Thermostat for a boiler - thermostat: temperature control, types. Electronic thermostat for a boiler How does a thermometer work on a boiler?

The thermostat for a water heater plays as important a role as the fuse in any electrical network. The user sets the required water temperature in the water heater, and the thermostat maintains it. That is, it allows the heating element to work until the water temperature reaches a set value.

Then the heating element stops working. The water temperature decreases (forced or naturally) and the thermostat again gives a signal to the heating element to begin its direct duties.

Separate, specially designed types of thermostats have additional function– turn off the power supply to the heating element if the latter breaks down. This avoids the possibility of electrical shock, which often happens with ungrounded boilers.

Types of thermostats

Today, many types of thermostats have been developed, but if we talk about devices specifically for boilers, the three most successful are:

Rod. Such a thermostat is represented by a tube of small diameter (usually up to 10 mm) and short length (no more than 35 cm). The operating principle is based on the elementary laws of physics: when heated, the tube expands linearly, which allows you to press the switch. Such thermostats for a long time were the most common in boilers. However, their accuracy left much to be desired - when hot water left the water heater, the incoming cold water instantly cooled the thermostat due to the latter’s close location to the inlet cold water. Thus, the boiler could work beyond the allotted time, and this significantly affected financial costs.
Capillary. A more progressive type of thermostat, also working according to the laws of physics. The tube in which the temperature-sensitive cylinder with liquid is located is usually made of a material that cannot be oxidized over a long period of time. Inside the cylinder there is a liquid that has a different density from water. When heated, the density of the liquid changes, the volume changes accordingly, and the liquid presses on a special membrane, which turns off the power. Such thermostats are more accurate when compared with rod thermostats. The temperature deviation is approximately 3°C.
Electronic. More modern type and, accordingly, more accurate. It usually works in tandem with a protective relay - if the boiler is empty when voltage is supplied to the heating element, then the protection will work and turn off the power.

According to another classification, all thermostats can be divided into:

Electromechanical and electronic. The first type works due to bimetallic elements, the second - thanks to electronic special sensors.
Simple and programmable. In the first type, the temperature is set manually mechanically. The second type is more precise in its work.
Overhead and mortise. For boilers, the overhead type is most often used if the control is electronic, and the mortise type if the control is mechanical.

Another interesting option– thermostats designed for indirect heating boilers. Such boilers allow you to heat water using only power for the heating device, which means significant savings. But circulating in heating system the liquid cannot heat above a given level, while for a boiler the consumer may need a different temperature (and most often this happens). In this case, you should buy a thermostat specially designed for this purpose.

Having carefully studied the articles on self-production, you can try to make a thermostat yourself.

Malfunctions and their solutions

The thermostat for your water heater may fail. Unfortunately, such phenomena are not uncommon, but there is nothing fatal here. Firstly, as a rule, there is no repair - a thermostat that has worked faithfully is thrown away and a new one is bought. Buy the same or with a different resistance - the choice is up to the consumer. Secondly, when correct operation water heater thermostat breakdown can be avoided or, in extreme cases, its life can be significantly extended.

How does a consumer notice a broken thermostat? As a rule, this is the most common method - the water is not heated in the boiler. In this case, there may be either a malfunction heating element, either a malfunction of the thermostat itself, or (less commonly) a malfunction of both elements. To check the latter, its resistance should be measured.

If during testing the picture on the display of the test device does not change, you need to buy a new thermostat. It's not that much money, so there's no need to grieve. Another option for testing the thermostat is possible: measuring the resistance when the thermostat itself heats up. If even then the test device does not show any changes, that’s it, now it’s time to go to the store.

How to choose

Typically, a faulty thermostat can be replaced with a similar one in shape and operating principle. However, if it is possible to buy and install another thermostat and there is an urgent need for it, then why not. The main thing is to be able to choose the right device and install it correctly. Although here, too, the consumer can be helped by the Internet or a consultant at the point of sale.

