Thermostat for heating elements: types and principle of operation. Heating element with thermostat for heating water Immersion heating element - heating element
For the effective transformation of electric current into thermal energy, a heating element is used.
Tubular electric heater is used in modern electric boilers, stoves, electric kettles and other devices that provide electric heating.
Heat is released due to the heating inside this device of a nichrome filament, which runs exactly along the center of the tube and is reliably isolated from its surface by a layer of dielectric. As an insulating layer, ceramics are usually used, which transfer heat well, while not passing electric current to the outer surface of the heating element.
Advantages and disadvantages
Among the few shortcomings of these devices, only one can single out: a not too long service life and the impossibility of repair when the heating element burns out.
There are many more positive features:
- High efficiency.
- Reliability.
- Electrical safety.
- Possibility of equipping .
Varieties
Heating elements come in various shapes, capacities and heating environments.
The most popular varieties:
Tubular
This design is most widely used in water heaters. The cost of such elements is quite high due to the stainless steel and nichrome used in their production.
These devices, with high-quality manufacturing, can last more than 10,000 hours.
finned
The heating element in its design differs little from the tubular one. The only difference is the stainless steel fins that are perpendicular to the main heating device. This design allows you to increase the power of the heating element due to the larger area of the heated surface.
A block of electric heaters that are used in high power installations, such as electric boilers.
The use of such heating elements allows you not to be afraid of a complete failure of the heating device. In the event that one heating element burns out, the boiler only slightly loses power and continues to operate in this state until it is possible to replace the failed heating element without the threat of defrosting the heating system.
Cartridge
Such a heating element is convenient in that it allows you to replace a damaged device even in a water heater filled with liquid in a matter of minutes without depressurizing the tank. Like a cartridge, this element is inserted into a metal shell, which, in turn, is already in contact with the heated medium.
The cost of such devices is slightly higher due to more accurate processing of the heated surface.
Heaters of this design are mainly used for heating liquids.
The thermostat allows not only to set the required temperature, but also set to maximum heating does not allow the liquid to boil, eliminating the possibility of an explosion of such a heater.
A matter of choice
Eternal heating elements do not exist today. When heated, the metal gradually becomes thinner at the bends and sooner or later the filament breaks. Premature failure of the heating element may be associated with overheating, especially often hot water heating elements that are switched on during the lack of water in the water heater burn out in this way.
The correct choice of the heating device will allow the device to serve for many years without replacing the heating element.
A high price is not always a criterion for the right choice, there are numerous cases when expensive heating elements of a well-known company worked for no more than 6 months.
Selection rules:
- It is necessary to check that the seller has documents for the goods being sold. The guarantee that the manufacturer gives for the heating element is also an indirect sign of high quality products. The higher the warranty period, the more reliable the purchased product.
- The correct choice of heating elements cannot be made without the selection of the heating element by power needed to heat up the liquid. If the heating element is less powerful than necessary, then the water will not heat up to the temperature for which the water heater is designed. In the event that the element consumes a large electrical power, excessive stress on the wiring is possible. Therefore, when replacing this element, it is necessary to select a heating element of only such power for which this water heater is designed.
- When choosing, it is necessary to choose modern devices for disconnecting the supply of electric current. The most advanced in this regard are thermostats, in which electronics are used to adjust the heating temperature. Devices in which the working element is solid-heat elements that expand when heated are outdated and have a limited working life.
- The correct choice is only possible if the device can fit freely in the tank, otherwise the installation of such a heater will fail.
- Particular attention should be paid to the choice of heating element, which will be installed directly in the heating battery. In this case, in addition to size, an important criterion for choosing an element is the thread number on which this device will be installed.
- If you need to replace a burned-out heating element, then when going to the store for a new element, you should take the burnt one with you and pick up exactly the same in size and marking.
Installation and replacement
For installation work, you will need the following tools:
- cross and slotted screwdriver;
- pliers;
- spanners;
If the heating element is being replaced, then before installing a new element, dismantling of the failed heating element is carried out.
Before proceeding with this operation, it is necessary to de-energize the water heater by removing the plug or turning off the machines on the central electrical panel if the boiler is connected directly.
Installation is carried out in the following sequence:
- Wash the tank thoroughly from the formed scale and wipe it with a rag.
- The new heating element is installed in this way so that the rubber gasket is evenly attached to the surface of the parts to be joined. All threaded connections must be tightened to the required torque. When the heating element is installed, electrical wires are connected to it.
- Then the bottom cover is installed, and the boiler is filled with water. If there are no leaks, then you can turn on the water heater in the electrical network.
If it is required to install a heating element in a heating battery, then a plug is unscrewed at the bottom of the heater and a heating element is installed in its place. Then the system is filled with liquid and the heater is connected to a 220 V variable network.
Price
Block heating element with thermostat type "Ariston" (I)
This device has a built-in thermostat, which allows you to adjust the operation of the device to heat the liquid in the range of +20 - 80 degrees. The working surface of this device consists of copper, which contributes to the most efficient heat transfer.
Price - 1000 rubles.
This device can be used both in factory-made water heaters and in self-made water heaters. In the body of the heating element there is a hole for installing a thermostat, which are purchased separately.
The cost is 1200 rubles.
TENB-9 stainless steel 220/380V
Block of heaters for a water boiler. On one flange of this device, 3 elements with a total power of 9 kW are fixed. The heating elements are reliably isolated from each other, which allows you to adjust the power of heating the liquid. The heating element is made of stainless steel, which protects the heating element from corrosion, and allows the equipment to operate smoothly for up to 5 years.
Price - 1300 rubles.
- Do not try to fix a burned-out heating element - this is a useless exercise. If the heating element fails, it must be replaced with a similar device.
- The water heating element must be immersed in liquid during operation. Otherwise, the device will fail very quickly due to overheating.
The storage electric water heater consists of the following elements:
- tank or body;
- polyurethane thermal insulation;
- inner tank - a container in contact with water, covered with glass porcelain, enamel or stainless steel;
- magnesium anode to protect against corrosion;
- heating elements (TEN);
- thermostat for temperature control;
- safety valve to relieve excess pressure in the tank.
The thermostat, like the heating element, is an important component of electric water heaters. The heating element heats the water, and the thermostat is responsible for maintaining, adjusting and heating the water to the required temperature. In addition, he is also responsible for the safety of the device, since it turns off the heating element when the water temperature becomes critical and steam begins to form.
Types of thermostats (thermostats) and the principle of operation
Typically, the following types of thermostats are used in water heaters:
- rod (bimetallic);
- capillary;
- electronic.
The principle of operation of the capillary thermostat is pneumatic. The pressure inside the flask with gas, which contains the thermostat, varies depending on the temperature. The change in pressure is transmitted to the electrical contacts through the pneumatic relay through the capillary.
An electronic safety and control thermostat is a more expensive thermostat for a water heater. The water temperature in the boiler is inversely proportional to the resistance of the electronic sensor. It is by this principle that the temperature of the water heater is controlled and adjusted.
Briefly, the principle of operation of any thermostat can be formulated as follows:
- The required temperature level is set (lever, button, switch).
- The thermostat measures the temperature of the water and turns on the heating (heater), if necessary.
- After the desired temperature is reached, the thermostat breaks the circuit and turns off the heating element.
- As soon as the water cools down, the thermostat for the water heater works again, the circuit closes and the water is heated.
Immersion heating element - heating element
Such elements are a thin tube of copper or steel with a high resistance metal wire and magnesium oxide inside for electrical insulation. It is mounted in the same flange as the thermostat for the water heater and the anode (magnesium). Immersion type elements reliably protected from water ingress, and their operating temperature reaches 300-400 degrees. There are heating elements in shape, power, size. The elements are connected to one or three phases.
Advantages of submersible elements:
- optimal combination of price and quality;
- high efficiency and reliability.
The design of the element is similar to the submersible type, with the only difference being that the body of such a heating element is made of refractory ceramic tubes. Mounted ceramic heating elements in an enameled case with thermostat and anode.
The advantages of such elements:
- quick and convenient replacement of elements in the event of a breakdown, which does not require draining water;
- the enameled coating of the body completely protects against corrosion;
- resistance to scale formation, since the large area of \u200b\u200bthe elements does not allow them to overheat.
One of the most important parts for a water heater is the thermostat. It is the thermostat for the water heater that maintains a constant water temperature, protects against overheating, and, if necessary, performs operations to turn off and turn on the water heater. It is the thermostat that provides the ability to set temperature, and maintain automatic modes.
The basic principles of the thermostat
Each thermostat for a water heater works on the same principle, regardless of the manufacturer. The thermostat is equipped screw design, on which the temperature required by the user is set. After the shut-off valve is screwed in, cold and hot begins to flow into the water heater, after which the adjustment processes begin to work.
To obtain the desired temperature in the water heater, hot water has an advantage. It enters until it reaches the specified parameters, only under this condition does mixing with cold begin. Depending on the type of water heater - instantaneous or storage, the power of the heating element is selected. Most often, it is in flow heaters it has great power.
How to choose the right thermostat
When choosing a heater or optional thermostat installation, remember that the heating tank and the thermostat itself is given different warranty conditions. This is due to the fact that many skilled owners of a water heater, with various types of breakdowns, undertake independent repairs. The most common thermostat failures are:
- copper capillary tube very sensitive to mechanical damage; after it has failed, it cannot be repaired, it should only be replaced with a new one;
- poor adhesion of the electrical connectors of the thermostat and heating element;
- insufficient amount of hot water relative to the total capacity of the water heater may be due to incorrect heating element adjustment;
- too hot water indicates a failure of the thermostat control structure;
- if scale has formed and its amount exceeds the allowable rate, the thermostat will turn on and off very often;
- the failure of the electrical components of the water heater is most often due to constant voltage drops in the network; to ensure the safety of work, it is necessary to install an uninterruptible power supply or a voltage stabilizer.
If you need to replace the thermostat for the water heater, you need to know what types exist:
- Rod thermostat- consists of a steel rod, which is designed to be placed in a heating element tube. Depending on the power and volume of the water heater, the length of the rod thermostat is determined. It ranges from 25 to 45 centimeters.
- Thermostat, which consists of a polyester body. It has a built-in switching device (thermal regulator). Such a device is called capillary. The principle of its operation is based on the volume of expansion fluid in the capillary tube. The expansion fluid acts on the membrane installed in the thermostat and switches the electrical contact.
- There are two types of electronic thermostats: control thermostat and safety thermostat. Their work is arranged in the same way as the work of fuses, which have a certain resistance.
The thermostat for the water heater is exactly the part that is the basis of the entire functioning of the boiler. With properly selected technical characteristics and the fulfillment of all operating conditions, the water heater will last a long time without cleaning and breakdowns.
It can be used both for heating (as part of a radiator) and for providing a home with hot water. The first thing to do when putting it into operation is to protect the system from a possible breakdown of the electric heater, as well as create conditions for its autonomous operation. A popular method for solving this problem is to use a thermostat for a heating element. This small device, also called a thermostat, will 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 - a heating element, and a thermostat. The tubular heater can be submersible and dry. In the first case, it is made of stainless steel and placed inside the tank. Heating of water occurs at direct contact of water with TENOM.
Dry heating elements are made of ceramic, located outside the water tank. Heating of the coolant occurs due to the transfer of thermal energy through the tank wall. Such elements are easy to replace in case of failure.
The thermostat for the heating element is designed to control and maintain the set temperature of the coolant, as well as for emergency shutdown of the 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 a certain type of tubular electric heating element.
Basic principles of work
Regardless of the design and execution, all thermostats operate according to the same scheme. For operation, the thermostat must be built into the tank, and also connected to the heating element. The whole process of temperature control can be divided into 4 stages:
- The toggle switch sets the required temperature range of the coolant.
- The 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 cools down, the whole process is repeated.
It is worth noting that no matter what temperature range you set, the thermostat will turn off the heating element if the water begins to boil. This is necessary to prevent damage to the heating equipment.
During boiling, the process of intensive vaporization begins. As the amount of steam increases, so does the pressure inside the tank. As soon as the pressure value exceeds the critical level, the tank will explode. The thermostat for the heating element does not allow this to happen, 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 temperature of the coolant 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 the temperature is based on the difference in the coefficient of specific thermal expansion of the 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 act on the membrane, which opens the circuit. On cooling, the reverse process occurs.
The operation of electronic thermostats is based on the ability of materials to change their ohmic resistance with a change in temperature. As a result, the voltage in the device increases or decreases, which is registered by special sensors and turn off or turn on the heating element. Electronic instruments are the most complex and expensive, but at the same time the most accurate.
Heating elements with built-in thermostats
The heating element separately from the thermostat is rarely used in practice. As a rule, such a 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 it if it breaks. When choosing devices in this category, you need to pay attention to the following points:
- Housing material. It can be represented by "stainless steel" (the cheapest and most common devices), as well as copper. Copper appliances last longer, but also cost an order of magnitude more expensive.
- Power. For a home electrical network, it is dangerous to choose devices more powerful than 2.5 kW - there is a risk of overload and short circuit. When using more powerful heating elements, lay a separate power cable.
When choosing for a battery, you should not focus on expensive models. Practice shows that the durability of devices does not depend on the price. The service life is determined by the hardness of the water, the loads and the stability of the electrical network.
Spheres of application of heating elements with a thermostat
The scope of application of a heating element with a built-in thermostat is rather narrow, due to high energy consumption and short service life. They are most widely used in water heating equipment. Such a "water tank" is installed in the shower room or in the kitchen and serves as the main or backup source of 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 battery are speed. With the help of such a simple solution, you can very quickly provide a house with a backup source of heat.
Features of heating elements for cast iron batteries
Tubular electric heaters for conventional and cast-iron radiators are practically no different. The only exception is the plug material - 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 buying, make sure that the heating element with a thermostat for cast iron batteries is intended.
thermostats on the market
Thermostats for heating elements can be called consumables. That is why it often goes separately from the heating element. To replace it, you just need to pick up a similar device on the market. To do this, find out:
- Dimensions, type and method of fixing the failed device in the tank.
- The maximum current that the new thermostat will have to handle.
The best option would be to buy the same device that has become unusable. This can be done by contacting the store with a faulty thermostat. In most cases, sellers will pick up the necessary device for you.
We offer to buy a thermostat for a water heater at a low price. Italian quality, long service life, low price, large selection, any delivery. A thermostat for a water heater, another name for a thermostat for a water heater, is used to maintain the set water temperature by turning on / off the heating element (heater) in the water heater. And also for emergency shutdown of the heating element in case of its malfunction. Thermostats are rod and capillary, with thermal protection and without thermal protection. Contacts are provided for the rod thermostat on the heating element flange, as well as a tube into which the thermostat rod is inserted. The average thermostat stem is 27 cm long, but there are thermostats with a 45 cm stem for large volume water heaters. For a capillary thermostat, there is either one tube on the flange of the heating element, or two - for temperature control and thermal protection. It can be sold complete with a heating element and a magnesium anode. The design of the thermostats is made in such a way that you can easily replace the thermostat for the water heater yourself by purchasing it in our online store. At the same time, save money on the services of a master. Any delivery and easy ordering. both on the website, by phone, and in the online help chat.