapness, as well as the minimum required additional equipment, that encourages owners to use a boiler for heating. But not everything is so simple.

Difficulties in connecting a boiler for heating:

Kitchen design with gas equipment

You can perfectly fit any type of boiler into the design of the kitchen if you know the simple rules. The organic design of a kitchen with a gas boiler is disguising it as existing details.

The following methods are most often used to create an original kitchen interior:

If the masking method does not fit, then you can apply a more complex method of fitting the boiler into the interior of the kitchen. When designing, you need to select or order furniture in which a gas boiler and other household appliances will be hidden. In this case, certain rules and requirements of gas equipment manufacturers must be observed.

List of requirements for installing a gas boiler:

Today, the best solution, as a result of which a private house is fully provided with sufficient hot water, is the use of wall-mounted gas boilers with built-in or remote storage boilers. Even a single-circuit gas wall-mounted boiler whose price is less than that with an external storage tank will provide the home not only with heating, but also with hot water. The performance of such a switching circuit is much greater than that of a two-circuit DHW flow circuit.

Equipped with a stratified heating boiler, it is confidently conquering the market and the hearts of homeowners. However, manufacturers of heating equipment are confident that a number of models with a tubular heat exchanger can confidently compete with it. The fact is that in some cases, units with layered heating fail very quickly. In this article, we will reveal possible alternatives to such a device and tell you many technical nuances.

Pipes and plates: what is the fundamental difference?

The traditional tubular heat exchanger is a small diameter tube laid in a spiral. Water for the heating system and hot water moves inside, receiving heat. The system is practical, but rather bulky, since high-power models are equipped with a free-standing boiler. Often, for the organization of the boiler room, you need to allocate a separate room.

The problem was solved when stratified heating boilers appeared. Inside such a unit is a series of plates, between which a small space is left. These plates heat the water circulating in the boiler. As a result:

• water heats up much faster than in a tubular boiler;
• the boiler is built directly into the gas boiler;
• the device is very compact;
• the cost of equipment is noticeably lower than when using a traditional heat exchanger.

However, many homeowners soon discover that stratified heating also has a number of disadvantages. Mineral deposits form on the plates, the space between them becomes clogged and the unit fails. It is especially important to consider this feature of plate heat exchangers in areas where the water is characterized by increased hardness.

In a plate heat exchanger, water warms up to about 80 degrees, which contributes to the active settling of deposits and clogging of narrow channels. If the mineral content is more than 140 mg/l, it is recommended to abandon the plate heater in favor of alternative devices.

An alternative is more compact models of double-circuit gas boilers, equipped with a built-in indirect heating boiler. Minerals can also be deposited on the pipes through which water moves, but this process proceeds much more slowly than with layer-by-layer heating. The design of such a boiler practically does not differ from a set of a single-circuit boiler and a boiler with a tubular heat exchanger. Both of these elements, as well as pumps and other fittings, are built into a neat, compact housing.

Please note that minerals also settle on the tubular heat exchanger, although this happens quite slowly. For efficient operation of the boiler, it is recommended to clean it every few months. In addition, to reduce the rate of sludge formation, the heating control should be set to 54 degrees or lower.

This diagram clearly shows the difference in the operation of the two types of boilers described above.

Which option is suitable for a large area?

Experts believe that for a large house hot water system, a tubular heat exchanger is preferable to a plate heat exchanger. Since the distance from the heater to the point of water intake can be considerable, it is necessary to wait quite a long time until the cold water drains. The problem is solved with the help of a recycling system. This is a segment of the plumbing system, through which hot water circulates between the heater and the point of analysis constantly, maintaining the set temperature. Such a device cannot be used with a plate heat exchanger, since mineral deposits will form on the plates very intensively.

In a small house, the size of the equipment is important. The best choice can be a compact boiler, which is inserted into a large tubular heat exchanger. In this case, the pipes are placed in a spiral along the entire height of the boiler in order to quickly heat the entire volume of water at once. The efficiency is increased by the correct arrangement of the coil, for example, in the form of two parallel spirals. Such a device allows you to comfortably use even a small boiler, with a volume of only 10-20 liters.

Vaillant gas double-circuit coppers - an optimum combination of quality and reasonable price. This heating equipment has long been known and enjoys well-deserved popularity.

A few words about the performance of the boiler

When choosing a boiler, it is important to correctly evaluate its performance. Often, the manufacturer indicates only the initial performance, which is taken into account with a full tank of hot water. It is more important for the consumer to take into account the performance that the boiler produces with a regular flow of water. This figure is significantly lower than the original performance.

