The complete set of any heating system must include regulation devices. Without them, the work of heat supply will be ineffective, which will lead to an increase in operating costs. One of the most popular devices is the thermostat for the heating system: the principle of operation, installation, the device must be known to draw up a competent scheme.
Purpose of thermostats for heat supply
First of all, you should decide on the purpose of these devices. The fundamental principle of operation of a heating thermostat is to restrict the flow of coolant to a specific section of the system - a pipeline, radiator or battery.
Despite the fact that a programmable thermostat for a heating system differs from a mechanical analogue - to perform its functions, both apply the principle of changing the flow diameter of the pipe. For this, a flap or a needle valve is used. The function of regulating the position of these components is performed by a control element. It can be either mechanical or electronic.
By installing a thermostat for a radiator or a similar device for a boiler or collector, you can achieve the following improvements in the operation of heat supply:
- The ability to adjust the flow of coolant into the battery or heating circuit... Thus, you can control the degree of air heating in each room of the house;
- Cost optimization... If you install them in all critical areas of the system, you can achieve savings of 25-30%;
- Work automation... This is especially true for innovative heating methods. It is mandatory to install a thermostat for air heating on each damper to control the flow of hot air.
However, there are certain restrictions on the use of these devices. Experts do not recommend using a thermostat for a heating boiler, as it will limit the flow of coolant for the entire system. It is best to install multiple instruments on the battery, pump and manifold.
Each thermostat for heating radiators has a capacity parameter. It depends on the diameter of the connecting pipe. In the open state, the thermostat should not restrict the flow of the coolant, creating excessive hydraulic resistance.
Types of heating thermostats
At the first stage, it is necessary to calculate the main characteristics of the system. Then, based on the data obtained, a layout of the control devices is drawn up. So, a thermostat for a two-pipe heating system is mounted on radiators. In addition, installation on tee branches is possible.
Can a thermostat for central heating differ from a similar one for autonomous heating? There is no difference in the models. The choice is determined only by the parameters of the device and design features. Therefore, before purchasing, you need to solve the following tasks for yourself:
- Place of installation of the device... Thermostats for heating pumps are structurally and functionally different from those for batteries. They have a large degree of adjustment, as well as the ability to connect to a pump control unit;
- Required functionality - work in automatic, manual or semi-automatic mode;
- Adaptation to the overall heating control system... For this, the heating thermostat device must have pluggable terminals for connection to a central programmer or similar device.
Manufacturers currently offer several types of thermostats. They differ not only in appearance, but also in design and functional features. Let's consider the most common types of these heating control devices.
Before purchasing a thermostat for a radiator, it is recommended that you read the connection instructions. Not all models are designed for installation in cast iron or bimetallic radiator piping.
Mechanical heating thermostats
To complete the budgetary heat supply system, the best option would be to install mechanical models of thermostats. They are distinguished by their simplicity of design and easy installation. However, along with these qualities, mechanical thermostats for hot water heating have several features of installation and operation.
Structurally, this device consists of a locking mechanism (needle valve) and a thermal head. In the latter, a sensitive element is located, which expands under the influence of high temperature. It presses on the valve seat, which leads to a partial or complete shutdown of the coolant flow. To set the upper and lower limits of the thermostat response for heating radiators, a spring is provided in the design, which connects the thermostatic element and the control head. The operating conditions of the device depend on the set compression ratio.
Features of the operation of mechanical thermostats are as follows:
- Full autonomy of work... The device does not need to be connected to the mains;
- Semi-automatic operating mode... It is enough to set the temperature of operation of the thermostat for central heating once;
- Affordable cost... The price of budget models ranges from 200 to 400 rubles.
The disadvantages include frequent breakdowns. This applies in particular to the operation of the thermostatic element. Over time, the fluid loses its properties, which leads to improper functioning. After long periods of inactivity, limescale deposits can form between the valve seat and the thermostatic element. This is the reason for the failure of the thermostat for a two-pipe heating system.
During installation, the thermostatic head must be positioned horizontally. Otherwise, hot air from the battery will be exposed to it.
Electric heating thermostats
They are designed to operate heating devices powered by electricity. The simplest thermostat for electric heating is an on / off relay that is activated depending on the readings of a temperature sensor.
Such devices are part of electric heaters and perform an important function. Without them, the heating element will work constantly, which will not only lead to a significant increase in temperature, but will increase the cost of electricity. In this case, the installation of the thermostat on the heating radiator is performed at the factory. But there are options for the independent manufacture of this device and its installation in an electric heater.
Features of the work and operation of electrical thermostats:
- Automatic control of the degree of heating of the device and turning off the electric heating element when the optimum temperature is reached. For this, a thermal sensor is built into the design;
- Ensuring work safety;
- Some models may have a programmable thermostat for the heating system. After specifying the operating modes, it is possible to achieve automatic operation of the device depending on the time of day, the temperature outside and indoors.