But we should not forget: any independent actions Without certain knowledge and strict adherence to safety regulations, they can lead to a very unpleasant outcome.

It would seem that the heating element or volume should be important in a boiler, but, as it turned out, the thermostat and its role cannot be neglected. By setting the desired temperature and protecting the boiler from overheating, the thermostat is extremely important in the operation of the heating device.

Can be used both for heating (as part of a radiator) and for providing housing hot water. The first thing that needs to be done when putting it into operation is to protect the system from possible breakdown of the electric heater, as well as create conditions for it battery life. A popular method of solving this problem is to use a thermostat for the heating element. This small device, also called a thermostat, can help solve many problems.

Composition of water heating equipment

The simplest water heating or heating element should consist of at least three elements - a water tank, a heating element - heating element, and a thermostat. The tubular heater can be immersed or dry. In the first case, it is made of stainless steel and placed inside the tank. Water is heated by direct contact of water with the heating element.

Dry heating elements are made of ceramic and are located outside the water tank. Heating of the coolant occurs due to the transfer of thermal energy through the wall of the tank. Such elements are easy to replace if they fail.

The thermostat for the heating element is designed to control and maintain the set temperature of the coolant, as well as to emergency shutdown a tubular electric heater from the network if the boiling process begins (as a rule, this happens when the heating element breaks down).

There are several types of thermostats, each of which is advisable to use with certain type tubular electric heating element.

Basic operating principles

Regardless of the design and design, all thermostats operate according to the same scheme. To operate, the thermostat must be built into the tank and also connected to the heating element. The entire temperature control process can be divided into 4 stages:

The toggle switch sets the required temperature range of the coolant.
A thermostat for a heating element with a programmed mode measures the degree of water heating and gives a command to turn on the device.
When the water temperature reaches the set upper heating limit, the thermostat opens the electrical circuit and turns off the heating element.
After the water has cooled, the whole process is repeated.

It's worth noting that no matter what temperature range you set, the thermostat will turn off the heating element if the water starts to boil. This is necessary to prevent damage to heating equipment.

During boiling, the process of intense vaporization begins. Along with the amount of steam, the pressure inside the tank also increases. As soon as the pressure value exceeds a critical level, the tank will explode. The thermostat for the heating element prevents this from happening by opening the electrical circuit in advance.

Types of thermostats

The principle of operation of the device always remains the same. Only the principle of determining the coolant temperature depends on the type of thermostat. According to this, all thermostats are usually divided into rod, capillary and electronic.

Rod devices, as the name implies, have the shape of a rod with a length of 25 to 50 cm. The principle of determining temperature is based on the difference in the coefficient of specific thermal expansion of two metals. The rod thermostat is installed outside the water tank in a special tube.

The capillary thermostat of a heating element for heating water is a hollow tube, inside of which a special liquid is “sharpened”. As the temperature rises, it expands, begins to put pressure on the walls and acts on the membrane, which opens the circuit. When cooling, the reverse process occurs.

Job electronic thermostats is based on the ability of materials to change their ohmic resistance along with changes in temperature. As a result, the voltage in the device increases or decreases, which is registered by special sensors and the heating element is turned off or on. Electronic devices are the most complex and expensive, but at the same time the most accurate.

Heating elements with built-in thermostats

A heating element separate from the thermostat is rarely used in practice. As a rule, this solution has proven itself only in water heating boilers. with a thermostat are much more common.

In such “combined” devices, the thermostat is located in a separate tube, and it is easy to replace if it breaks down. When choosing devices in this category, you need to pay attention to the following points:

Case material. It can be represented by “stainless steel” (the cheapest and most common devices), as well as copper. Copper appliances last longer, but are also much more expensive.
Power. For a home electrical network, choosing devices more powerful than 2.5 kW is dangerous - there is a risk of overload and short circuit. When using more powerful heating elements, lay a separate power cable.

