Many people have heard that water heaters of various brands, including Ariston, contain a magnesium anode, but not everyone understands what it is and what it is needed for. The internal elements of this device, which heats water, are constantly subjected to heavy loads and destructive physical and chemical effects.

Magnesium anode serves as a kind of airbag for a metal tank, taking on any chemical influence and preventing the formation of corrosion. This extends the service life of the container. Let's take a closer look at what a magnesium anode for an Ariston boiler is and how it can be replaced if it breaks.

The occurrence of corrosion

Since modern water heaters of the brands Ariston, Electrolux, Thermex and others are made of stainless steel, many people have a question about where this could come from. corrosion. There are two factors that can negate all the advantages of stainless steel in boilers.

First of all, food grade stainless steel is not very resistant material. It can withstand hard and salty water, but only for a limited time, no more than a year. If truly high-quality stainless steel were used to make boilers, then the cost of such devices would be prohibitive and only a few would be able to afford them. But such water heaters are affordable for many people and provide hot water in almost every home.

The second factor is that the design of the tank of water heaters of various brands, including Ariston, lack of integrity. Typically the tank consists of two elements welded together. Quite often, welded areas change their structure under the influence of temperature, and stainless steel loses its protective functions. This is how corrosion occurs.

Many people know that the surfaces of boilers are painted special compounds aimed at protection against corrosion. But they also cannot be called durable. In addition, the temperature and environment inside the heater changes all the time. At first it's cold there, then it's very hot. In this case, the metal constantly expands and contracts. Under the influence of this factor, protective coatings also stretch and collapse.

Why is a magnesium anode needed in a water heater?

If there is no anode inside the boiler, then there will be galvanic couple. This phenomenon was first described in the eighteenth century. The body will serve as a protector against corrosion, as a result of which after some time it will begin to collapse. This is explained by the fact that the electrochemical potential of the housing will be much lower than that of the materials used in the device.

When installing a magnesium anode for a water heater, all oxidation processes will be directed towards it due to the lower potential. This element is steel rod, which is coated with a thick layer of magnesium alloy. The anode inside the water heater tank is fixed thanks to the threaded part and is usually located near the heating element. After use, traces of corrosion appear on this rod. But the main thing is that the tank itself remains intact.

Replacing the magnesium anode in a water heater

During operation, the magnesium anode for water heaters of various brands, including Ariston, can quickly collapse, so it should be changed periodically. If you do not do this, the service life of the device will depend on the following factors:

• thickness and material of the walls of the container;
• condition of the internal coating;
• water quality;
• temperature conditions.

The anode for water heaters from Ariston and other companies requires replacement if its wear is more than 60%. This usually happens through every 15–18 months of operation. During the replacement process, the main difficulty is that the length of the anode is equal to the size of the tank. Before replacing it, it is necessary to clarify whether the distance under the device will be sufficient for installation.

Electrochemical corrosion destroys the metal of the anode - a special protective coating made of zinc, or an electrode made of magnesium, aluminum or the same zinc. In the absence of a protective electrode, the metal of the welded seams of the water heater tank will act as an anode and will be destroyed.

Tap water with salts dissolved in it is a conductor electric current- electrolyte. From a school physics course we know that if two electrodes made of different metals are placed in an electrolyte, a galvanic cell is formed. One of the electrodes receives a positive potential - the anode, the other - a negative potential - the cathode. As a result of an electrochemical reaction in the electrolyte, the anode metal interacts with oxygen dissolved in water. The anode metal is destroyed and turns into oxides and rust. The second electrode is the cathode and does not corrode.

The water heater tank always contains parts made of different metals - the tank is made of steel, the heating element is made of copper. The copper in this pair will be the cathode, and the steel tank will be the anode.

Even if all the parts in the tank are made of stainless steel, the welds have differences in the composition of the metal. Very small impurities on the surface of the weld metal form a galvanic element with the tank metal and create conditions for electrochemical corrosion of the weld metal. The weld metal in this galvanic cell is the anode and will gradually deteriorate.

To protect the metal of the tank and the weld from electrochemical corrosion, an electrode made of metal with a high negative potential is placed in the electrolyte. Such an electrode will have anode potential, both with the metal of the steel tank and the weld. And the protected metal will act as a cathode. As a result, the anode metal will corrode and slowly deteriorate, and the cathode metal (tank and welds) will not suffer from rust.

This method of protection is called tread protection against corrosion, and the electrode is called a sacrificial anode. It is sometimes advantageous to make an anode in the form of covering one metal with another. For example, steel is often coated with a layer of zinc to create galvanized steel. A layer of zinc in which serves as the anode.