Thermostats for air heating work on a similar principle. But they control the position of the hot air damper.
To connect an electric heater, it is recommended to allocate a separate power line connected directly to the central distribution board.
Electronic thermostats for heating
These are sophisticated heating control devices, the operation of which is carried out using a microprocessor. It connects to external temperature sensors and has a flexible software package.
The difference between this device, electric thermostats for electric heating and mechanical models is much more functionality. Depending on the type of device, it may have terminals for connecting external devices, as well as connecting with other control components. In particular, with a programmer.
Almost all electronic thermostats for heating differ in the ability to control heat supply. Some have only a built-in temperature sensor and a mechanical part that is responsible for the volume of the coolant inflow. But most often, buyers stop at models with significantly greater capabilities:
- Remote control. For this, an IR port is provided in the electronic thermostat for a heating boiler or radiator, through which control signals are received;
- The ability to independently set a program of action depending on external conditions. Programmable thermostats for heating systems are convenient when you are not constantly in the house. You can configure the device so that it starts heating at a specific time or by command from the GPS module;
- The mode of maintaining the minimum temperature of the heating medium in order to provide freezing of water in the pipes. This feature will save costs.
Otherwise, the principle of operation of the electronic heating thermostat remains the same - changing the position of the valve (needle valve) using a control element.
Not every model can be connected to other devices. Some thermostats for heating pumps do not have external connection elements. This should be checked before purchasing.
Installation of thermostats in the heating system
Before proceeding with the installation of control devices, it is necessary to check - are they suitable for this heating system? In some cases, you should first carry out a small upgrade, and only then proceed with the installation.
The basic principle of the correct installation of the thermostat on the heating radiator is that there is no effect of the operation of the device on the heat supply parameters. Those. after its installation, the throughput in this section of the circuit should not deteriorate, additional hydraulic resistance should arise, etc. This is especially true for a one-pipe system.
In this case, you need to do the following:
- On the site where it is planned to install a thermostat for a heating radiator, a bypass is made. This is a pipe connecting two sections of the line for the possibility of partial or complete redirection of the movement of the coolant bypassing the battery.
- Depending on the device of the heating thermostat, the place of its connection to the radiator, pump or collector is selected.
- The possibility of completely disconnecting a section of the highway from the system without interrupting circulation is being checked.
These are mandatory installation requirements that do not depend on the principles of operation of thermostats for hot water heating. For proper installation, it is necessary to consider the features of connecting control devices to each element of heat supply.
For normal heating operation, it is necessary to calculate the parameters of the system, taking into account the characteristics of thermostats for central heating or an autonomous analogue.
Installing a thermostat on a battery
Installation of a thermostat for water heating can be carried out both in the upper part of the battery and in the lower one. It all depends on how the device is connected to the system. After choosing the optimal model, you can proceed directly to the installation.
To do this, you need to follow simple rules:
- Consideration of the direction of movement of the coolant... This is important when installing thermostats for a two-pipe and one-pipe heat supply system. On the body of the control element, an arrow indicates the desired direction of movement of hot water;
- First, the mechanical part is mounted, and then the thermal head... Its position should be such that hot air from heating radiators does not affect the thermostat;
- The control element cannot be covered with a decorative panel... This can lead to overheating and false alarms.
Otherwise, experts recommend adhering to the recommendations for installing a thermostat on a heat supply radiator from the manufacturer.
After installation, it is necessary to check the operation of the device in several modes, up to full opening and closing of the damper.
Thermostats in heating collectors
In the underfloor heating system and collector heating, thermostats are an integral element. In this case, electronic models are used with the ability to connect to external temperature sensors.
In such schemes, it is important to choose the right device for controlling the flow of the coolant. Modern electronic thermostats for a water-heated floor are equipped with servo drives that can quite smoothly regulate the volume of the coolant inflow. However, for their correct installation, you will need to follow the following rules:
- The throughput of the device must not be less than that in the connected branch pipes;
- For normal operation, it is recommended to install an uninterruptible power supply unit, since during a power outage, the circuit will not function;
- Mandatory presence of a safety group in the collector piping. Excessive temperature or pressure can adversely affect the condition of the thermostat.
The best option is to purchase a fully equipped collector. All its elements will be coordinated with each other, which will provide the risk of malfunctions.
The installation of mechanical thermostats for a water-heated floor is not recommended, since their operation cannot ensure the normal functioning of the system.
Installation of thermostats for heating circulation pumps and boilers is extremely rare. This is due to the fact that after installation, the device will affect the speed of movement of the coolant. A small reduction in the passage on the line section is enough to create excessive hydraulic resistance.
To improve the operation of the thermostat, it is recommended to install it together with modern heating devices with low inertia - aluminum or bimetallic radiators.
The video shows an example of installing an electronic thermostat:
