Magnesium anode for boiler operation: functions and purpose

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Published: 23.11.2019

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Owners of boilers for heating water often come across information about a magnesium anode, but, as a rule, only a few know how the anode looks for a boiler and what role it plays.

In short, it can be noted that the primary task of the magnesium electrode is considered to be the corrosion protection of the inner surfaces of the tank.

Dismantled anode. Photo source: tehnika.expert

• 1 Purpose of the magnesium anode for the water heater
• 2 How it works
• 3 Types of anodes 3.1 Magnesium
• 3.2 Titanium
• 3.3 Aluminum

What is this device?

For the owners of suburban houses, the answer to the often asked question: What is a water heater does not cause any problems. Its appearance resembles a container of a certain size, into which a heating element is mounted. The main task of any such device is to heat the water. Now it is clear that there are several models that can operate on different power supplies. They can be plugged into an outlet, connected to the gas supply.

Water heaters are divided into two types:

The latter have tremendous power and are used in production.

The most widespread are household systems. They differ in their small size and lowest performance. These devices are installed where there is no hot water supply. These are mainly old areas of cities, villages where there is no centralized water supply.

Water heaters are also divided according to the type of fuel:

• Electrical;
• Gas;
• Combined;
• Solid fuel;
• Solar;
• Liquid fuel.

The most common are gas and electrical devices.

What is a magnesium anode in a water heater?

To understand why a magnesium anode for a water heater is needed, you first need to familiarize yourself with the design of the anode. It looks like a narrow rod covered with magnesium alloy. The layer thickness can be up to 15 mm. It is mounted near the heating element. From time to time it is specially installed at the top of the heating tank. The largest diameter of the anode reaches 25 mm, and the length can exceed 600 mm.

The cost of such a magnesium anode is much less than its counterparts.

This is precisely why he gained immense popularity. Of course, knowing the design of the part given for us, you can try to answer the invariable question: what is a magnesium anode in a water heater? The answer lies on the surface.

Principle of operation

The first company to use a magnesium anode was Ariston. It has always been distinguished by the production of high-quality household appliances.

Magnesium is a more active metal than steel. By placing the magnesium anode in the boiler, the water is saturated with the cations of this element. They bind the oxygen formed when the water is heated, thereby protecting the boiler from corrosion.

However, an overabundance of this split element entails the formation of loose scale due to the binding with carbon anions. But it is easy to remove it from the boiler. Scale forms as an insoluble residue and settles on the anode itself.

Purpose of the anode

The main material from which the internal tanks of boilers are made is steel and its alloys. The operating time of the water heater depends on its strength. Oxygen constantly enters the composition of the water, which begins to evolve after heating. Iron walls react with such an oxidizing agent, iron oxide appears or just rust.

Of course, everything is done to secure the walls of the container.

But, unfortunately, they have not yet invented a flawless coating. Huge temperature drops become a prerequisite for the appearance of microcracks, the protective layer begins to pass the oxidizer.

What is the anode in the water heater for? Its functions include protecting the iron surfaces of the boiler from the destructive effects of oxygen. The magnesium anode installed inside the tank is very sensitive to the destructive effect of oxygen, thus extending the life of the water heater.

Anode types

Magnesium anode protection is an electrochemical method. It consists in the fact that the anode is connected to the protected container. At the same time, the metal surface becomes equipotential and an exclusively cathodic process takes place on its areas. The corrosive anodic process is transferred to the magnesium anode.

Magnesium

The magnesium anode for the boiler is made from a conventional threaded rod. It has a metal roller made of silvery metal. During use, the magnesium anode is subject to slow dissolution, until it disappears completely.

At this time, the cathodic protection process stops, and the steel container again corrodes. Manufacturers of popular brands of water heaters recommend replacing the anode every 1.5 years, and in special situations, every 15 months.

Magnesium anode. Photo source: santeh.ks.ua

Anodes are available in different lengths and cross-sectional diameters

Pay attention to this when purchasing a new protective electrode, so that it can be suitable for the desired tank geometry.

Recently, water heaters have been produced in which two anodes are installed. In floor-standing heaters, they are placed on top, and in wall-mounted ones - from below.

