Thermostatic valve is used for hot water systems. Most often it is used to regulate the temperature of water. It can serve cold, hot and warm water. In addition, a thermostatic valve is used for heating systems. With its help, the temperature of the coolant is controlled by mixing the flows of cold and hot water. It is especially advisable to arrange a thermostatic valve for a warm floor system, where the water should not be too hot.

Thermostatic valve for hot water and heating systems

Types of valves

By appointment:

• mixing - mixes two streams of water of different temperatures;
• separation - distributes into separate streams;
• switching - performs switching flows in different directions.

The operating principle of a thermostatic valve is shown schematically on its surface.

By regulation method:

1. With preliminary adjustment. Adjustment is made in advance, using a special key, by a qualified specialist.
2. With open adjustment. In such systems, you can adjust the operation of the equipment at any time.

By type of installation:

• straight;
• axial;
• angular;
• for right installation on a radiator;
• for left mounting on a radiator;
• three-way valve.

Direct thermostatic valve

By type of heating systems:

• for single pipe heating system;
• for a two-pipe heating system.

The thermostatic valve for a single pipe system has a larger connection diameter.

By type of substance in the device:

• gas;
• liquid;
• paraffin.

By type of thermocouple:

• manual regulation;
• thermal head - regulates the system in automatic mode;
• remote thermocouple - installed separately from the radiator.

Principle of operation

The thermostatic mixing valve mixes two streams of different temperatures into one. It has three moves, hot water is supplied through one, cold water through the other, and warm water is given out after the third, after mixing. If the fluid that moves in the hot stream has an acceptable temperature, then the cold stream is completely blocked.

If the temperature exceeds the limits, the valve gradually opens, due to which cold water is mixed and its temperature at the outlet is normalized. The hotter the water, the more constipation opens with a cold stream. A three-way thermostatic mixing valve is necessary to obtain a coolant of optimum temperature.

Three way thermostatic mixing valve

• 1 - a sensor with a thermostatic head, sets the required water temperature and provides it at the outlet, due to the adjustment of the degree of stem pressure.
• 2 - spring-loaded stem, regulates the operation of the valves.
• 3 - upper and lower poppet valves, designed to control flows.
• 4 - mixing zone, this is the chamber in which the mixing of flows takes place.

Pros and cons

Advantages of thermostatic valves:

• does not need special maintenance;
• compact sizes;
• aesthetic appearance;
• automatic adjustment of water temperature in the pipeline;
• providing a comfortable microclimate in the home;
• the ability to set the desired temperature in each individual room.

Disadvantages:

• the difficulty of setting up the device;
• failure of the thermostat can occur under the influence of a draft or a nearby stove;
• dependence on the supply of hot and cold water supply.

Balancing Valve Installation

Thermostatic balancing valve is designed for hydraulic adjustment of the heating system. It provides an even supply of water to all radiators. In addition, it is arranged on a small loop of solid fuel boilers, if it is closed on a buffer tank. With its help, the temperature in the circuit is kept at least 60 0 С, and there is no need to arrange a mixing unit. In such a scheme, the flow rate of the small circuit must exceed the flow rate of the heating circuit. This provides a valve installed on the feed.

Thermostatic balancing valves for hydraulic adjustment of heating systems

The best option would be to install a thermostatic balancing valve on each circuit, including underfloor heating and hot water.

Valve for underfloor heating

Small room

If the underfloor heating is arranged in the bathroom, hallway, kitchen or just in one room, it is inappropriate to install a mixing unit, because its cost will be too high. Alternatively, it is possible to install a kit specifically designed for underfloor heating. The set includes shut-off valves (two pieces) and a thermostatic valve.

The underfloor heating medium should not be too hot. To do this, the thermostat determines the temperature of its supply from the boiler and, if it exceeds the permissible limits, the valve is closed. After this, the circulation in the underfloor heating system stops. When the liquid cools, the valve opens.

Big square

If a warm floor is arranged for a large room or a private house, then it is advisable to install a mixing unit, which will be the distributor of the heating system into two circuits. One circuit will be high-temperature, it will provide a coolant supply of up to 90 0 С to heating radiators. The second circuit will provide coolant supply up to 50 0 С to the warm floor.

Such a system consists in the operation of a large circuit, which will provide heating radiators, and a three-way thermostatic valve is installed on the return. It provides a coolant with a cool floor circuit. After this, the liquid tends towards the boiler for heating.

