How the thermostat works on the radiator

The amount of heat transfer medium varies as the air temperature in the heated room does. The regulating spool is activated concurrently with a change in the bellows’ volume. Variations in the room temperature have a direct impact on the spool’s movement. The regulator’s valve stem is activated by the sensing element in response to temperature changes. Consequently, the coolant supply to the heating device is regulated by the change in stroke.

For radiators of the mechanical type, the thermostat needs to be mounted on the supply line. The thermostat’s head needs to be horizontal and shielded from heat sources like direct sunlight. An insensitive zone forms around a valve that is covered by furniture or a curtain. This means that the thermostat is not in contact with the surrounding temperature and cannot perform its intended functions.

Special sensors with an overhead sensing element are used for remote control if there is no other way to locate this device.

Electronic thermoregulators

An automatic regulation device known as an electronic heating temperature regulator maintains the predetermined temperature range in a variety of heating apparatuses.

It performs automatic control of the boiler and the remaining actuators (mixers, pumps, valves, etc.) in the heating system. The primary function of the electronic thermostat is to establish a user-specified temperature regime in the space.

Principle of operation

The temperature sensor that comes with the electronic heating temperature regulator is placed in a location that is not directly affected by heating appliances. It gives the regulator data regarding the room’s temperature. The electronic device regulates the heating system’s components based on the data it receives.

Differentiate between analog and digital thermorelays that regulate temperature. Because of their usefulness, the former are the most commonly used. Temperature regulators of the electronic variety exist:

Closed logic.
Open logic.

Closed logic has a rigid internal structure and a constant algorithm that operates in time without being affected by changes in the environment. You can only modify a subset of the programmable parameters.

An open logic thermostat is a freely programmable device with many different settings and functions that can be adjusted for any type of operation or environment.

These devices are less common than those that use closed logic. This is explained by the fact that they need a specific level of qualification to operate. As a result, not all regular people are able to comprehend the settings and modes of electronic thermoregulators. Although open logic has been applied extensively in the industrial sector, it has the potential to become a necessary component of daily life for everyone.

Installing the thermostat on the radiator

It’s crucial to follow the installation instructions and avoid positioning these kinds of devices in niches or behind curtains or ornate grilles. A remote sensor is installed in the event that this is not feasible for any reason.

Cast iron batteries take a very long time to heat up and cool down, so installing a thermostat is inefficient.

It is essential to disconnect the riser and remove the coolant from the heating system before installing thermoregulators.

The installation of this device can then begin. It is advised that you follow this order of operation:

The horizontal pipelines are cut off at a certain distance from the heating device.
The cut-off pipe and the shut-off device are disconnected.
The nuts and shanks are disconnected together with the nuts of the valve or faucet.
Shanks are screwed into the radiator plugs.
The piping is installed at the selected location.
The piping is connected to the horizontal pipelines.

Here’s how to adjust a thermostat that has a temperature control:

All windows and doors in the room are tightly closed to minimize heat leakage.
A room thermometer must be installed in the room where a certain temperature is to be maintained.
The valve is fully opened by turning the thermostat head fully to the left, in this case the radiator will function with maximum heat output and the room temperature will start to rise.
As soon as the temperature is 5-6 °C above the initial temperature, the valve must be closed by turning the valve head to the right as far as it will go, after which the air in the room will gradually cool down.
After the temperature reaches the desired value, the valve is slowly opened by turning the regulator head to the left side. It is necessary to listen carefully, as soon as you hear the noise of water and feel a sharp heating of the thermo regulator body, stop turning the head and memorize its position.
The setting is complete. The room temperature will be kept to within 1 °C.

Thermoregulators on electric radiators

Given the state of public utility work today, many people turn to electric heating devices during the colder months when the temperature in their apartments isn’t always at the ideal level for comfort. They can serve as the primary source of heat as well as an auxiliary one.

Nowadays, a lot of manufacturers typically make electric radiators with thermostats, letting you customize the temperature in each room. Electric radiators are a great addition to central heating and a practical substitute.

How to choose and install thermostats on heating radiators

The thermostat for the battery, also known as the radiator valve or thermostatic valve, is a shining example of the control valve used in heating systems. Similar to other heating innovations, it arrived from Europe and was quickly incorporated into state building codes as a necessary component of any water heating system. Thus, the goal of this post is to explain the basic workings of a thermostat and provide users with guidance on how to choose, install, and modify one for their home’s heating system.