Titanium

Modern water heating installations are equipped with a titanium anode, which serves as a special anti-corrosion protection for the surfaces of the inner tank. The service life of such an electrode depends on the quality of the water and is up to 7 years.

The titanium anode is produced with an individual IP and can be used with tanks up to 300 liters. For stable protection for 24 hours, it plugs directly into the socket, while the power consumption for the anode's own needs is very low.

The constant current required for the protective function is set by an external controller. The titanium rod functions as a supply and measurement electrode.

Old and new titanium

When the current supply is switched off for a short time. The anode measures the potential difference, which is compared by the operating program with the initially set potential.

Based on the results obtained, the protective current is established. During operation, such anode does not collapse and therefore does not need to be replaced throughout the entire period of boiler operation.

Aluminum

This is another variant of the protective electrode, coated with an aluminum coating. It is also made in the form of an ordinary threaded rod.

When water is heated, the metal expands, the alloy of the body lengthens, losing its characteristics. Microcracks form on the surface of the tank. After that, the oxygen in the water begins to oxidize the metal, causing irreversible corrosion processes.

The steel body and the electric heating element create a galvanic pair, with the body becoming the anode. In order for it not to collapse under the influence of water, the manufacturers placed an alloy containing aluminum near the heating element.

It takes on the role of the anode - as a result of which all aggressive oxygen is consumed for its oxidation, and the container remains intact. The aluminum anode does not allow the elements of the boiler to oxidize, but it has a very sophisticated design and is easily damaged by mechanical shock.

Operating principle

Imagine that the design of the water heater will not have an anode for the water heater. In this case, there will be an effect that was described back in the 18th century - galvanic steam.

The role of the anode will be made by the boiler body and will begin to collapse, since in the design all the elements used have a greater chemical potential than the body. When installing an anode based on magnesium, all oxidation processes will be expressed on it due to the lowest potential.

Storage water heater design

Usually a magnesium anode is included with every boiler.

Traditionally, we do not consider it because of its secrecy - after all, it seems like a pity to disassemble a new water heater. But if you looked at it exactly when it is new, you could follow a gray rod with a not extremely smooth surface. After a certain time after being used by the boiler, this rod looks like it has been damaged by corrosion. But the walls of the boiler will be intact, which means the anode has fully completed its task.

The question often arises: why specifically magnesium is the basis for such rods? The answer lies in the already mentioned property of metals to have a huge or the least chemical potential.

Magnesium is perfectly suited for the role of anode: it is cheap and helps to take on the role of a victim. In this case, salts do not disappear, but are deposited on its surface.

How to determine if a part needs to be replaced

Magnesium anode to be replaced

Visually and by ear during the use of the boiler, it is possible to determine whether it is time to change the magnesium anode installed inside by the following signs:

• the boiler began to heat up much longer;
• the device is often turned off and on again;
• hot water flowing out of the tap became cloudy, with an unpleasant odor;
• noises are heard during operation of the water heater.

If at least one of the above signs is present, you should think about replacing the magnesium anode - an inexpensive consumable element that can act as a "victim".

Electric water heater or boiler

The food-grade stainless steel, from which the tanks of most water heaters are made, can only withstand hard and salt water for a short time. If steel of suitable properties were used in the manufacture of these devices, then the cost of water heaters would increase manifold, making them unaffordable for almost all buyers.

The tank of any boiler in which the water is heated is not solid, it is most often welded from 2 parts.

After welding, the crystalline network of steel molecules changes due to high temperatures, and specifically in the places of welded seams, such a valuable property of this data as the ability to resist rust disappears.

Despite the fact that the inside of the tank is covered with paint and varnish, it also deteriorates over time, which is facilitated by the expansion of the walls of the tank when the water in it is heated. As a result, microcracks appear, which, when the boiler is drained, rust even faster, coming into contact with oxygen.

Thus, the service life of a water heater is influenced not only by water of disgusting properties, but also by metal manufacturers with different potential.

Features of the

The anode for the water heater is a thick rod made of the same metal as the boiler and installed in the middle of the equipment tank. They fix it very close to the heating element. This is done so that in case of repair or inspection, both the anode and the electrode can be pulled out together. However, there are also models where they are installed separately.

