An overview of alternatives to a dual-circuit boiler with a built-in boiler

Double circuit gas boilerequipped with a hot water boiler confidently wins 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 layer-by-layer heating very quickly fail. In this article we will reveal possible alternatives to such a device and tell you a lot of technical nuances.

Pipes and plates: what is the fundamental difference?

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

The problem was solved when layer-by-layer boilers appeared. Inside this 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 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 significantly lower than when using a traditional heat exchanger.

However, many homeowners soon discover that layer heating 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 water is characterized by increased rigidity.

In a plate heat exchanger, the water warms up to about 80 degrees, which contributes to the active sedimentation of sediments and clogging of narrow ducts. 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 was the more compact models of double-circuit gas boilers equipped with a built-in indirect heating boiler. Minerals can also be deposited on pipes through which water moves, but this process is much slower 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 case.

Please note that minerals also settle on the tubular heat exchanger, although this happens rather 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, a heating control should be set at 54 degrees or lower.

This diagram illustrates the difference in the operation of the two types of boilers described above

Indirect heating boiler can be made independently. Read more about this in our material:https://aquatech.tomathouse.com/en/otoplenie/boilery/bojler-kosvennogo-nagreva-svoimi-rukami.html.

Which option is suitable for a large area?

Experts believe that for the domestic hot water system of a large house, a tubular heat exchanger is preferable to a plate heat exchanger. Since the distance from the heater to the water intake point can be significant, it takes a rather long time to wait until the cold water drains. The problem is solved using a recirculation system. This is a segment of the water supply system through which hot water circulates between the heater and the breakdown point constantly, while 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, equipment dimensions are important. A compact boiler in which a large tubular heat exchanger is inserted can be the best choice. In this case, the pipes are placed in a spiral along the entire height of the boiler in order to quickly heat up the entire volume of water at once. The correct location of the coil, for example, in the form of two parallel spirals increases the efficiency. Such a device allows you to comfortably use even a small boiler, with a volume of only 10-20 liters.

Vaillant gas double-circuit boilers - the optimal combination of quality and reasonable price. This heating equipment has long been known and enjoys well-deserved popularity.

A few words about boiler performance

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 productivity that the boiler gives out at a regular flow of water. This figure is significantly lower than the original performance.

Another important point affecting performance is the increase in temperature. The lower this indicator, the longer the boiler will work, and the less damage there will be. By indicating the performance of the boiler, manufacturers are guided by various data on growth. In general, you should adhere to the rule: 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:

To heat the house, you can choose a combined system. How to do it, learn in our article:https://aquatech.tomathouse.com/en/otoplenie/razvodka-otopitelnoj-sistemy/radiatory-plyus-teplyj-pol.html.

Overview of manufacturers and prices

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

• Baxi SLIM 2.300i;
• Baxi SLIM 2.300 Fi;
• 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, overheat protection and other safety modules. There is electronic ignition, the ability to switch to liquefied gas, a programmable timer, etc. Prices vary in the region of 1500-2000 dollars.

Baxi dual-circuit gas boilers with an integrated boiler are distinguished by compact dimensions, attractive external design, convenient control panel and the ability to automatically control the operation of equipment

No less popular gas boilers of another popular Italian manufacturer - Ferroli. Most often, customers 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 diverse in power and type of installation (floor and wall), but all are characterized by increased corrosion resistance and a convenient control panel with LCD monitor. Outside, the heat exchanger is coated with a layer of aluminum anti-corrosion composition, an ionization electrode is located inside to protect it from electro-chemical processes. Almost all models have electric ignition, two control microprocessors, protection against blocking the pump, etc. The cost of gas double-circuit boilers Ferroli varies in a fairly wide range: from $ 1,200 to $ 3,000.

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

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

• 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 for boiler operation. 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 indoor and outdoor temperature sensors.

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

In order for the gas boiler to work without interruptions for many years, you need to choose a good UPS. Read about it in our next article:https://aquatech.tomathouse.com/en/otoplenie/kotelnaya/ibp-dlya-gazovogo-kotla.html.

Cast iron gas floor 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 in which an automatic three-way valve is built in. As a result, savings will be minimal. Good opportunities for reducing heating costs are provided by condensing models that use the energy generated by steam condensation.