Why do you need a thermostat

Thermostatic valves that are carefully chosen and installed not only save energy but also make life much easier for homeowners by controlling the temperature in each room. After all, you can adjust the coolant temperature in each room simultaneously by using heating boilers to adjust each room’s temperature. However, the ability to adjust the temperature of the rooms based on their intended use is provided by the regulators of the heating batteries, which results in significant energy carrier savings.

As a point of reference. You can connect a remote heating thermostat to the majority of modern boilers to enable automatic heating control. However, this does not address the problem because all rooms will still receive the same amount of coolant at a given temperature.

The thermostatic valve’s job is to automatically maintain the room’s air temperature at the level that the user has set by controlling the amount of coolant that flows into the radiator based on that temperature. The radiator thermostat can only lower the flow rate of heated water; it cannot raise it. Therefore, it is crucial to have an adequate supply of heated water coming from the side of the heat generator.

Watch the following video to learn more about radiator thermovalves’ purpose:

An easy-to-use yet essential tool for effectively regulating the temperature in your house is a thermostat mounted on a radiator. It maintains a predetermined level of comfort by automatically adjusting the hot water flow through the radiator based on the temperature of the air in the room. The thermostat lowers the heat output by closing the valve when the room reaches the desired temperature; if the room cools down, the valve reopens to allow in more heat. Thermostatic radiator valves are an environmentally friendly option for temperature control in your home because of their automated process, which not only maintains your living area comfortable but also lowers energy costs by cutting down on needless heating.

Device and principle of operation of the thermostat

Every automatic radiator valve has two components:

Thermostatic valve with actuator for shutting off the flow of thermal fluid.
Thermostatic head with a control element that reacts to changes in air temperature.

The brass valve features a conventional mechanism wherein a functioning cone enters the seat, thereby decreasing its passage section. A spring-loaded push rod that extends outwards connects the cone, setting it apart from a traditional manual valve. The second component, the heat head, is responsible for applying pressure to the stem’s end. The cross-sectional area of the passage decreases with increasing pressure. The device of the heating battery assembly’s radiator regulator is depicted in the diagram below:

A tiny, hermetically sealed container containing a liquid or gas that is temperature-sensitive is located inside the thermostatic head. This medium expands when heated, growing larger and pressing harder on the stem to stop the thermal fluid from flowing. The thermal head functions on the principle that the process moves in the opposite direction when cooling. The valve’s maximum opening is mechanically limited by an adjustment knob featuring a scale.

Vital. Only the coolant flow rate is impacted by the thermostat mounted on the radiator; it can vary in either direction. The thermostat only regulates the water’s temperature quantitatively; it cannot regulate the temperature qualitatively.

Varieties and selection of thermostats

Based on their design, radiator valves are categorized into three groups:

straight;
Angled;
as part of the heater connection set.

If everything is evident when using straight and angular thermoregulators, then a separate discussion of the headset is necessary. It enables you to connect a thermostat to the pipes that emerge straight from the floor and install it on the radiator at the same time. This type of set will cost more than standard pipe connections, but it will have a much nicer appearance.

Headset for connecting radiators with built-in thermostat

Any of the aforementioned valves will work for two-pipe systems with a heating circulation pump; the only difference between them technically is how the heater is connected. Additionally, a single-pipe scheme is preferable because it allows you to purchase a unique battery temperature regulator with a wider seat cross-section. This type of thermoregulator has less hydraulic resistance, as the diagram makes evident:

For batteries, thermal heads must be chosen in addition to valves. A quick tip is that the head and the valve should come from the same manufacturer and have matching mating threads. The valve has M28 and M30 standard threads. The selection of head designs is generally limited to items with an electronic control unit and display in addition to the standard components with a built-in bellows. Because these thermostats are programmable, you can configure them to keep the room at various temperatures throughout the day.

Advice: Keep in mind that a programmable thermostatic head requires either a mains or battery power source to operate. The power supply needs to be watched over in order for the thermostat to function properly.

Conventional thermocouples might not work properly if heating devices are intended to be installed behind screens or if the room’s windows are going to be covered with heavy curtains. It is worth purchasing a remote sensor with a capillary tube in addition to the thermostat because the temperature behind and in front of the screen may vary by a few degrees due to the weak air movement in the radiator’s vicinity.