The anode performs two functions at once in the heater. The first purpose, which is considered the main one, is to protect the device and some elements from corrosion.The second purpose is a kind of bonus: it makes the scale on the heating element very loose, which means that it is much easier to remove it from the surface.

The surface of the heating element is polluted mainly by calcium salts and carbonates. The magnesium anode cannot completely protect it from this, but it still makes this problem less dire. When the anode and carbonates interact, magnesium salts are deposited on the heater itself as a result of substitution. They have a very soft texture. Therefore, they can be easily removed mechanically, without even harming the heating element.

Very often, in order to protect the internal surfaces of such structures, special enamel is used when creating.

It significantly extends the service life, and also makes the water heater much safer. Enamelled boilers are considered to be of better quality than their competitors and last longer. These models have several advantages such as:

• the ability to resist decomposition even in water containing nitrogen;
• the coating is inseparable from the metal with which the water heater is finished; due to this, corrosion does not form on the surface;
• the enamel is resistant to sudden changes in temperature.

However, this is still not enough to protect against rust. This is where the anode comes in. It would seem why the anode is in the heater if it has excellent protection even without it. But in any case, the metal will start to rust, especially in the places of welding. Over time, the paint can also become covered with small cracks, and then water through them will get to the metal surface. In this case, destruction will come very quickly. Therefore, without additional protection, such as a magnesium anode, the tank will fail in a few years. As a result of long-term work, traces of corrosion may appear on it, but this is not a big deal, since the tank of the water heater will remain unharmed.

The principle of action of the magnesium anode

If you do not install an anode for a water heater, then such a device will be transformed into a galvanic pair, 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 chemical potential. Installation in the case of the anode with the lowest potential protects the case from destruction.

When buying a boiler, they traditionally do not pay attention to the anode, moreover, it is hidden under the body of the device. It is not an extremely smooth gray rod. Over time, during operation, the anode will begin to look as if it has been damaged by corrosion, and the walls of the case will remain intact. This is the only task of the magnesium anode installed in the water heater.

Magnesium anode

Magnesium is used to coat water heater anodes due to its low cost and low chemical 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 an alloy pin on which a layer of magnesium alloy of 10 to 15 millimeters is applied.

Often, the owners of water heaters are faced with the need to clean the tank from scale and rust, during which the magnesium anode should be replaced. What is this element of the boiler and what role is assigned to it, everyone who has a water heater in the house needs to know.

Photo 1 Magnesium andons for a water heater

Magnesium anode for a water heater: what is it for?

The main m used for the production of internal tanks is stainless steel, which, in turn, is an alloy of iron and carbon.

When heated, the oxygen in the water begins to evolve, interacting with the iron containers of the tank, as a result of which the oxide formation process takes place.

That is why, to protect the inner surface of the water heater, manufacturers use protective enamel, which prolongs the life of the product and makes it safe.

Photo 2 The process of formation of oxide on the anode

There are no ideal ones, therefore, with the constant use of a water heater, temperature drops provoke the appearance of cracks in the protective layer, which leads to the onset of the oxidation process.

To protect the walls from the destructive effects of corrosion, you need to install a special magnesium anode. It is a rod made of stainless steel with a layer of magnesium alloy applied.

The fastening is carried out by means of a threaded part next to the heating device.

Video 1 Removing and cleaning the heating element, replacing the magnesium anode - a step-by-step guide

If we imagine that there is no anode inside the water heater, the process of formation of galvanic vapor begins on the inner surface of the tank, leading to accelerated corrosion and destruction of the tank.

The potential of the inner surface of the tank is much lower than others in the product.

When installing a magnesium anode with a potential limit below the surface of the tank, the main oxidation process falls on it, respectively, the boiler will not begin to rust from the inside.

In other words, in the absence of an anode, its role is played by the tank itself.

If you take an unused anode, which is an internal part of the boiler, it looks like a gray bar with a slightly rough surface. After a certain time of operation of the water heater, traces of corrosive actions appear on the rod, but the tank will remain intact. If, during a routine check of the tank, you noticed that more than 50% of the anode is covered with deep craters, and it itself is crumbling, be sure to replace it with a fresh one, but with all the characteristics of the same being preserved.

Why is the magnesium anode used?

Some are interested in why the magnesium anode is used in water heaters.

