Double-circuit boilers not only allow heating the dwelling, but also provide it with hot water. These universal devices are popular, due to their compact size and ease of use. Before using such equipment, you should familiarize yourself with its device, connection features, and basic connection diagrams.
Device
Double-circuit gas boilers have several elements in their composition, among which are:
- burner;
- circulation pump;
- combustion chamber;
- three-way valve;
- secondary heat exchanger;
- main heat exchanger;
- automatic appliances.
The burner is the main module of the heater. It is located in the combustion chamber. The main function is the heating of the coolant and the release of thermal energy for hot water supply. To maintain the desired temperature, this element has an automatic combustion control system.
What is a pump for?
The circulation pump is necessary to create a forced movement of water inside the pipe. This unit is also responsible for the efficiency of the hot water supply. When compared with a fan, the pump runs silently.
The burner is installed in the combustion chamber. It can be closed or open. It is supplemented by a fan that delivers air and fumes.
Thanks to a three-way valve, the boiler switches to the function of heating water for hot water supply. The secondary heat exchanger is responsible for heating the water for hot water supply. The main one is located on top of the burner and is located inside the combustion chamber. This ensures that the water that enters the hot water system and heating pipes is heated.
What is automation for?
Control of the boiler operation parameters is provided by automatic devices. They are necessary to monitor the level of heating of the coolant. This allows you to adjust the operation of the burner. Automatic devices help to manage different nodes, they fix problems that arise and support the flame.
In the lower part of the housing there is a space for the removal of communications of the heating circuit, cold pipeline and gas supply. A number of modifications of gas boilers is supplemented by twin heat exchangers, while the operation of the double-circuit boiler remains the same.
Wiring diagram
The connection scheme for a dual-circuit floor gas boiler is quite simple. You need to understand that such equipment is reliable, so for the entire period of operation it is unlikely there will be a need for its shutdown and repair. From this we can conclude that the overhead taps are installed first. They are necessary for the maintenance of the heating system. It is hardly necessary to dismantle and cut off the heat generator.
How to expand the scheme
Having familiarized yourself with the technical data sheet of the product, you can see which system is used for connecting double-circuit gas boilers. The scheme can be expanded by increasing the number of potential consumers.
1/2 ”taps are mounted on fittings for gas, hot and cold water. 3/4 inch valves are installed on the nozzle with coolant. To feed and empty the system, you need a third tap. The fittings are set down by the Americans. At the entrance from the heating network and the water supply system there must be mud collectors, they are placed in a horizontal position so that the cleaning is convenient. The nose should face down.
Tank connection
Using the described scheme for connecting a gas double-circuit boiler, you will need to connect an external expansion tank to the return pipe. For this, additional fittings are used, which will empty and cut off the containers. The make-up and drain pipe is installed at the bottom of the system. If the boiler is to be wall mounted, then the valves must be screwed up before hanging the equipment on the wall. When the handles or butterfly interfere with rotation, they should be removed by unscrewing the nut on the stem. The gas supply valve is installed through a dielectric gasket.
When antifreeze is used
If you fill in a non-freezing coolant in the system and want to play it safe, it is better to use an alternative scheme for connecting a gas double-circuit boiler.
On the "return" and "feed" are two cranes that will allow you to dismantle the boiler and carry out system maintenance without draining the antifreeze. Such a scheme can be used for two- or three-story houses, where there are water heated floors and a radiator network. No additional expansion tank is indispensable here.
Mains connection diagram
The rules for connecting electricity are very simple. You will need line protection, and for this, grounding and a circuit breaker are used. If the furnace does not have powerful equipment like an electric boiler, then there is no need to run a separate cable to the distribution panel.
Considering the scheme of connecting a gas double-circuit boiler to electricity, you should pay attention to the switch. It should be located in a safe place where water or coolant will not get in the event of a rush. It is important to ensure that there is a wire that will be connected to the ground loop. If the cord in the equipment set does not have a third core, the conductor should be connected to the steel body of the heat generator. The use of metal pipes is not recommended if you consider them as grounding conductors. Cables should be laid in a corrugated protective sleeve.
Studying the connection scheme of a gas double-circuit boiler, you must consider that European turbocharged equipment is sensitive to the features of the phase connection. If you mix the phase and neutral wires, the electronic control unit will not start the device. If the house is located in an area with unstable mains voltage, it is recommended to power the boiler through a stabilizer that protects the electronics from burning out. If interruptions often occur in the power supply system, it is best to purchase and install an uninterruptible power supply unit, otherwise the house may be left without heat when it is turned off.
Installation Features
Double-circuit heat generators operating on natural gas can be divided into two subspecies. Such devices are non-volatile and require power. The second should be connected to electricity and heating in the same way as the wall types. Non-volatile floor units heat water for hot water with a copper coil or with what is made of stainless steel. It is integrated in the main heat exchanger. The complete set of the heater is minimal, there are:
- heat exchanger;
- security automation;
- burner.
For installation in this case, you need to purchase:
- security group;
- circulation pump;
- expansion tank.
The safety group must have a safety valve, the working pressure of which corresponds to this indicator in the passport. When choosing an expansion tank, you should prefer one whose volume is 10% of the total amount of coolant. An open expansion tank will complement the connection circuit of a dual-circuit gas boiler. The installation system of this equipment does not imply a safety group and a pump. When choosing pipes, you must purchase those with a diameter of at least 40 mm. Their laying is carried out with a slope of 5 mm per 1 linear meter of the line. At the lowest point of the system is a heater. The open tank should be located at the highest point. If there is electricity, you can arrange forced circulation. The bypass pump is activated here.
Connection diagram with indirect heating boiler
Such a combination began to appear among those consumers who were not satisfied with the operation of the hot water supply circuit of the heat generator. This fact cannot be called surprising, because an average power device delivers about 10 liters of water per minute, this volume is not sufficient to provide two consumers, for example, a shower and a sink in the kitchen. The double-circuit gas boiler can be connected to heating in conjunction with an additionally purchased indirect heating boiler. In this case, a simulated flow is created by a circulation pump, which starts and stops by the thermostat signal. Such a scheme may not work correctly.
The heating unit delivers water with a maximum temperature of 60 ° C. It passes through the coil of the boiler, without heating its contents to the same temperature, because the volume can reach 200 liters. Water with a temperature of 55 ° C instead of cold enters the second circuit of the boiler from the heat exchanger of the boiler. It is heated by a burner, which is switched off by a sensor signal. Due to the duct, switching on occurs again after a few seconds, which reduces the resource of the heat generator. At the same time, the boiler heats up longer than the required time, which depends on the power. Heating remains turned off, because the unit is engaged in a hot water circuit, and the house cools down.
In the storage tank, bacteria multiply that live in warm water. It is removed by heating the boiler to a maximum temperature, but it is unrealistic to achieve this. When connecting a dual-circuit wall-mounted gas boiler, you must use the correct circuit. It will include loading an indirect heating boiler in 25 minutes. To do this, the hot water pipes are plugged, but this does not affect the resource of the heat generator.
Connecting a double-circuit gas boiler to the system necessarily means connecting the equipment to the gas, heating, water, heating return and piping. Lastly, the connection to the gas pipeline.
The connection of a double-circuit gas boiler to the heating system begins with the installation of a filter for rough cleaning, which prevents clogging of the device. This unit is put on the pipe nozzle.