Through the use of a capillary tube, the sensor located behind the screen will regulate the thermostat and set it to the proper room temperature. A more sophisticated variation exists as well; it takes the shape of a remote regulator that is linked to the capillary tube. However, in this case, caution is required because not all valves, such as thermal heads, are appropriate. As such, you should speak with the seller before selecting a thermostat.

Lastly, a few remarks regarding radiator valve manufacturers. They made frequent appearances, particularly the Chinese, whose credibility is seriously questioned. It is highly recommended that you use the thermoregulators from the following brands; their dependability is proven:

Advice: You don’t have to purchase and install thermostats on every radiator in your home. The rule states that only radiators in each room whose total capacity is 50% of the total or more should have thermostatic regulators installed in order to ensure appropriate regulation. To put it simply, the valve should be placed on the larger of the two heaters in a room, on the second radiator if there are three, and so forth.

Installation and adjustment

Make sure your heater does not come with a valve installed from the factory before purchasing and installing a thermostat on the radiator. This is relevant to steel panel radiators made by certain producers, like HEIMEIER or KERMI. The thermostatic head itself only needs to be purchased with the right thread and inserted into the right socket.

You shouldn’t have any trouble installing the thermostat on the batteries and adjusting it with your hands. The following suggestions are provided:

The valve is always installed on the supply pipe only.
Observe the flow direction indicated in the product data sheet.
When installing, use Americanized fittings so that the assembly can always be disassembled.
The position of the valve and head as well as the distances to the nearest structures are shown in the diagram:

In order to service the radiator, an extra ball valve needs to be installed upstream of the thermostat if it lacks a mechanical blocking feature, as seen in the diagram:

Mounting the thermo-head

There are two methods for attaching the element to the valve body: threading or, in the case of DANFOSS products, simple snapping. In any event, you should unscrew the valve box’s protective cap before turning the head handle to the "max" position and inserting it into the socket until it clicks, or, if the connection is threaded, slightly tightening it with a wrench. The thermostat is successfully installed if its head rotates normally.

Certain manufacturers’ valves and every head have a presetting feature. This is a temperature control range advance limitation, which varies depending on the model. Certain products, like the HERZ ARMATUREN thermostat, are restricted by unique pins, while other items come with a key that fixes the head in a specific position.

The battery thermostat’s operational adjustment is done using a handle that has numbers and a scale (designations). The smooth adjustment range is typically 16–28 °C. When the valve is in the "*" position, it will keep the air temperature at 6-7 °C to prevent defrosting.

Finally, a few remarks regarding thermostat compatibility with cast iron heating appliances. Although there are concerns regarding thermostat effectiveness, installing one is not inherently prohibited. Due to their size and water capacity, cast iron radiators are inertial and will react slowly to automatic regulation. Therefore, it is best to install a balancing valve on the return and an ordinary valve on the supply in this situation.

How to choose a thermostat for heating radiators

Up to 40% of energy resources in post-Soviet nations are used for building heating and ventilation, which is significantly more than in developed European nations. The need to conserve energy is more important than ever, particularly in light of the steadily rising cost of energy sources. A thermostatic controller for batteries is one of the gadgets that lets you save thermal energy in the house; with its installation, you can cut your heat usage by as much as 20%. However, in order to achieve this, it is essential to install the heating system’s regulators correctly, which will be covered in this article.

Principle of operation of the thermostatic valve

The DANFOSS company, which leads the industry in the manufacture and distribution of these devices, created the first radiator thermostats in 1943 with the goal of keeping the room’s temperature constant. Because of this, the information in our piece will come from the company DANFOSS, whose many years of experience speaks for itself.

Radiator thermoregulators have evolved over time to become what we know them to be since their invention. They are made up of two primary structural components: the thermal head and the valve, which are fastened together by a fastening mechanism. The thermal head’s function is to sense the surrounding air temperature and control it by operating the valve, which stops the coolant from entering the heater.

Since the device modifies the coolant flow rate into the radiator, this regulation technique is known as quantitative. Another approach is qualitative, which is used to alter the system’s water’s temperature. The temperature controller, also known as the mixing unit, is what operates in the heating station or boiler room.

It is advised that you examine the device’s diagram, which is shown in section: to comprehend the fundamentals of the thermal head’s operation.