The implication is that magnesium has low potential. In addition, magnesium is quite cheap in cost, therefore it is profitable and quite excellent to use it. Upon contact with the magnesium rod, the salt will not disappear, but will simply be deposited on its surface.

Photo 3 Salt deposition on the magnesium anode

In the process of replacing the anode, you should immediately remove scale from the walls of the tank and the heating element, which will significantly extend the operating period of the water heater and significantly improve the quality of the hot water obtained.

Useful Tips

In order for your water heater to be constantly in order and to work for a long time, you should use these recommendations:

• Regardless of how long the boiler is in use, constantly monitor its condition, if an insignificant hissing is heard during its operation, this indicates that the heating element is already covered with scale and requires immediate replacement;
• Salt plaque - it will be in any case, regardless of the property of the water, but when there is too much salt, even the most reliable and high-quality anode cannot cope with it, therefore, you need to inspect more often than once a year;
• From time to time, inspect the anode, or rather the indicator of its wear, the 1st check approximately 6 months after its purchase, and if you find even small traces of its wear, you should replace it;
• If there is no anode in the boiler, it is strictly forbidden to start it up.
  Some, when replacing, often turn on the boiler without putting a fresh element, putting it off until later, but it is worth keeping in mind that the anode is a cheap element, but the consequences of working without it will cost you much more;
• During the change, all water valves must be closed and the power turned off.

Manufacturers of water heaters advise to descale them at least once a year. With active operation, it is possible and more often, since the constant use of boilers leads to the appearance of plaque and scale deposited on the walls of the tank.

Naturally, this leads to a deterioration in the operation of the water heater, while preventive checks and replacement of the magnesium anode will significantly increase the life of the boiler and save money on repairs.

How to clean a water heater and replace a magnesium anode

Considering that over time, the storage water heater becomes covered with limescale, it must be cleaned often (at least once a year and a half). Here we will tell you how to replace the magnesium anode with your own hands.

What are the signs of a contaminated heating element:

• the boiler is often turned on and off;
• barely audible hiss during operation;
• water does not heat up or heats up very slowly.

If the heating element is covered with limescale, more time and, accordingly, electricity is spent on heating the water.

Regardless of which office you have a water heater, the process of cleaning the heating element and removing it, in principle, is not much different.

To begin with, completely disconnect the boiler from the network and shut off the cool water supply. You completely drain it through the cool water supply point.

It is better to connect a hose, as the flow of water will be uncontrolled and flood everything around.

When all the water has been drained, use a Phillips screwdriver to unscrew and remove the protective cover. After removing it, take a picture of the heating element with all the connections, in order to return later everything as it was.

Next, unscrew all the nuts, remove the sensors and the flange. Gently loosen the heating element and take it out. Don't forget to put the bowl down to drain the water.

If the heating element is working, it is quite easy to clean it. To do this, remove the plaque extremely carefully with a flat screwdriver.

When cleaning is carried out often, the plaque does not have time to harden yet and is simply removed, otherwise it will have to be dissolved in citric acid. To do this, dissolve 50 g of citric acid in a liter of water and soak the heating element for a day or two, after which you also remove the plaque with a screwdriver.

After the heating element has been cleaned, unscrew the magnesium anode and insert a new one. The assembly is carried out in the reverse order, connect all the sensors, focusing on the previously made photo. You can check the operation of the heating element only after the boiler has been filled with water and checked if there are any leaks. ...

Ariston water heater malfunctions

Specialists in the repair of Ariston water heaters consider several key nodes to be the most vulnerable:

• Heating element;
• magnesium anode;
• thermostat;
• safety valve;
• control board;
• thermostat;
• o-rings, adapters, switches, gaskets.

Regular inspections of heating elements help to timely identify violations of the integrity of the shell. Read more about the device of different models of Ariston boilers.

The most common defects of Ariston boilers:

• failure of the heating element;
• breakdown of the thermostat;
• decrease in water heating due to the formation of scale;
• leaks due to aging of the gaskets;
• the appearance of corrosion in the storage tank.

Tank leaks in Ariston water heaters are infrequent. The storage tanks are made of stainless steel and covered with protective enamel layers. The cause of breakdown can be metal corrosion, errors in equipment connection or mechanical damage. In Ariston service centers, it is rarely possible to repair it - the masters usually offer a complete replacement of the tank.