Public buildings

If a large amount of work is being done to install a heated floor in a public building or a multi-story residential building, a complex heating system is arranged. The building is divided into separate zones or a large mixing unit is mounted, which will provide mixing for all contours of underfloor heating. Mixing provides a three-way thermostatic valve.

This system provides knitting of the controller, three-way equipment and drive. The thermostat determines the permissible temperature limits, which will be acceptable for heating using the underfloor heating system. After the mixing unit, the liquid enters the general distribution manifold of the heated floor or the collector located on the floor or in the apartment.

Valve connection

• On the body of the three-way valve, the fluid flow diagram is indicated using the arrows or letters “A” and “B”, where “A” is the hot stream, “B” is the cold stream, and “AB” is the mixed stream. The equipment must be installed in accordance with this scheme.
• The thermostatic valve on the heating radiator can be installed sideways with a thermal head so that it is not affected by external factors, such as a draft from the window leaf or ascending flows of hot air. The thermal head reacts to temperature changes and, if the room is hot, and cold air blows on the thermostat, then the thermal control mechanism will only increase heating.
• Today, there is already equipment with a remote thermostat. It is easier to install where there will be no extraneous influence. Thus, he can more accurately determine the temperature of the air in the room.
• It is important to look at the signs that are on the instrument. There are thermostatic valves with left and right mounting on the radiator.
• If the equipment is installed in an inverted position, then the fluid flowing through it will press its own weight on the poppet valve, and it will open not due to cooling water, but under physical influence.

Diagram of a heating system with thermostatic equipment (valve installation locations shown)

1. Solid fuel boiler - provides heating to the building.
2. Automatic air vent - releases accumulated air from the pipeline.
3. Thermostatic valve - controls the temperature of the coolant.
4. Heating radiator - performs heating of the room.
5. Balancing valve - regulates the pressure in the pipeline.
6. Expansion tank - places excess fluid as a result of its expansion.
7. Shutoff valves - blocks the flow of fluid.
8. Filter - purifies water.
9. Pump - provides forced circulation of fluid through the pipeline.
10. Pressure gauge - determines the pressure in the pipeline.
11. Safety valve - in case of pressure increase in the system, it releases water.

Installation video

You can find out how to install a thermostatic mixing valve by watching the video below.

When installing thermostatic equipment, it is important not only how it will be installed, but also where. Incorrect installation can completely ruin the heating system. Proper connection will provide a comfortable microclimate in the room and the required temperature in the water supply system. In addition, such equipment is able to regulate the pressure in the system. The thermostatic valve is simply necessary for heating and water supply in an apartment and a private house.

In contact with

Modern water heating is not only a boiler, pipes and batteries. Each time we talk about the design of the heating system, “stop-regulating valves” is necessarily mentioned as an integral element of the heating system. This includes several types of devices, each of which performs a special function and contributes to the creation of a practical and efficient system. One of the most important are heat flow control devices.

Why and how to regulate heat flow

Before starting the design of heating, a thermal calculation is performed. Given the possible heat loss of the object, the developer determines the required performance of the heating system and draws up the heat balance of all rooms. Based on these data, heating appliances of the required type and power are selected that can maintain the optimum temperature in the rooms. However, the conditions under which the radiators will operate during operation may vary. There are several factors that influence: air temperature jumps on the street, wind strength, solar activity, heat generation by household appliances, etc.

But we cannot remove or jam individual sections when it becomes hot in the rooms. It turns out that if the main goal is to maintain a comfortable temperature regime, then you need to learn how to otherwise manage the energy that comes from the heat generator. This can be done in two ways, but in both cases, manipulations are made with the liquid circulating through the pipes:

1. Qualitative change in the properties of the coolant. If necessary, cooler or hotter water is supplied to the radiators - just the heat generator is transferred to a different operating mode (it doesn’t matter, it’s a boiler room of a whole neighborhood or a wall boiler in the kitchen in a country cottage).
2. Quantitative regulation of heat flow. In this case, using special devices, we limit the amount of coolant that will pass through the radiators. Thus, a battery with the same surface area will give less or more heat (to a limited extent) to the room. For these purposes, three-way valves for heating and temperature regulators on radiators are used.

In autonomous heating systems for apartments and private houses, a combined method of regulation is used as the most effective.