There is a bellows containing a temperature-sensitive medium inside the element’s body. There are two varieties available:

Gas bellows have gained a lot of popularity because they are faster than liquid bellows, which are more difficult to make. As a result, as the temperature of the surrounding air rises, the material within the enclosed space expands, stretching and pressing on the valve stem. The valve’s cross section is subsequently decreased as a result of this moving down a unique cone. The coolant flow rate is lowered as a result. The thermoregulator operates on the principle that everything happens in reverse order when cooling the ambient air, increasing the amount of water flowing to a maximum.

Selection recommendations

The flow of the heating medium can be controlled by a variety of valve-thermal head set combinations, depending on the type of heating system and the installation circumstances of the device. It is advised to install valves with low hydraulic resistance and increased flow capacity in single-pipe heating systems (DANFOSS product markings: RA-G, RA-KE, and RA-KEW).

For two-pipe gravity-flow systems, in which the coolant circulates naturally without the need for forced induction, the same advice is applicable. A valve with the option to adjust the flow capacity should be chosen if the heating scheme is a two-pipe system with a circulation pump (DANFOSS marking – RA-N, RA-K, RA-KW). There is no special tool required for this adjustment because it is very easy to make.

Once the valve selection issue has been resolved, the type of thermal head needs to be chosen. The following versions are available for them:

With internal thermocouple (as in the diagram above).
With remote temperature sensor.
With external regulator.
Electronic (programmable).
Vandal resistant.

If the axis of a conventional thermostat for radiators with an internal sensor can be positioned horizontally to allow room air to freely wash the device’s body, as depicted in the figure, the thermostat may be installed.

Take note! Installing the thermo regulator vertically on the radiator is not permitted because the heat flow from the supply pipe and the valve body will affect the bellows, which will cause the device to malfunction.

If the head cannot be mounted horizontally, it is preferable to buy a remote temperature sensor that comes with a 2-meter capillary tube. You can position this device and mount it to the wall at this distance from the radiator:

There are other valid reasons to buy a remote sensor besides vertical installation:

Heating radiators with temperature regulator are located behind thick curtains;
there are hot water pipes or another heat source in the immediate vicinity of the thermal head;
the radiator is located under a wide window sill;
The internal thermocouple enters the draught zone.

Radiators are frequently concealed beneath ornate screens made of a variety of materials in spaces with high interior requirements. In these situations, the heat transfer medium can be totally stopped by the thermo-regulator, which has fallen beneath the cover and senses the temperature of hot air building up in the upper zone. Furthermore, there is total blockage to the head’s control. In this case, selecting a remote controller in conjunction with a sensor makes sense. The following are examples of how it could be placed:

There are two varieties of electronic thermostats with displays: ones with an integrated control unit and ones with a detachable one. The latter is distinguished by the electronic unit’s ability to function normally even after it is disconnected from the thermal head. These devices are meant to control the room’s temperature based on the time of day and the program. This leads to additional energy savings by enabling the heating power to be lowered during working hours, when no one is home, and in other comparable situations.

Installing a vandal-proof thermoregulator with a cover that shields the device’s settings from inexperienced interference is preferable when there are young children in the house who want to try everything on their own. This also holds true for thermostats found in other public buildings, such as schools, hospitals, and daycare centers.

It is essential to comprehend how a radiator thermostat operates in order to properly control home heating. With the ability to regulate the temperature in every room, these devices help you save energy while maintaining comfort. The thermostat maintains a constant temperature by automatically adjusting the hot water flow through the radiator based on the temperature you set.

The capacity of radiator thermostats to increase the efficiency of your heating system is what makes them so attractive. They function by detecting the temperature of the air around them and controlling the radiator’s heat output. This prevents energy and heat waste in addition to maintaining a comfortable temperature in your living area. As a result, you can have a comfortable home without having to pay a lot for energy.

Moreover, with programmable and intelligent features, contemporary radiator thermostats provide even more flexibility and accuracy. With these cutting-edge thermostats, you can remotely control them using a smartphone app or schedule heating times based on your daily schedule. With the help of this technology, you can heat your house more efficiently and make sure that it’s never left unattended by adjusting to unforeseen changes in your schedule.

In conclusion, you can greatly improve the comfort and effectiveness of your home heating system by installing and using radiator thermostats correctly. Despite their apparent simplicity, these gadgets are essential for energy conservation and for preserving the proper temperature in the house. It is well worth it to take into account how new or upgraded thermostats will affect both your comfort and your pocketbook.

How the thermostat works on the radiator

Thermostat on the radiator: principle of operation, setting, installation

Mechanical thermostat

Constituent elements

Influencing factors