Double-circuit gas boiler: operating principle, instruction and diagram

Double boilers today are the mostin demand in the market. Due to many factors. The most important of these is that a device with two circuits performs several functions. Let's take a closer look at what a double-circuit gas boiler is. The principle of operation of the device, as well as the wiring diagram and operating instructions will also be affected. This article is suitable for those who want to deal with this issue in more detail.

Some general information

Dual-circuit gas boiler, principle of operationwhich we now consider, can cope with two tasks at once: first, it is heating and maintaining the desired water temperature for the heating system, secondly, heating the carrier for economic use. Thus, your home is not only warm, but there is hot water. This is a significant difference between the double-circuit boiler from any other. You can make a simple conclusion that the design has two high-performance heat exchangers, each of which performs its function. In addition, the gas boiler can be of different power. Today on the market there are models from 12 to 35 kW. This is quite enough for heating a large room of 350-400 square meters. The performance of most models ranges from 8-12 liters per minute.

About the advantages of double-boiler

It is safe to say that meritsThese units have much more than disadvantages. Now we consider all the advantages. First, it is a significant gas savings. This was achieved through the use of modern heat exchangers. By the way, the hydraulic system made it possible to make the work of the units completely silent, so the dual-use gas boiler can be installed in any convenient place. Dimensions in most cases allow installation without any problems. If the floor option is not suitable, then it is always possible to install the device on the wall, which is especially important for small apartments, where every square meter is important. The operation of the double-circuit boiler is completely autonomous, which is facilitated by appropriate equipment (pump, expansion tank, computer and security system).

A little bit about cons

Nothing lasts forever, nor is it perfect.Double-boiler has several drawbacks. First, it should be noted, a noticeable loss of water at the initial stage. Consider a specific example. Here you have turned on the hot water, automatically earned additional coolant. To hot water went, you need to wait about 30-40 seconds, depending on the brand of the boiler. Everything that comes from a crane before this time is called a loss. It can be said with great certainty that this is not such a big drawback. If it is necessary to heat the carrier for economic purposes, then the dual-gas gas boiler does this in flow-through mode without the possibility of accumulation. Let's go ahead and talk about how the unit works.

Dual-circuit gas boiler: principle of operation

As noted above, the device can workin several modes. If a single-circuit boiler is intended only for heating the room, the 2-circuit can also heat the water, but this has already been said. If you need to heat the room, then the principle of operation is as follows: the carrier, in our case it is water, enters the heat exchanger, which heats it to a certain temperature. Today, the range hovers around 35-85 degrees Celsius. The thermostat starts the heating mode automatically. This is done when the temperature in the system falls below normal. As a result, the circulation pump starts up and supplies water from the heat exchanger (preheated) to the system. The pressure in the system is also taken into account, which should not fall below 0.5-0.7 Bar. If necessary, the microprocessor sends a signal to the burner, which heats the media to the desired temperature.

The principle of operation of the boiler: part 2

But this does not end there.After switching on, the boiler starts to work incrementally. First, at minimum power, and eventually reaches its maximum. When the gas wall-mounted dual-boiler heats the carrier to a predetermined temperature at some stage, the unit goes into modulation mode. If, on first power up, the power exceeds the allowable one, the microprocessor sends a signal to turn off the burner. Re-activation is carried out in three minutes. The combustion chamber is metal and has a special heat-resistant winding. Above it is a heat exchanger, under it a burner. The latter ignites exactly at the moment when the temperature of the carrier in the system drops and the water needs to be heated. Together with it, the circulation pump is also put into operation, designed to drive water through a closed system. When the set temperature is reached, the gas wall double boiler switches to the standby mode. In some models, the burner burns, but at a minimum, in others it goes out and lights up when the gas is supplied.

A little more about the features of the work

To prevent media from getting into the secondcircuit, use a three-way valve. Thus, it was possible to achieve the supply of heated water from the boiler to the system through one line (supply) and return through the other (reverse). It is worth paying attention to the fact that the double wall gas boiler is arranged in such a way that the carrier moves in a circle without forming a coating. But this concerns the first heat exchanger. In the second, water is taken from the pipeline. As practice shows, the quality of the carrier often leaves much to be desired. For this simple reason, it makes sense to install filters in front of the carrier that will remove insoluble compounds. If the hot water circuit breaks, the boiler can work in the mode of space heating. Thus, you will not sit in the winter in a cold apartment or house.