When choosing a battery, you should not focus on expensive models. Practice shows that the durability of devices does not depend on price. The service life is determined by water hardness, loads and stability of the electrical network.

Areas of application of heating elements with a thermostat

The scope of application of a heating element with a built-in thermostat is quite narrow, due to high energy consumption and short service life. They are most widespread in water heating equipment. This “water tank” is installed in the shower or kitchen and serves as the main or backup source hot water.

Very rarely, tubular electric heaters are used for space heating. In this case, the element is installed directly into the radiator through a special fitting. The main advantages of installing a heating element with a thermostat in a heating radiator are speed. With this simple solution you can very quickly provide your home with a backup heat source.

Features of heating elements for cast iron batteries

Tubular electric heaters for conventional and cast iron radiators there is practically no difference. The only exception is the material of the plug - it must be made of cast iron or an equally heat-resistant material.

In addition, the shape of the outer part of the housing where the thermostat is installed may also differ. In this case, the length of the heating element should be 5-10 cm shorter than the length of the radiator. Otherwise, water circulation and heating cannot be achieved. Therefore, before purchasing, make sure that the heating element with a thermostat for cast iron batteries intended.

Thermostats on the market

Thermostats for heating elements can be called consumables. That is why it often comes separately from the heating element. To replace it, you just need to select a similar device on the market. To do this, find out:

Dimensions, type and method of fixing a failed device in the tank.
The maximum current that the new thermostat will have to handle.

The best option would be to purchase the same device that has become unusable. This can be done by contacting the store with a faulty thermostat. In most cases, sellers themselves will select the necessary device for you.

The thermostat for a water heater is a fairly important part. It is he who is responsible for maintaining certain temperature at a constant level. The thermostat for the water heater is capable of slowly adjusting the temperature, and it is also equipped with a device that protects it from cooling and overheating. When the need arises, he turns on and off the type, that is, the heating element.

This device allows the user to set a specific operating mode, and also maintains a temperature level at automatic mode. If the water temperature decreases, it turns on the heating element, due to which the temperature rises to a certain specified level.

The thermostat for a water heater has a certain operating principle. It is worth saying that it is similar for all types of water heaters. On the screw with which each thermostat is equipped, a certain required water temperature is set. When the swelling valve is tightened, hot and cold water begins to flow into the mixer system, and then the adjustment process begins. The temperature of the water is measured in the chamber, after which the warm water is mixed with cold water required proportions. When supplying water for mixing, hot water has priority, so it will be supplied until its temperature is higher than the set value. After this, the process of mixing it with cold water. Thanks to this fact, it can be explained that the thermostat for the water heater does not respond so quickly. However, the user usually does not experience any particular inconvenience.

If the thermostat for the water heater is installed in a system where there is no circulation warm water, then it is possible that cold water will enter the incoming stream at initial stage. In systems where there is circulation of warm water, the thermostat adjusts the required temperature in an instant.

Storage and flow units are usually equipped with different heating elements. Usually the heating elements are flow models have more high power. That is why the choice should be made only after you have decided on its purpose.

An electric thermostat may have normally closed or normally open bakelite. Often owners of water heaters decide to do-it-yourself repair. The thermostat for the water heater "Ariston" and other companies is an electrical part, so it is worth remembering that different warranties are given for the tank itself and for it. If you need to replace any element of the water heater or have it repaired, you should contact service center or directly to the manufacturer, where you can find out whether it is subject to warranty repairs. It is important that the appropriate thermostat model is available.

If you are interested in where you can buy this device, when yours fails, it is worth noting that most companies involved in the production of such equipment provide delivery throughout the country. For example, you can order a thermostat for a Thermex water heater at home. It is easy to replace it yourself using simple recommendations.

On this moment One of the current purchases for the home is the purchase of a water heater (boiler), which is explained by the enormous popularity autonomous heating and hot water supply.

The prerequisites for this process were the increase in the cost of centralized hot water supply and the ability of people not to depend on the hot water supply schedule, which is especially important in summer period in our country.