Scheme of using a three-way valve for regulating the temperature of water in an indirect heating boiler

Important! By regulating the heat flow, we can lower or raise the temperature of the heater, but only to a predetermined limit. This limit is set by the technical characteristics of a particular radiator - more precisely, by its maximum heat transfer.

Three-way valve in the heating system

Device

At first glance, this device resembles a regular yellow metal tee (brass is used, sometimes steel / cast iron), since its body has 3 separate pipes. But inside is a mechanism that automatically controls coolant flows. There are valves with two types of actuators:

• saddle (with a stock that progressively moves up / down);
• rotary (with a rotating ball / sector).

In the first version, a saddle is installed inside the housing, which is blocked by a cone fixed at the end of the working rod. In another design, the rod does not move vertically, but is scrolled by the actuator so that the ball with the opening (as in ball valves) opens or partially blocks the communication between the nozzles. Valves with a ball or a locking working part in the form of a sector are mainly used in household systems, where a large capacity and resistance to very high temperatures are not needed.

Principle of operation of a mixing rotary valve with a sector regulator

type of drive

The working rod is moved using an external drive. It comes in several forms. Most often in domestic installations it is applied:

• Thermostatic direct or indirect action. When the temperature of the coolant changes, the expanding liquid of the thermosensitive element, the bellows, presses on the stem (an attachable thermal head can also be installed here). In some cases, a probe located inside the pipeline is used as a thermostatic three-way valve sensor.
• An electric drive, which is an electromagnet, or a servo drive based on an electric motor. The command to the actuator is given either directly from the temperature sensors, or from the control controller. This drive option allows you to most accurately control the heat flux.

Important! Often such devices are sold without a standard drive, and the user himself chooses the most suitable option for his conditions.

Three-way valve with electric actuator

The three-way valve is not designed to reduce the flow of coolant, its circulation does not stop at any position of the stem. This is its main difference from two-way devices (cranes, regulators). The objective of such a valve is to mix flows or to separate / distribute them.

• The dividing valve allows for quantitative regulation, since it does not allow part of the water along the main direct path, but along the bypass. Two of his pipes are the weekend, and one for the entrance.
• A three-way mixing valve usually mixes cooler with a hot coolant (sometimes vice versa), changing the qualitative characteristics of the heat flow. The level of temperature change is determined by the set proportion of the connected jets. There are two ports (pipe) for entry, and one for exit. The same devices under certain conditions can perform separation functions.

Three-way heating control valves are used in several schemes. For example, in order to temporarily cut off the cold water of the return line and let part of the already heated coolant flow along a short circuit (relevant for solid fuel boilers, in which the condensate forms in the chamber at the beginning of the furnace). These devices are also installed in order to power the DHW circuit by dividing the flows or to prevent overheating of individual branches of warm water floors. Using three-way devices, bypass radiators are often bypassed.

Create a short outline to prepare the return

Temperature controllers

What are they needed for

These devices are installed directly on the radiator plugs. Their direct "duty" is to shut off the flow of coolant passing through the battery - if necessary, even completely. It’s about the same as the faucet does, only here the user can set the values \u200b\u200bhe needs once, and the thermal valve for the heating radiator will continue to maintain the set temperature. Regulators are useless only with cast iron batteries because of high thermal inertia.

Electronic thermal valves have increased accuracy and functionality

How are thermostats

These are two-way devices that consist of a valve and a thermal head. The valve ("valve") is a locking mechanism consisting of a standard set of elements: seat, cone, stem. When the working rod retracts, the gap between the seat and the cone decreases - the flow of coolant decreases, and vice versa.

But it controls the stem of the thermal head. The principle of its action is based on the expansion of a liquid or gas when heated. A heat-sensitive substance closed in a special cylinder (“bellows”), under the action of a too hot coolant, expands and pushes the spring-loaded piston, which, in turn, moves the stem with the cone towards the saddle. When the flow of the coolant decreases, the active substance cools and decreases in volume, and the spring returns the piston, the stem and cone - the duct is strengthened. The cycle is repeated over and over again, so that the heating of the battery can be controlled with great accuracy. The more accurate and faster the thermal head reacts to settings and changing modes, the better (but will cost more).

Types of regulators for the radiator

By the method of setting the temperature and controlling the temperature, thermostatic valves for heating are:

• Mechanical. A preset handle is made with the divisions, the stem moves under the action of a bellows and a return spring.
• Tame. They are not much different from a conventional crane, but such a thermal head can be quickly replaced with a model for automatic operation of the valve under variable conditions.
• Electronic. Equipped with digital panel and battery powered. They allow you to take into account the temperature of the coolant and program the modes in time.