Simple repair of Ariston brand water heaters

Regardless of the frequency of operation, each boiler needs periodic cleaning of limescale deposits. Ariston technicians recommend making simple repairs in 1-1.5 years. The low quality of the liquid in the main network forces the maintenance of water heaters much more often.

The reason for urgent descaling may be negative changes in work:

• the appearance of hiss and other atypical sounds during heating;
• frequent switching on and off of the device;
• increase in heating time.

one.De-energize the house and turn off the equipment by disconnecting the wires from the thermostat.

2. Disconnect the hot water pipe. Instead, choose a drain hose with a smaller diameter, which is lowered into a sink or bathtub.

3. Remove the heating element (nut fastening on a metal plate) and pull out the thermostat. To facilitate dismantling, it is recommended to press the flange towards the inside of the heater.

4. In the opened hole, lime deposits will be clearly visible on the walls. They are removed by hand and with a rag moistened with a solution that neutralizes scale.

5. The dismantled elements are installed in their places. The tank is filled with water and the electrical wires are connected.

6. The connection is best done with plastic pipes. They are much more practical and reliable than rubber or metal-plastic hoses.

7. In order not to confuse the contacts (phase and zero), the masters advise using an indicator screwdriver. The circuit drawn on the thermostat also helps to avoid connection errors.

8. Installation of an RCD system (residual current device) in Aristona will protect against electric shock. Its task is to immediately disconnect from the network at the first sign of a short circuit.

9. Inspect the Ariston boiler for leaks. To do this, fill the tank and leave it without switching on for 1-2 hours. If no leaks are found during this time, the water heater can be started.

Specialists in the repair of storage water heaters produced by Ariston categorically do not recommend cleaning with abrasive materials. This negatively affects the interior surfaces of the unit. The descaler can be completely replaced with a citric acid solution. It is enough to pour it into the Ariston boiler tank and leave it for a day.

Before proceeding with the repair of equipment, it is important to accurately identify the cause of the problem. The most common problems encountered during boiler operation are as follows:. the water in the tank began to heat up very slowly; the boiler emits uncharacteristic sounds, which can be expressed in crackling, squeaking and hissing;

The heating element heats the water to a temperature that is higher than the set one; the water does not heat up and remains cold; a container for water intake flows; when the boiler is connected to the mains, the voltage indicator does not light up; the voltage indicator light is on, but the device does not work, since the blocking is triggered; the panel went out control or flashing all lights.

• the water in the tank began to heat up very slowly;
• the boiler emits uncharacteristic sounds, which can be expressed in crackling, squeaking and hissing;
• The heating element heats the water to a temperature that is higher than the set one;
• the water does not heat up and remains cold;
• a container for water intake is flowing;
• when the boiler is connected to the mains, the voltage indicator does not light up;
• the voltage indicator light is on, but the device does not work, as the blocking is triggered;
• the control panel has gone out or all the lights are flashing.

Long-term heating of water is most often associated with the formation of plaque on the heating element. The second reason may be out of order thermostat settings.

Abnormal sounds during operation of the device may be caused by failure of the safety valve. And also extraneous noises can occur if the tank is rusted and leaks, or a lot of scale has accumulated inside.

Strong overheating of the water is associated with a problem in the operation of the thermostat - the element is out of order, or the settings are out of order. If the water does not heat up at all, then the reason is related to the breakdown of the heating element. In the event that the boiler starts to drip, it is first of all recommended to carefully inspect the body of the device, as it could rust. If the tank has leaked from below, this may be due to improper installation of the water heater.

If the control panel or voltage indicator malfunctions, make sure the power cord and socket are not damaged.But also the cause of such malfunctions can be a breakdown of the electronic control board.

During the operation of water heaters, several types of malfunctions can occur:

• heating element burned out, water does not heat up;
• the thermostat has deteriorated;
• the magnesium anode has used up its resource;
• a large layer of scale on the heating element and the inner surface of the boiler.

All these malfunctions, except for replacing the thermostat, require disassembling the water heater. Considering that there is no fundamental difference in connecting Ariston storage water heaters with different capacities and modifications, the disassembly process will be the same.