Purchasing a water heater is not as simple a process as it might seem at first glance. Buying a boiler requires care and attention in order for the device to serve effectively and for as long as possible, without causing the owners much trouble.

Types of thermostats

The boiler itself is quite simple. You can even install and connect the device yourself. But when choosing a unit, you need to pay attention to what kind of thermal relay is installed in it. For example, if it has temperature control or lacks it. Exists several types of thermostats, on the basis of which water heaters are divided into several types:

Programmable or simple. This affects temperature management.
Electromechanical or electronic. The control of the device depends on this.
Mortise or overhead. The installation of the unit depends on this.

Most common rod, electronic and capillary thermal switches. Rod models are obsolete and consist of a tube 35 cm long and 1 mm wide. Their operating principle is as follows. When exposed high temperature the tube expands in size, causing pressure on the switch. The disadvantage of this model is its inaccuracy. Because the tube cools too quickly, the boiler runs longer than necessary.

The operating principle of the capillary thermostat is more modernized. A capillary thermostat is a tube containing cylinders filled with a liquid that differs in density from water.

As the temperature rises, the liquid filling the cylinders of the capillary thermostat increases in volume and begins to put pressure on the membrane and the switch. The error in the discrepancy is 3 degrees.

Electronic thermostats are the most common models and the most accurate. The advantage of this model is in direct interaction with the protection relay. Thanks to its presence, emergency automatic shutdown supply if there is no liquid in the tank.

Thermostat for water heater

The thermostat provides safe work water heater. This process is explained as follows: when the water temperature rises, the pressure inside the tank, which is sealed, increases.

When the increase in pressure is not controlled, then all the structure will explode, which is dangerous not only for equipment and surrounding objects, but also for human health if a person is nearby during the explosion.

The thermostat allows you to keep the temperature at required level. Bottom Line: Temperature Controller protects against explosion, overheating, damage to equipment and property, ensures the safety of people.

Most manufacturers try to equip the boiler with a thermostat, because this is what controls water heating at the moment when the device is connected, and for timely blocking of the heating element.

Available on the market a wide range of models, but the principle of operation is the same for all of them. At the moment when you need to connect the device to the network, you need to immediately adjust the water heating level, which is done using the control panel, which is located on the body.

Next you need to adjust the water heating. The relay that is installed on the thermostat will be responsible for opening the contacts of the heating element. When the tank has completely cooled down, the temperature will drop and become lower than normal. In this moment the contacts will close The heating element of the relay, due to which the system will start again and the liquid in the tank will begin to heat up again.

Replacing and connecting a thermostat for a boiler

If the water heater does not work, it should not be restarted. If it does not start, it means the unit is not working! And you shouldn’t expect it to suddenly turn on; you need to check for problems. If it is determined that the problem lies in the thermostat, it must be replaced. The main thing is the ability to choose the right device and install it correctly. Both online resources and consultants in a store or market will help you figure this out.

To replace the thermostat, you must perform the following manipulations:

disconnect the boiler from the power supply;
shut off the water supply to the tank with a special valve;
drain all the water that is there from the tank;
remove the bottom panel of the device, this will allow you to get to the heating element;
remove the pressure ring located on the heating element;
remove the sensor in the thermostat and the control unit;
install a new regulator;
return the pressure ring to the heating element;
Replace the bottom panel of the device.

To purchase the necessary new thermostat for your boiler, you must adhere to the recommendations of specialists. Going to outlet To purchase a regulator, you need to take the technical data sheet of the device with you. With it, it will be much easier for the sales consultant to figure out which model and with what characteristics you should choose.

When purchasing a thermostat yourself, you must remember that it must be the same model, as it was before. Even the smallest difference can lead to failure of the entire water heater. You need to buy a thermostat taking into account the type of product, parameters, installation methods, which labor force current and functionality it has.

Common thermostat problems

Any device, even the most reliable and expensive, fails over time, which is facilitated by many different factors, both internal and external. Breakdowns that require close attention:

If you do not have knowledge and skills in working with thermostats and connecting them, then it is better entrust this issue to specialists. This will allow, on the one hand, to relieve you of unnecessary doubts and worries, and on the other hand, to ensure correct work unit and the safety of others.

The thermostat for your water heater plays as important a role as the fuse in any electrical circuit. The user sets the required water temperature in the water heater, and the thermostat maintains it. That is, it allows the heating element to work until the water temperature reaches a set value.

This is what the device looks like for adjusting the temperature of water heating and for emergency shutdown

Then the heating element stops working. The water temperature drops (forcibly or naturally) and the thermostat again signals the heating element to begin its direct duties.

Separate, specially designed types of thermostats have an additional function - to turn off the power supply to the heating element in the event of a breakdown of the latter. This avoids the possibility of electrical shock, which often happens with ungrounded boilers.

Types of thermostats

Today, many types of thermostats have been developed, but if we talk about devices specifically for boilers, the three most successful are:

Rod. Such a thermostat is represented by a tube of small diameter (usually up to 10 mm) and short length (no more than 35 cm). The operating principle is based on the elementary laws of physics: when heated, the tube expands linearly, which allows you to press the switch. Such thermostats have long been the most common in boilers. However, their accuracy left much to be desired when hot water left the water heater. the incoming cold water instantly cooled the thermostat due to the latter’s close location to the cold water supply. Thus, the boiler could work beyond the allotted time, and this significantly affected financial costs.
Capillary. A more progressive type of thermostat, also working according to the laws of physics. The tube in which the temperature-sensitive cylinder with liquid is located is usually made of a material that cannot be oxidized over a long period of time. Inside the cylinder there is a liquid that has a different density from water. When heated, the density of the liquid changes, the volume changes accordingly, and the liquid presses on a special membrane, which turns off the power. Such thermostats are more accurate when compared with rod thermostats. The temperature deviation is approximately 3°C.
Electronic. A more modern type and, accordingly, more accurate. It usually works in tandem with a protective relay - if the boiler is empty when voltage is supplied to the heating element, then the protection will work and turn off the power.

According to another classification, all thermostats can be divided into:

Electromechanical and electronic. The first type works due to bimetallic elements, the second - thanks to electronic special sensors.
Simple and programmable. In the first type, the temperature is set manually mechanically. The second type is more precise in its work.
Overhead and mortise. For boilers, the overhead type is most often used if the control is electronic, and the mortise type if the control is mechanical.

Another interesting option is thermostats, which are designed for indirect heating boilers. Such boilers allow you to heat water using only power for the heating device, which means significant savings. But the liquid circulating in the heating system cannot heat up above a given level, while the consumer may need a different temperature for the boiler (and most often this happens). In this case, you should buy a thermostat specially designed for this purpose.

After carefully studying the articles on self-production, you can try to make a thermostat yourself.

Malfunctions and their solutions

The thermostat for your water heater may fail. Unfortunately, such phenomena are not uncommon, but there is nothing fatal here. Firstly, as a rule, there is no repair - a thermostat that has worked faithfully is thrown away and a new one is bought. Buy the same or with a different resistance - the choice is up to the consumer. Secondly, with proper operation of the water heater, thermostat breakdown can be avoided or, in extreme cases, its life can be significantly extended.

How does a consumer notice a broken thermostat? As a rule, this is the most common method - the water is not heated in the boiler. In this case, there may be either a malfunction of the heating element, or a malfunction of the thermostat itself, or (less commonly) a malfunction of both elements. To check the latter, its resistance should be measured.

How to choose

But we should not forget: any independent actions without certain knowledge and strict adherence to safety rules can lead to a very unpleasant outcome.

Purpose of a thermostat for a water heater

The thermostat for a water heater is one of the elements of any boiler. If it were not for its presence in the design of the water heater, then calling such a device automatic would be a great exaggeration.