By the type of active substance in the bellows, the regulators are:

• gas
• liquid.

By appointment:

• for two-pipe systems,
• for single pipe wiring diagrams.

By connection method:

• angular
• direct.

Devices for regulating the flow will not increase the power of the heating system, but they will allow you to properly manage the generated heat. It is thanks to these “fighters of the invisible front” that heating becomes comfortable and economical.

Video: three-way valve for heating system

Boiling of the coolant due to overheating is a common problem in the operation of solid fuel boilers. To maintain the required temperature, to connect several circuits to heating equipment at once, a thermostatic valve for solid fuel boilers is used.

Why do we need a three-way valve for a solid fuel boiler

The purpose of a three-way valve in a heating system with a solid fuel boiler is:

• To prevent emergency situations and boiler failure, due to the large difference in the temperature of the water flow at the supply and return of the heating system. Cast iron heat exchangers are particularly sensitive to temperature changes.
• Provide stable heating parameters, while connecting multiple water circuits. When connecting underfloor heating, a three-way valve is included in the binding circuit. If it is required to simultaneously heat several separate buildings, control valves of this type are also used.

How does a three-way thermal valve for a boiler TT work

It is accepted to classify two types of control valves, depending on the principle of the valve:

• Three-way thermostatic control valve for a solid fuel boiler, used to separate the flow of circulating liquid for two heating circuits operating at the same heating temperature. The valve has one input and two outputs, and works, depending on the design, with constant or variable pressure in the heating system.
• A three-way mixing valve for a solid fuel boiler is needed while connecting underfloor heating, with a maximum temperature limit of 55 ° C (optimal indicator 45 ° C) and a radiator system operating at 80-90 ° C. The stream going to the warm floors is diluted with cold water, which reduces the intensity of heating. The three-way valve device has two inlets (for connecting hot and cold water) and one outlet.

The principle of operation of the valve resembles a regular tee, only with a complex internal device. The coolant flows inside the housing from the inlet to the outlet pipe until its temperature reaches a value set by the user. After that, the flow is partially blocked by the rod. At the same time, a second inlet pipe connected to cold water diluting the coolant opens.

The options for using the thermostatic mixing overheating protection valve in the piping depend on the heating circuit. But, basically, the device is installed:

1. For supply or return to warm floors.
2. To the supply pipe coming from the boiler.

Installation is carried out according to the arrows and designations indicated on the valve body. The instructions describe in detail different tying schemes.

How to choose a three-way valve to the boiler

• The operating parameters of the heat carrier are indicated in the technical documentation attached to the boilers. Typically, the return temperature is 45-50 ° C.
• Bandwidth.
• Type of drive - non-volatile three-way mixing valve, has a mechanical regulator. Provides a stable coolant temperature, regardless of the intensity of heating the room. A three-way thermostatic mixing valve for a solid fuel boiler, comes complete with a ball-mounted overhead sensor that responds exclusively to the temperature of the incoming coolant. Used in domestic conditions.
  Electronically controlled devices allow you to set the heating parameters for the rooms. Such three-way thermostatic mixing valves for solid fuel boilers with an external sensor are connected to a servo drive, room thermostats.

