A detailed overview of automation for gas heating boilers

Each gas heating system in a private house or city apartment has individual technical characteristics and features. Gas boilers differ not only in functionality and principle of operation, but also in the control system. For safety reasons, all models of gas boilers are equipped with devices and devices for automatic adjustment of heating equipment. To get a more complete picture of autonomous heating in the house, you should understand how the gas boiler automation system works, and what types of such devices exist.

The heating gas boiler is a complex engineering product that requires constant attention during operation. Automatic control is able to provide the necessary control of the parameters of the boiler, making the heating system truly autonomous.

What is automation for a gas boiler. General view

Automation used for gas boilers are special devices that provide control over the operation of heating equipment after it is started. The main purpose of automatic control devices is to ensure the safety of operation of heating units and maintain the optimum temperature in the room.

By functionality, automation is divided into two main types:

• volatile devices;
• non-volatile control devices.

The first type is volatile automation, used in autonomous heating systems, has a simpler design and works according to the residual principle. The signal from the temperature sensor about temperature changes is sent to the solenoid valve, which closes or opens, shutting off the gas supply to the gas boiler. Almost all heating boilers are equipped with this type of control equipment.

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The second type of automation non-volatile devices work on the basis of the physical properties of the substance inside the closed circuit of the device. When heated, the substance expands, creating increased pressure inside the device. Under the action of high pressure, a gas valve is actuated, shutting off the gas supply to the combustion chamber. The boiler is switched on in the reverse order. When the temperature decreases, the volume of the substance decreases, as a result of which the pressure in the device decreases. The valve returns to its normal position, allowing gas to enter the burner. Such automation devices are equipped with non-volatile gas boilers. Models of automation system blocks may differ only in the standard set of functions.

See also: Grounding a gas boiler: how to do it and why?

The principle of operation of automation. Main knots

Considering the internal structure of safety automation devices, we can make an unambiguous conclusion that the main structural elements are the safety and main valves that shut off the fuel supply to the working area or open gas access to the combustion chamber. All automation for gas heating boilers is built on this action. Differences can only be in the presence of additional functions for automatic adjustment devices and how to control them.

For example: You want to turn on the boiler. Ignition is carried out by supplying gas to the pilot burner. This process is controlled by a solenoid valve. The installed thermocouple, heated by the pilot burner, is capable of heating in a short period of time, only 2-3 s. give the necessary spark to ignite the gas on the main burner. Releasing the ignition button, you start the main valve, which supplies gas to the combustion chamber.

The device works due to the interaction of both valves.

Choosing the required air temperature for the heated room, set the regulator to the desired position. The whole process is clearly monitored by a thermostat, which is equipped with sensors that regulate the volume of gas entering the combustion chamber. Thanks to two valves, shut-off and modeling, installed in the thermostat, the gas flow is regulated, and therefore the heating intensity of the boiler. The layout of the main adjustment points on the devices approximately looks like this.

On a note: The heating intensity of boiler equipment can be adjusted by increasing or decreasing the operating pressure at the fittings. A conventional membrane is able to regulate the working pressure of the household gas at the outlet. In another situation, the outlet gas pressure in the system can be adjusted by manipulating the gas supply screw.

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It is necessary to dwell in more detail on what types of automation exist for domestic gaseous fuel boilers, on what principle the operation of automatic devices is based, and how this affects the safety and efficiency of an autonomous heating system.

Basic functions of automation

The main purpose of automation in heating systems is an instant response to a change in the situation. One of the main tasks of automatic control devices is to stop the gas supply to the working area. Situations in which it may be necessary to cut off the supply of domestic gas may be the following:

• poor operation of the exhaust device, deterioration of traction, in which there is a high probability of harmful combustion products entering the interior;
• sharp drops in operating pressure in the main gas pipeline;
• unauthorized extinction of the flame on the main burner.

In these situations, it is thanks to the automation of the gas boiler that the supply of gas fuel is controlled, which ensures the safety of residents. It is for safety reasons, in accordance with existing regulations, that it is necessary to equip all old models of gas-heating equipment with automatic systems, the standard equipment of which did not provide for the equipping of these devices. As for the gas heating units of the latest releases, these are boilers with automatic equipment.

For reference: in some cases, it is cheaper to install a new boiler than to upgrade the old heating system by equipping the boiler with automation. The reason lies in the significant design differences between the old-style models and modern heating units.

Main article: do-it-yourself gas burner

Which automation is better — mechanical or electronic?

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Devices that control the operation of heating equipment can be mechanical or electronic. In budget models of gas boilers, in most cases, a mechanical, manual control option is used. Despite the fact that the level of technological progress has reached unprecedented heights, mechanics remains a reliable and proven tool. Automatic safety of gas boilers, operating in manual control mode, is an order of magnitude cheaper. The principle of operation of most models of manual boilers is simple and understandable for domestic use.

The automation unit of the mechanical principle of operation is easier to maintain and repair. Dismantling such a unit is quite within the power of a specialist — a heat engineer who carries out a routine inspection of boiler equipment in your home.

Manual, mechanical control of a gas boiler, regardless of the power supply — the owner of the home independently sets the temperature necessary for heating the living space, everything else depends on the laws of physics that underlie the operation of the mechanism.

For reference: the heat exchanger is equipped with a thermocouple — a mechanism based on a plate combined from two parts — steel and nickel. During heating, the plate lengthens, and when cooled, it decreases in length, acting on the valve, which opens or closes the gas supply to the working area. The draft regulator, which is equipped with gas boilers with an open combustion chamber, also works on the basis of the same principle. Bimetallic plate when the temperature rises to a critical point (more than 75⁰C) bends, opening the circuit. When the flame decreases, the plate returns to its natural position. Everything is simple and clear.

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A different principle of operation is laid down in automation with electronic filling, which uses not the physical properties of materials and media, but a fundamentally different way of transmitting a signal to equipment.

Electronic automatic control systems

The most common type of automation that is used in budget models of boilers is an electronic thermostat.

The device is installed indoors and controls heating based on signals from a remote temperature sensor located in the actual zone of the room. When the temperature drops below the set limit, the boiler is signaled to turn on. When the optimum temperature parameters are reached, the sensors transmit a shutdown signal to the system. Room thermostats have a cable connection with gas boilers.

In this case, the presence of a thermostat ensures the optimal heating temperature of the gas boiler and the economy of blue fuel consumption. To date, several types of thermostats are on sale, differing in functionality, technical characteristics and installation method. Programmable devices ensure that the optimal temperature regime is maintained inside the dwelling for a given period of time.

On a note: some models can automatically control the operation of a gas boiler during the day, other models of equipment are able to control the operating unit during the week. Wireless automatic control devices are also produced, allowing remote control of the operation of the boiler. The range of modern remote control systems, depending on the model chosen, is 25-100 m.

Conclusion

What is better, mechanical automation or electronic control devices, the consumer decides. A good gas boiler can work successfully both with manual control and with the use of electronic automatic devices.

Modern appliances, which are equipped with all models of gas boilers that exist today, are an integral part of the heating system. Without appropriately configured automation, not a single gas boiler will work correctly.