The following basic requirements apply to the metal used as a tread material:

• The electrode potential of the protector material must be significantly more negative than the potential of the metal being protected;
• The amount of electricity obtained from the electrochemical dissolution of a unit mass of the protector should be as large as possible.

These requirements for tread protection of steel and copper parts are best met, and electrodes made of magnesium, aluminum or zinc are most often used. Zinc ions, Zn 2+, are toxic. Therefore, for sanitary reasons, galvanized steel and zinc anodes are not used in water heaters.

To protect steel tanks of electric water heaters from corrosion, their manufacturers usually Magnesium anodes are used. Aluminum electrodes create a smaller potential difference with other metals in the electrolyte than magnesium anodes. You can find aluminum anodes for water heaters from third-party manufacturers on the market.

Table. Some electrochemical properties of magnesium and aluminum

Anode electrodes are made from special alloys of the base metal. The formation of a dense oxide film prevents the passage of current in commercially pure aluminum and conventional technical metal alloys. The introduction of special additives into alloys makes it possible to obtain electrodes with potentials that are more negative than those of the base metal. Alloy protectors remain active, corrode uniformly, and do not become passive in the environment in which they are used.

The magnesium anode may contain some percentage of aluminum, and zinc and magnesium are necessarily added to the aluminum electrode alloy. In addition, to improve properties, other elements, such as rare earth indium, are often added to the metal composition. U For each manufacturer, the composition and properties of anodes may be different.

Each protector has its own radius of protective action, which depends both on the size and properties of the anode, and on the parameters of the electrolyte and the metal being protected. The dimensions of the anode, as well as the number of electrodes in the tank, are selected depending on the surface area of ​​the metal being protected and the presence of electrical insulating coatings (paint, glass enamel, etc.) on its surface. The larger the surface of open, without protective coatings, metal in the tank, the larger the anode dimensions and/or their number should be.

The rate of destruction and erosion of the anode also depends on the composition of the electrode metal and the electrical conductivity of water. Magnesium protectors should be used in water with a pH of 9.5 – 10.5. If the pH of the water is lower, the dissolution rate of the magnesium electrode increases. When choosing an anode, I recommend following the instructions in the factory instructions.

All metal parts in the water heater tank must have electrical contact with the anode. You cannot simply put the anode in the tank, or press it with plastic ties to the sensor tubes, as some “experts” advise.

Disadvantages of anodic sacrificial protection against corrosion

If the shift in the anode potential to the negative side exceeds a certain value, the so-called redefense, which leads to hydrogen release on the cathode, to changes in the composition of the near-electrode layer and to other processes. All these processes contribute to the peeling of the protective (insulating) coating in the tank and accelerate the corrosion of the protected metal.

To eliminate overprotection and prevent underprotection, the magnitude of the potential difference between the anode and cathode must be within certain limits depending on a number of factors that may vary. Moreover, in the case of a significant change in these factors, it is necessary to change the value of the anode potential. That is, The magnitude of the potential difference between the anode and cathode must be measured, monitored and adjusted.

High-price water heaters use more advanced, adjustable cathodic corrosion protection. The potential shift of the protected metal object is carried out using an external source DC. The potential difference between the titanium anode and the water heater tank is regulated electronically according to a given program.

The practice of operating budget water heaters with sacrificial protection indicates that it is not always possible to eliminate overprotection by using a magnesium anode recommended by the manufacturer.

For a simple, protective way to protect water heaters, the only way to prevent overprotection and reduce potential is to replace the magnesium anode onto an aluminum electrode.

When to change a magnesium anode to an aluminum one

The fact that the magnesium anode in the water heater operates in overprotection mode is indicated by the presence of two factors simultaneously:

• The magnesium electrode dissolves quickly; it needs to be replaced more often than once every two years.
• Intense hydrogen release. Gas accumulates at the top of the boiler and when the tap is opened, hot water, especially at the very beginning, gurgles. The release of hydrogen sometimes causes the water to smell like hydrogen sulfide (more on this at the end of the article).

When to change the boiler sacrificial anode

After a year of operation, corrosion is visible on the surface of the magnesium anode - oxides, which crumble and gradually dissolve, destroy the electrode. As a result, the length and diameter of the anode decreased.