What brand of heat mixing valve to put on a TT boiler

• ESBE is a Swedish company supplying shut-off and control valves, almost all over the world. The main focus of the company is on energy-saving technologies and control automation.
  The consumer is offered a range of heat-mixing and distribution valves, with built-in and remote sensors, and the ability to connect to a servo drive. ESBE products are characterized by high quality, reliability and cost-effectiveness.
• Watts is a US company with three large divisions. Shut-off and control valves manufactured in Germany and fully comply with the requirements in force in the EU countries.
  A feature of the product is the release of a separate series of valves designed to be connected to underfloor heating and radiators. The consumer, under the Watts brand, is offered all the components and devices necessary for installation, including temperature sensors, servos, etc.
• Caleffi is an Italian company known for producing control and shutoff valves for such concerns as Viessmann, Buderus, Vaillant, Grundfos. The company places particular emphasis on the production of valves and water distribution units for underfloor heating. The product range offers a fully-equipped mixing unit.
  The company manufactures equipment designed for domestic and industrial facilities. Caleffi thermostatic valves are designed with solid fuel boilers in mind.
• Valtec is a joint, Italian-Russian company, which was established in 2002, with the aim of manufacturing shut-off and control valves for heating systems and water supply. Products are popular due to the optimal ratio of cost and quality of the proposed plumbing equipment.
  All heat mixing valves are subject to a 10 year factory warranty. Risks are covered by compulsory insurance of all manufactured equipment. Valtec products are offered to domestic consumers at the most affordable cost among analogues.
• Herz is one of the oldest manufacturers of sanitary fittings in Europe. The Austrian company has been operating since 1896. Herz owns several patented innovations that have affected the efficiency, appearance and durability of the devices.
  The company focuses on energy-saving technologies. An additional “bonus” is the beautiful appearance of the control valves manufactured under the brand name DE LUXE.
• Danfoss is a company that was created as a small family business in Denmark in 1933. At the moment, the company's staff includes more than 24 thousand people. Products are supplied to more than 100 countries.
  Danfoss products are designed for domestic and industrial heating systems. The range includes thermostatic valves with mechanical and electronic settings. The consumer is offered servos and temperature sensors.
• Systemair is a Norwegian company established in 1974, whose assets are constantly growing. In 2000, the concern's products became available to domestic consumers. Production workshops manufacturing products for Russia are located in Lithuania, Turkey, and since 2011 in the Russian Federation, which has reduced the cost of products.
  All sanitary fittings Systemair, is subject to mandatory certification. Constant quality control is carried out.
• Barberi is an Italian company manufacturing simple control devices with a high degree of reliability. Mixing units with built-in heat-sensitive elements are especially popular.
  Barberi mechanical heat mixing valves are designed for open and closed heating systems. The L-comfort series is designed for connection to underfloor heating.

How and where is the boiler thermostatic valve TT installed

• Boiler protection - the correct installation of the control valve is carried out on the coolant supply, with a non-closing opening towards the boiler. The mixing unit is installed exclusively on the return line. Immediately after the boiler is turned on, the coolant circulates in a small circle of the heating system, after heating, the valve starts to pass fluid into the water circuit.
• Temperature control in heating circuits - hydraulic piping provides for the installation of a collector between the boiler and the valve. The mixing unit, in this case, is set exclusively for supply. The connection diagram with a three-way heat mixing valve implies installation after the control unit. The distribution check valve is placed on the return line.

To facilitate installation, the flow diagram of the coolant with a three-way heat-mixing or distribution valve is indicated on the valve body, arrows or letter designations. The unit can be installed exclusively in the direction indicated.

The thermostatic valve is a necessary device for strapping solid fuel boiler equipment. Installation of the valve is also required when simultaneously connecting several heating circuits with different temperature characteristics.

Good day, dear reader! I don’t know for what reason, but our five-story house is heated so well that even in cold weather it was too hot. The windows in my apartment were constantly open for ventilation, and huge amounts had to be paid for heating. There was something to do with this.

So I decided to install a separate heat meter and. Now I have enough warmth in the apartment, and the amount in payments has decreased by almost half.

Thermal valve is a type of pipe fittings. It allows you to maintain the specified temperature in the room by optimizing the heat transfer of a separate heating device.

Purpose and scope

The thermal valve is designed for manual or through a radiator or distribution manifold.

1. In autonomous heating systems, where the carrier is heated by a solid fuel boiler.
2. On pipelines of hot water supply. Water for domestic use can be supplied too hot (up to 95 ºС) and in the absence of a mixer tap causes burns to users.
3. In front of the plastic elements of the piping system. The thermal valve protects the material from which the pipes are made from overheating.

Specifications

For reference, I will give a number of basic technical characteristics of thermostatic valves:

1. The maximum level of working pressure is 1.0 MPa.
2. Pressure test before commissioning - 1.5 MPa.
3. The maximum working temperature is +110 ºС.
4. The most admissible ambient temperature is +50 ºС.
5. The valve capacity is from 1.6 to 2.5 m³ / h.
6. The temperature control range is + 20 ... + 60 ºС.
7. Response time - 25 minutes.
8. MTBF with manual control - 8000 cycles.

What materials are made of

For the manufacture of a thermostatic valve body, corrosion-resistant metals are used:

• Brass.
• Bronze
• Stainless steel.

Additionally, the surfaces of the brass products are nickel-plated, and the bronze body is either nickel-plated or coated with a layer of chromium.

Device and principle of operation

The thermal valve includes two main components:

• Valve.
• Thermostatic head.

The design of the thermostatic valve is a hollow body with a cover. Inside it is a movable stem with a sealing surface that provides a tight seal of the valve seat. The stem is spring-loaded with a return spring; a ring with a washer is provided for its fixation.

The valve threaded cover is equipped with a packing assembly consisting of a packing ring and a nut. To provide additional tightness to the joint, a sealing ring is installed on the stem.

The radiator thermal valve is connected to the devices by means of a half-bend having a lock nut with a Teflon insert. It is fixed to the device body with a union nut through a gasket.

In the cavity of the thermostatic head is a bellows filled with a thermosetting substance, and a stem. As the temperature rises, the filler in the bellows tank expands and acts on the stem, which, in turn, transfers force through the extension to the stem of the thermostatic valve. When the valve stem lowers, it blocks the flow of coolant.

In a radiator circulation slows down, heat transfer decreases. A spring mechanism is provided for returning the stem. The thermostatic head is attached to the valve by a brass union nut.

Advantages and disadvantages

The advantages of installing thermostatic valves in a heating system include the following factors:

• Non-volatility device.
• Compactness.
• High precision temperature control.
• Easy operation and high reliability.
• Aesthetic appearance.
• The optimal combination of price and functionality.

The disadvantages of using thermostatic valves are:

• The complexity of the settings.
• Danger of malfunctioning of the thermal head under the influence of a draft or a nearby furnace.

Kinds

Thermal valves are divided into types according to the following characteristics:

• By the installation method - direct, angular, axial.
• By appointment - mixing, balancing.
• By type of heating system - for a single-pipe or two-pipe system.
• By type of filler in the bellows container of the thermocouple - paraffin, gaseous or liquid substance.
• By type of thermostatic element - manual, mechanical or electronic regulation, with a remote sensor.

Hand held

For manual thermostatic valves, the stem is triggered to stop the flow of coolant when the handle is rotated manually outside the body. By turning the regulator, you can change the pressure in the thermostatic head, which will affect the sensing element and set the rod in motion. They are direct or angular.

Available in two diameters of the passage - ½ "or ¾". Differ in simpler design and low price. The main disadvantage of a thermostatic valve with manual adjustment is the low accuracy of temperature control and the need to control timely operation by a person.

Mechanical

These are devices with a more complex design that can automatically maintain a given temperature in the room. The basis of their thermostatic head is a bellows tank filled with a liquid with a high coefficient of thermal expansion.

When heated, the fluid in the bellows expands and drives the stem of the thermal head. It transfers force through the extension cord to the stem of the thermostatic valve, which blocks the flow of coolant. When cooling the liquid, the process goes in the opposite direction

Gas or liquid

The efficiency of a thermostatic valve depends on the properties of the substance in the bellows. Gas-filled thermocouples are more accurate and reliable. They respond faster to temperature changes, but are more difficult to manufacture and therefore more expensive.

Liquid ones work a little slower, but easier to manufacture. The advantages of liquid thermocouples also include the high accuracy of transferring the internal pressure of the bellows to the thermostatic valve stem.

With remote sensor

Designed for installation in radiators with a bottom connection or located in a niche. The thermostatic head is mounted on the valve using a threaded connection, and the temperature sensor is attached to the wall in any convenient place. Between themselves, the head and the sensor are connected by a capillary tube.

Such models maintain the temperature more accurately, but at a price more expensive than others.

Electronic

Electronic thermal valves have larger dimensions. An electronic microprocessor that controls the movement of the rod is built into the device’s case; there is also an additional compartment for two batteries. One of the advantages of electronic models is its wider functionality. With their help, for example, you can set different room temperatures in the morning or evening, for each day of the week.

Life time

Most manufacturers claim that the estimated service life (subject to operating rules) of the thermostatic valve is at least 15 years.

How to choose

The thermostat is selected in accordance with the operating characteristics of the heating system. The device must:

1. Maintain pressure in the range of 16–40 bar and temperature up to 200 ° С.
2. Made of corrosion resistant materials that are resistant to mechanical stress.
3. Match in diameter with the size of the pipeline.
4. Match the parameters of the thread on the pipe.

Popular manufacturers

Thermostats made by the following companies are considered the most reliable and durable:

• Danfoss (Denmark). The devices of this manufacturer, despite the rather low price, have an improved design. They are equipped with a flow stabilizer, so they operate silently. Do not clog when working with a coolant of any contamination, since the stroke of their rod is 1.5 times more, and the performance tuning window has an enlarged section.

• Oventrop (Germany). The variety of sizes of Oventrop thermostatic valves allows you to choose the perfect model for any engineering system. Excellent regulatory qualities, high product reliability are combined with an aesthetic appearance.

• Luxor (Italy). Luxor thermostats are suitable for heating systems where the heating medium is hot water. They are equipped with a thermostatic spindle for presetting the flow.

What determines the cost and the approximate price

The cost of thermostatic valves is different and depends on:

• From the design.
• Material of body parts.
• Technical specifications.
• Production features.

How much different models of thermostatic valves cost, see the table.

Rules for installation and operation

I install the thermostatic valve as follows:

1. I drain all the liquid from the heating system. In a private building, this is easier to do, and for draining in an apartment building you will have to contact the service organization, since the valve is in the basement.
2. I cut out the part of the pipe corresponding to the size of the purchased device.
3. I cut the threads at the ends of the pipes.
4. I screw the product into the thread on the pipes with the joint seal with linen thread on heat-resistant paint.
5. I check the tightness of the joints, the motionless position of the valve body.
6. I adjust the thermocouple.

During operation of thermostatic valves, I try to:

1. The device was protected from direct sunlight.
2. The valve was closed during the ventilation of the room, as cold air quickly cools the thermostat, and it will increase the flow of hot coolant into the radiator.
3. If the device is configured to control the temperature in several rooms at the same time, then I make sure that the interior doors are closed.
4. Until the next heating season, all valves remained open. Otherwise, spool sticking to the valve seat and device failure can occur.
5. In the summer, I remove the thermostatic head from the valve. This will increase its service life.

Instrument adjustment

After installation, I adjust the device as follows:

1. I fully open the valve until it is heated and the temperature in the room stabilizes.
2. Then I close it completely and wait until the room temperature becomes comfortable.
3. I remove the handle of the thermostatic head and set it again so that the desired temperature on its scale is reached when the valve is fully open.
4. After that, I begin to open it a little, until the coolant starts to flow into the battery, and the thermostatic valve body becomes warm to the touch.

Common installation errors and problems

Since the head of the thermostat must freely come into contact with air during operation, the following errors must not be allowed when mounting the device:

1. Set the head upright. Air heated by the inlet pipe will fall on the thermostatic head, which will not allow it to correctly assess the temperature in the room.
2. Install the device without regard to flow direction.
3. Close access to the valve of the main air mass with furniture, blackout curtains, decorative screens, etc.
4. Place under a wide windowsill or in a niche where there is a zone of increased heating.

Errors in the placement of the thermostatic head lead to the creation of a zone around it with warmer air than indoors. Therefore, the device will block the movement of the coolant too early and will not allow you to create the optimal temperature regime in the room.

A few tips from professionals will help the apartment owner to install and configure the thermostatic valve with his own hands and in accordance with all the rules:

1. It is important to mount the device so that the direction of water movement coincides with the direction shown by the arrow shown next to the marking on the case, otherwise the thermostatic valve will not work correctly.
2. For underfloor heating systems it is better to choose thermostats with a side valve - this facilitates access to the setting.
3. In public areas for installation, thermostatic valves with remote control or presetting must be used to protect them from unauthorized persons.
4. To seal the threaded connection, not fum tape, but polymer or linen threads with heat-resistant paint should be used. When heating and significant temperature differences occur, the nozzles undergo thermal expansion, the tape packing density may be affected, which will lead to leakage.
5. The valve is more appropriate to place on the supply pipe.
6. The distance from the floor to the installation site of the thermostatic valve should be at least 40-60 cm. Initially, manufacturers configure them to capture temperature changes at this level. If it is necessary to change this parameter, an additional adjustment of the device is performed.
7. The thermostatic head must be installed on the valve in a horizontal position and be turned deep into the room. If you install the thermal head vertically, then warm air from the riser will interfere with the normal operation of the sensor.
8. When installing a thermostatic valve in a single-pipe heating system, an additional bypass section is required - bypass. It must be between the sections of pipelines entering the heater and exiting from it (as in the photo below).