Another important point that affects performance is the increase in temperature. The lower this indicator, the longer the boiler will work, and the less breakdowns there will be. Indicating the performance of the boiler, manufacturers are guided by various growth data. In general, the rule should be followed: the greater the power of the equipment and the volume of the boiler, the more productive the equipment.

More information about choosing a gas heating boiler is presented in the video:

We bring to your attention an online calculator for selecting a boiler, depending on the characteristics of your room:

For home heating, you can choose a combined system. How to do it, you will learn in our article:.

Overview of manufacturers and prices

An interesting line of double-circuit gas boilers with a built-in boiler is the Italian manufacturer Baxi. Popular floor and wall models such as:

• Baxi Slim 2.300i;
• Baxi SLIM 2.300Fi;
• Baxi NUVOLA 3 COMFORT 240Fi;
• Baxi NUVOLA 3 280B40i;
• Baxi NUVOLA 3 COMFORT 280i.

Most gas boilers are equipped with electronic self-diagnosis systems, flame control, overheating protection and other safety modules. There is electronic ignition, the possibility of switching to liquefied gas, a programmable timer, etc. Prices vary in the region of 1500-2000 dollars.

Double-circuit gas boilers Baxi with a built-in boiler are compact in size, attractive in appearance, convenient control panel and the ability to automatically control the operation of the equipment

Gas boilers from another popular Italian manufacturer, Ferroli, are no less in demand. Most often, buyers choose models:

• Ferroli DIVAtop 60 F 32;
• Ferroli DIVAtop 60 F 24;
• Ferroli DIVAtop 60 C 32;
• Ferroli PEGASUS D 30 K 130;
• Ferroli PEGASUS D 40 K 130.

These gas double-circuit boilers are varied in terms of power and type of installation (floor and wall), but all are distinguished by increased corrosion resistance and a convenient control panel with an LCD monitor. Outside, the heat exchanger is covered with a layer of aluminum anti-corrosion composition, inside there is an ionization electrode for protection against electro-chemical processes. Almost all models are equipped with electric ignition, two control microprocessors, pump blocking protection, etc. The cost of Ferroli gas double-circuit boilers varies in a fairly wide range: from $ 1,200 to $ 3,000.

Double-circuit gas boilers of the Italian manufacturer Ferrolli are well known on the market. Their main feature is European quality standards and increased reliability.

Nova Florida double-circuit gas boilers, which appeared on the market relatively recently - in 1992, are distinguished by high quality. It is a trademark of the Italian company Fondital. Most often, buyers pay attention to the models:

• Nova Florida Libra Dual Line Tech BTFS
• Nova Florida Libra Dual Line Tech BTFS 28
• Nova Florida Libra Dual Line Tech BTFS 32
• Nova Florida Pegasus Compact Line Tech KBS 24

Compact wall-mounted boilers of this brand are relatively inexpensive: $ 1200-1500. The price of more powerful models can be $ 2500-3000. Methane or liquefied gas can be used to operate the boilers. The equipment has a high degree of electrical protection, the control panel is equipped with a convenient LCD monitor. It is possible to automatically control the operation of the boiler using room and external temperature sensors.

Advice! Due to temperature changes, the enamel coating of the case cracks. A stainless steel body is more practical in this regard, although such boilers are more expensive. The anode located in the tank increases the resistance of the equipment to electrochemical corrosion.

Cast iron floor gas boilers are usually cheaper and are equipped with a single-level burner. To regulate the operation of such a boiler, it is necessary to install a mixing unit into which an automatic three-way valve is built. As a result, the savings will be minimal. Good opportunities for reducing heating costs are provided by condensing models, which use the energy generated during the condensation of steam.

The floor gas boiler with a boiler is distinguished by the ability to quickly supply hot water in the required volume. The storage tank can hold from 40 to 500 liters.

Double-circuit gas boilers with a built-in boiler for hot water supply are essentially single-circuit units with an indirect heating tank, combined into one compact system. Such heating devices are equipped with a heat exchanger, which heats the water between heating support. Thanks to this design, there will always be a supply of warm water in the gas boiler. Examples of units are the Protherm Bear 30 KLZ models with a 90 l boiler, Baxi GALAXY 280 i with a 100 l capacity, Beretta Boiler 28 BAI with a 60 l boiler.