How the hot water system works (hot water supply)

If you switch gas heating boilerswall bypass in summer mode, then only the system for heating the carrier for domestic needs will function. In fact, the batteries will be cold, and hot water will flow from the tap. The principle of work here is very simple. The three-way valve changes its position and closes the heating line, thereby opening the way to the secondary heat exchanger, where the carrier goes. When water passes through the carrier, it heats up and goes straight into the hot water circuit. The process begins with the start of the relay, the contacts of which close when the flow rate of the carrier is more than 2.5 liters. A microprocessor command is issued to start the burner, and then the gas valve gradually opens. Power increases incrementally. Then the device goes into a smooth temperature control mode. It is worth noting that the gas wall-mounted heating boilers from all manufacturers are arranged so that the burner turns off when the temperature exceeds a predetermined temperature by 5 degrees and turns on when the temperature of the carrier decreases by 1 degree.

Double-circuit turbocharged gas boiler: advantages and disadvantages

The essence of the work of turbocharged models lies inthat there is forced ventilation. The air supply for the process of gas combustion, as well as the removal of combustion products is carried out using an integrated fan. In this case there is a pair of ducts of small diameter. The process takes place simultaneously. The products of combustion are released into the environment, and the oxygen necessary for maintaining combustion, on the contrary, is supplied to the boiler. Fans are mounted inside the boiler. But you should pay your attention that the forced tap is suitable for units with a capacity of not more than 30 kW. As for the benefits, they are obvious, there is no need to build a chimney. On the street are two pipes, one of large diameter, the second small. The first is used to supply oxygen, the second - for removal of combustion products. But there are also disadvantages here, the fact is that dual-circuit gas heating boilers have a more complex structure, and it is not always possible to make a hole in the wall. Let's look at another important point.

User's manual

It's hard to give specific recommendationsThis is due to the fact that each manufacturer has its own recommendations. But there are a few general rules that must be followed for the normal operation of your boiler. First, there is a special filter between the pipeline and the heat exchanger. So, periodically it needs to be cleaned or changed. How often do this, find out in your passport. Another requirement is to monitor the pressure in the system. In most cases, it should not fall below 0.5-0.75 Bar. If the figure is lower, it is necessary to add water to the system; if it is higher, then on the contrary, to lower a certain amount of carrier. Often there are two valves, as well as a pressure gauge, indicating pressure. If the arrow is in the green zone, then everything is fine. There is one trick, which is to reduce the amount of scale in the system. It is to not raise the temperature of the carrier above 45 degrees Celsius. With the increase occurs the decomposition of salts and other elements that form a dense plaque.

Scheme of double boiler

Let's talk about how to connectdevice. Often professionals are engaged in this, but if you decide to do it yourself, then without certain knowledge nothing will come of it. Firstly, a double-circuit gas boiler, the principle of operation of which we have already considered, must provide for a mechanical filter at the inlet. It is advisable to pre-install the shut-off valve on the return pipe of the boiler. This is done so that it is not necessary to air the system when the unit breaks down. After that, the boiler is mounted directly, further communications are supplied, that is, water supply, gas, and also coaxial pipes are installed for removal of combustion products and oxygen supply. In any case, the launch of the system is carried out under the control of the gas service. Do not forget that the gas boiler by-pass floor or wall must be set strictly to the level.

Conclusion

If you are going to install it yourselfdevice, then you definitely need a scheme of a double-circuit gas boiler. Often, it makes sense to pay and entrust this business to professionals. This is due to the fact that you will be dealing with an explosive gas, so any leakage can lead to serious consequences. Here, in principle, and all on this topic. Now you know how the double-circuit gas boiler works. The operating instructions are required to read, because you are dealing with serious equipment. Moreover, if you do not read the relevant documentation, you may not know many important points and "fail" the warranty on the device, as a result of which you will have to spend your own money if there is a breakdown.