As erosion progresses, anodes must be replaced regularly. The criteria by which the need to replace the anode is determined are usually specified in the factory instructions. Manufacturers of electric water heaters recommend that after one year from the start of operation, inspect and assess the degree of wear of the anode and the amount of scale deposits on the heating elements. Based on the assessment results, the frequency of anode replacement and descaling is determined.

The sacrificial protection anode has a slight effect on the formation of scale on the heating elements of the water heater. An increase in the intensity of electrochemical processes on the metal surface contributes to some loosening of the scale layer. Stone made from hardness salts becomes less dense and is easier to separate from the metal.

Water + anode = hydrogen sulfide

Why does hot water from a boiler smell like hydrogen sulfide?

After some time, the water from the boiler may begin to smell terribly of hydrogen sulfide. The reason is the proliferation of bacteria in the water heater tank. This happens especially often if water is supplied to the water supply from a local well or well. Water from the city water supply is usually specially prepared, highly disinfected, chlorinated, and such cases rarely occur with it.

Large amounts of hydrogen sulfide gas (H 2 S) are released and accumulated as a result of the activity of sulfate-reducing (sulfate-reducing) bacteria in water.

Sulfate-reducing bacteria use organic matter (CH 2 O) or hydrogen (H) as an electron donor and sulfate (SO 4) as an electron acceptor when receiving energy

2CH 2 O + SO 4 2- + 2H + => 2CO 2 + H2S+ 2H 2 O

Simply put, there are two types of sulfate-reducing bacteria. Both varieties require sulfates - sulfur compounds - as well as hydrogen to survive. But one type of bacteria extracts hydrogen from organic matter in sludge. Other bacteria use molecular hydrogen which is found in water.

Important - the development of sulfate-reducing bacteria occurs under anaerobic conditions, in the absence of free oxygen in water.

Sulfates are salts of sulfuric acid H 2 SO 4, for example, potassium sulfate K 2 SO 4, sodium hydrogen sulfate NaHSO 4. Sulfates are widespread in nature, forming a whole group of minerals. Many sulfates are soluble in water and are found in natural water.

Why is hydrogen sulfide dangerous?

Hydrogen sulfide (H 2 S) is poorly soluble in water. Flammable. The concentration limits of ignition in a mixture with air are 4.5-45% hydrogen sulfide.

Hydrogen sulfide is very toxic. Inhaling air with a small content of hydrogen sulfide causes dizziness, headache, nausea, and with a significant concentration it leads to coma, convulsions, pulmonary edema and even death. At high concentrations, a single inhalation can cause instant death. When inhaling air with small concentrations, a person quickly adapts to unpleasant smell“rotten eggs” and it ceases to be felt. A sweetish metallic taste appears in the mouth.

When inhaling air with a high concentration, due to paralysis of the olfactory nerve, the smell of hydrogen sulfide almost immediately ceases to be felt. Hydrogen sulfide is also used in medicinal purposes, for example in hydrogen sulfide baths.

The appearance of hydrogen sulfide in boiler water is not only bad smell and health hazard. A solution of hydrogen sulfide in water is a very weak hydrogen sulfide acid. Hydrogen sulfide turns water in the boiler tank into acid, albeit a very weak one. An increase in water acidity accelerates the electrochemical dissolution of the magnesium anode for sacrificial corrosion protection.

Two reasons for the smell of hydrogen sulfide from boiler water

One reason for the smell

The nutrient medium for some varieties of sulfate-reducing bacteria is sludge, which contains organic compounds. Such bacteria can be found in nature, for example, in silt deposits at the bottom of swamps and lakes. Or in artificial structures - in a sewer septic tank, for example. Or at the bottom of a well, or a storage tank with water, if organic contaminants accumulate there.

In the boiler tank, over time, a layer of sludge settles and accumulates from the water, which can become a habitat for sulfate-reducing bacteria.

Increase the water temperature in the boiler to maximum, above 70 o C and use it hot water three days. Microorganisms should die at this temperature, and the hydrogen sulfide accumulated in the sludge will leave the tank with water during this time. If the smell of hydrogen sulfide has disappeared, then most likely the cause of the smell is the activity of bacteria that live in the sludge layer.

Another reason for the smell

Other types of bacteria live in water. For vital activity, such bacteria molecular hydrogen required. Some of them live in natural thermal water sources at a temperature of +110 o C.

In the water heater tank, molecular hydrogen is released especially intensively if the protective corrosion protection operates in the “overprotection” mode (read more about “overprotection” in the article above).

If the water in the water heater tank contains enough large number sulfates, and the protective protection works in the “overprotection” mode, with intense hydrogen release, then conditions are created for the active proliferation of sulfate-reducing bacteria in the water.

Determining the cause is not difficult - remove the sacrificial anode from the tank and turn on the water heater without the anode. If the water no longer smells like rotten eggs, the reason has been found.

Ways to eliminate the smell of hydrogen sulfide from boiler water

In the water heater tank, sulfate-reducing bacteria may be present in both the sludge and water at the same time. But usually, one type of bacteria is the most active. Depending on what type of sulfate-reducing bacteria in the boiler tank is causing the smell of hydrogen sulfide, the method of getting rid of the smell is chosen.

Eliminating bacteria that live in the sludge layer

It may be enough to do at least one of the following:

• The easiest way is to raise the water temperature above 70 o C o C o C.
• Regularly clean the boiler to remove scale and sludge deposits on the bottom.
• Take measures to reduce the amount of organic contaminants in tap water. To do this, you can change the water intake horizon - instead of a well, take water from a well or deepen the well. Install filters to purify tap water from mechanical and organic contaminants.

Eliminating bacteria from boiler water

To suppress sulfate-reducing bacteria living in boiler water, it is often enough to do the following:

• Try raising the water temperature above 70 o C and use this water for three days until the smell disappears. In the future, constantly keep the water temperature in the boiler above 55 o C. It is recommended to periodically increase the temperature above 70 o C. But this method does not always help. Bacteria living in boiler water are often resistant to these temperatures.
• The activity of sulfate-reducing bacteria is suppressed if the molecular hydrogen content in water is reduced. For this purpose, the operating mode of the tread protection is optimized. Replacing a magnesium anode with an aluminum one eliminates “overprotection,” which reduces the hydrogen content in water. Read about replacing anodes at the beginning of this article.

General measures to combat bacteria in the boiler

The following measures can suppress the development of bacteria in both water and sludge:

• Aeration, saturation with air, of tap water leads to an increase in the content of free oxygen in the water. As a result, the anaerobic habitat of bacteria changes to one less favorable for their life.
• Disinfect tap water using methods whose antibacterial effect persists for a long time after treatment - chlorination, etc. Ultraviolet water treatment is not suitable for this.
• Take measures to reduce the amount of soluble sulfur compounds in tap water. To do this, you can change the water intake horizon - instead of a well, take water from a well or deepen the well. These measures should be selected after testing the water source for sulfate content.

The boiler is constantly in contact with water. And the main danger for a water heater is rust and corrosion. If in the old days people dipped a silver coin into the water so that the water would retain its properties longer and not spoil, then for modern boilers a special anode is used.

Why do you need a magnesium anode for a water heater? The photo gives a clear answer. This special rod is installed inside the device body. It prevents the formation of rust and extends the life of the water heater.

Unlike silver, which destroyed bacteria in the water, a special magnesium anode for the water heater removes salts from the water, thereby preventing corrosion from developing in the internal tank of the device. The fight against rust is always relevant: despite the fact that they are made of stainless steel, corrosion continues to do its job.

The seemingly eternal stainless steel is affected by at least two factors that completely dispel the myth of its extraordinary durability.

Electric water heater or boiler

The material most water heater tanks are made from can only withstand hard and salty water for a short time. If steel of the proper quality were used in the manufacture of these devices, then the price of water heaters would increase many times over, making them inaccessible to many buyers.

The tank of any boiler in which water is heated is not solid; it is most often welded from two parts. After welding crystal lattice The molecules of steel change due to high temperatures, and it is in the places of welds that such a valuable property of this material as the ability to resist rust is lost.

Although the inside of the tank is covered paint coating, over time it also collapses, which is facilitated by the expansion of the walls of the tank when the water in it heats up. As a result, microcracks appear, which, when the boiler is drained, rust even faster when they come into contact with oxygen.

Thus, the service life of a water heater is affected not only by poor quality water, but also by the use of metals with different potentials by manufacturers.

Operating principle of magnesium anode

If you do not install an anode for a water heater, then such a device will turn into a galvanic couple, described by scientists back in the 18th century. Instead of the anode, the boiler body will begin to work and, accordingly, it will begin to collapse, since the other elements used in it have a greater electrochemical potential. Installing an anode with a lower potential into the housing protects the housing from destruction.

When buying a boiler, people usually don’t pay attention to the anode; moreover, it is hidden under the body of the device. It is a not very smooth grayish rod. Over time, during operation, the anode will begin to look corroded, but the walls of the housing will remain intact. This is the only task of the magnesium anode installed in the water heater.

Magnesium anode

Magnesium is used to coat anodes for water heaters due to its low price and low electrochemical potential. The salts that are released from the water thanks to the anode do not actually disappear anywhere, but settle on its surface.

Thus, the anode is simply a metal pin on which a layer of 10 to 15 millimeters is applied.

Symptoms of a problem

When operating a water heater, it is useful to periodically listen to the sounds it makes. If there is a hissing sound when heating the water, most likely, plaque has appeared on the heating elements, and it is advisable to clean the device from scale and mineral salts.

Even with high purity of the water used, salts are always present in it, only in varying degrees of concentration. Even the anode, if the water contains excessive salts, will not be able to completely cope with them. Therefore, when using water with a high salt content, it is recommended to use various filters and water softeners.

Despite the apparent simplicity of the water heater and the presence of a magnesium anode in its body, only in practice can you understand when it’s time to look inside the boiler and clean it. If destruction of the magnesium anode for a water heater is detected, which requires a visual inspection, then based on the condition of the pin, one can guess how much time it has left to work effectively. It is better to replace it with a new one immediately, without waiting until it is completely destroyed and the boiler is left without protection.

For self-replacement The anode does not require special tools, and anyone can do the job. The only thing that should not be neglected is compliance with safety precautions.

As a rule, cleaning the water heater is required after a year of operation, but for preventive purposes it can be done earlier.

By removing deposits from the heating elements or from the bottom of the tank, as well as checking and changing the anode for the water heater if necessary, you can significantly extend the life of the device.

Many people have heard about a magnesium anode for a water heater, but not everyone knows what it is, what it is for, and what it looks like in the photo. Let's try to understand in more detail and answer several important and significant questions. Basically, the job of a magnesium anode is to fight against salt coming from the water. Thus, the element prevents such an unpleasant process as corrosion inside the boiler.

• 1 Occurrence of corrosion
• 2 Wine producers
• 3 How an anode works
  • 3.1 Why magnesium?
• 4 Useful tips

The occurrence of corrosion

Many will say that water heaters are now made of stainless steel, where does corrosion come from? This is true; tanks are most often made from this material. However, two factors, at least two, can negate any theoretical corrosion resistance of stainless steel when used in household appliances. That is, in boilers as well.

1. First of all, food grade stainless steel is far from a highly resistant material. In theory, it can withstand salty and hard water, but only for a certain time. A few months, a year, but no more. If boilers were truly made from high-quality stainless steel, their cost would be prohibitive, and only a few would be able to afford them. And now a water heater is an affordable device that provides hot water in almost every home.
2. The second factor is the lack of integrity of the water heater tank design. As a rule, the tank consists of two elements welded together. Under the influence of temperature, welding sites often change their structure; once stainless steel loses these functions. This is where corrosion occurs.

It is no secret that surfaces are painted with special compounds, which are also aimed at protecting against corrosion. However, they cannot be called durable. In addition, the environment and temperature inside the heater are constantly changing. At first it is cold, then very hot. As a result, the metal expands and contracts. Under the influence of this factor, protective coatings stretch and collapse. Nothing lasts forever.

Wine producers

In principle, it would be fair to blame the manufacturers of these devices for the poor corrosion resistance of heaters. As soon as microcracks form in the tank, the process becomes irreversible. An intense oxidation process begins as the interaction with oxygen has increased.

Electrochemical potential tables clearly state what will happen and how to avoid it. But manufacturers don’t pay much attention to this. The manufacturer, due to savings or a simple misunderstanding of chemistry, uses various metals in the production of heaters. They cannot withstand the load, and the boilers fail.

Blaming the manufacturers alone is also not entirely fair. The quality of the water leaves much to be desired, but this is what the boiler has to process.

How an anode works

Let's imagine for a moment that there is no anode inside the boiler. In this case, a galvanic couple will arise. This effect was first described in the distant eighteenth century. The housing will play the role of a protector against corrosion, as a result of which its destruction will soon begin. And all because the electrochemical potential of the housing is lower than that of the materials used in the design.

If you install an anode, this potential will be less than that of the body. Consequently, the oxidative process will be directed towards it.

A magnesium anode is usually part of the design of any boiler. If you look at a brand new element, it will have a not entirely smooth surface on the rod gray. After use in the boiler, traces of corrosion will appear on the rod. But the most important thing is that the tank itself will remain intact.

Why magnesium?

This question is asked by many people. It's all about electrochemical potential. Magnesium is low. Plus, the material is quite affordable from a financial point of view, which is why assigning the function of self-sacrifice to it is quite profitable and effective. The salt will not disappear upon contact with the anode, but will simply be deposited on its surface.

So, a magnesium anode for a water heater is a pin on which a magnesium alloy 10-15 millimeters thick is applied, and serves to protect the boiler from corrosion.

1. Keep an eye on the condition of your boiler, no matter how long ago you bought it. The hissing sound during its operation indicates that the heating element, that is, heating element, is covered with scale and needs repair or replacement.
2. Salt coating. Whatever one may say, plaque will appear to one degree or another. It all depends on the quality of the water. When there are too many salts, even the most efficient anode may not be able to cope with them.
3. Periodically it is worth looking inside the water heater and checking the degree of wear of the magnesium anode. About six months after purchase, take a first look and note how worn the anode is. If it's about 50 percent, be sure to change it after six months. Although even if it’s half worn out, it won’t be a bad idea to replace it.
4. Do not put your boiler into operation unless it has an anode installed. In some cases, they may pull it out and not install a new one, because there is no time to go to the store or there is not enough free time for repairs. Then the boiler is turned on without the anode. This item is quite cheap, finding it is not a problem. This will be much cheaper than later eliminating the consequences of operating a water heater without an anode.
5. It is not necessary to call a technician to remove and insert a new magnesium anode. No special skills or special tools are required. The main thing here is to follow safety precautions. All water valves must be turned off and the power from the outlet must be turned off.
6. All manufacturers recommend descaling boilers every year. Some do this even more often, which is quite the right decision. Active use of water heaters leads to the formation of scale and deposits that settle at the bottom of the tank. This impairs the performance of the device. Timely cleaning and checking the condition of the magnesium anode will significantly extend the life of the water heater and eliminate unnecessary financial costs for its repair.

As you understand, the role of the magnesium anode in any modern boiler is incredibly important. Essentially, this small rod provides the feed clean water, extends the life of the water heater itself and sacrifices itself for our benefit. Our task is to monitor its condition and promptly replace it with a new anode. As a result, even a not very expensive boiler can last for many years.

Domestic water heaters are our salvation and source of comfort: at any time of the year, regardless of heating season, we can enjoy hot water. But, like any device, these devices require preventive maintenance and repair. And since they are used quite actively, they need to be repaired and cleaned often: once a year. Sometimes after the next inspection you are told that you need to change the anode. What is it and why change it? Let's figure it out.

When water is heated, a process of oxidation and destruction occurs. inner surface tank. Most water heaters are produced with iron tanks, sometimes they are coated inside with enamel, sometimes they are made of stainless steel. But in any case, water finds its way to the metal: through microcracks in the enamel or through a seam in stainless steel (under the influence of high temperatures during welding, most of the properties are lost). Oxidation occurs, salt deposits accumulate, and the metal rusts. This can lead to destruction of the integrity of the tank.

In order to make the process less active, manufacturers use a magnesium anode. For the water heater, it becomes a kind of antivirus. The magnesium contained in this device reacts more actively with the oxygen contained in the water than iron. The main part of the salts dissolved in water settles on the anode, and the salts are more loose and easier to clean. So, a magnesium anode for a water heater is a way to protect the tank from scale formation and destruction. If you do not have this device, you can install it yourself.

Magnesium anode for water heater: types

Most often, these devices are made in the form of a metal rod, on one side of which there is a special threaded pin. 10-15 mm is applied to the surface of the pin. Usually it is installed next to the heating element, but sometimes manufacturers place it in a different place.

Magnesium comes in different diameters and lengths, but it is advisable to replace one that has become unusable with a similar one. For example, there is a special magnesium anode “Termex”, which is installed in water heaters of this brand. In some cases, you can try to install a longer or thicker pin, but only in cases where there is room for this. But here, too, there are exceptions: the Ariston company recommends installing a magnesium anode only of its own production and only of the size that was included in the kit.

IN lately Some new models have appeared that can be installed in any tanks. For example, in low rooms it is problematic to install a meter-long anode in a large container (the height of the tank is 1.2-1.7 meters, plus a pin more than a meter long). In this case, it is convenient to install multi-section models. Such anodes consist of several short elements, movably fastened together. Quite convenient, although it requires certain installation skills.

Recently, a flexible plastic anode has appeared on the market. It consists of a hollow with microscopic pores, into which magnesium granules are poured. Its first advantage: the absence of oxidized magnesium, which usually settles in the tank. Its second advantage is the ability to add powder during operation (it is sold separately).