It can be divided into several stages:

• disconnecting the electrical supply cable;
• draining water from the boiler tank;
• dismantling the flange and directly opening the boiler.

Hot water boilers "Ariston" comply with protection against moisture and dust according to the international scale from IP24 and above. This means that mechanical breakdowns are rare. The design is reliably protected from moisture. Only purposeful vandalism can disable the device.

Important! One of the main design features is the use of an enamel-coated stainless steel protective cover or external thermal protection. ...

The devices use 1-2 heating elements for the main and accelerated heating. As a rule, Ariston boilers are equipped with:

• Silver coated, eco-protection system against microorganisms for water disinfection.
• Enlarged magnesium anode, which helps purify water and protect the tank from corrosion.
• Water distribution system in the tank "Nanomix" and built-in heat pump recirculation.
• Electronic or bimetallic thermostat with temperature control up to 80 degrees.
• Thermal insulation of the outer walls of the tank - polyurethane foam.
• System of protective shutdown and electrical safety.

Ariston water heaters, like other brands, can be repaired by any home craftsman with plumbing experience. Distinctive features of the equipment produced by the Ariston brand are reliability, quality, durability, availability of spare parts. You can buy everything you need in our service center of Ariston "GrayMarket" water heaters.

In our service center, this brand is one of the most common, therefore, we have accumulated a lot of experience in eliminating breakdowns. It is also possible to talk about the vulnerabilities of water heaters of this brand based on the experience of consumers. Most often, sensors fail, heating elements - heating elements, switches, thermostats. Valves and insulating gaskets often break.

We offer you to familiarize yourself with Ozonation of water benefits and harms

What is magnesium anode

The anode is a narrow round rod on which a layer of magnesium alloy 10-15 mm wide is applied.

In the center of this rod there is a threaded rod, with which it is attached next to the heating element. In some versions, the magnesium anode may be located on the top wall of the heating tank. Its diameter ranges from 14-25 mm, length (without threaded rod) ranges from 140 to 660 mm.

Although titanium, zinc and electric anodes are used in boilers, magnesium, due to its own financial availability, remains the most popular option.

The cost

Currently, magnesium anodes are produced and sold, which differ in the length of not only the anode itself, but also the inner stud. The standard length of the purchased anode for hot water equipment can vary in a fairly wide range - 10-60 cm with a stud length of 1.0-23 cm.

Among other things, the anodes differ in terms of the total diameter - 1.4-2.2 cm, and in the diameter of the threaded connection of the stud - "M-4", "M-5", "M-6" and "M-8" ...

The average cost of the most common models of protective magnesium anodes for domestic storage-type boilers:

• 100 mm with D14 20 mm and "M-4" - 200-220 rubles;
• 100 mm with D18 180 mm and "M-6" - 230-250 rubles;
• 100 mm with D18 230 mm and "M-6" - 250-270 rubles;
• 110 mm with D21.3 10 mm and "M-5" - 320-330 rubles;
• 120 mm with D16 10 mm and "M-6" - 150-160 rubles;
• 140 mm with D14 20 mm and "M-4" - 130-140 rubles;
• 145 mm with D25 10 mm and "M-5" - 290-310 rubles;
• 200 mm with D16 35 mm and "M-6" - 280-290 rubles;
• 200 mm with D18 180 mm and "M-6" - 290-310 rubles;
• 200 mm with D16 10 mm and "M-4" - 290-310 rubles;
• 210 mm with D22 10 mm and "M-6" - 360-380 rubles;
• 210 mm with D18 10 mm and "M-4" - 310-320 rubles;
• 230 mm with D22 10 mm and "M-5" - 380-400 rubles;
• 300 mm with D21 10 mm and "M-8" - 440-460 rubles;
• 660 mm with D21.3 13 mm and "M-8" - 810-830 rubles.

Such a noticeable spread in dimensions and cost is not accidental, and makes it easy enough to independently choose the most optimal version of the magnesium anode for hot water devices that differ in length, shape and design characteristics.

Magnesium anode: principle of operation

Now let's take a closer look at the question of why and for what the anode in the water heater is so needed and what is the basic principle of its operation.

The vast majority of internal boiler tanks are made of mild steel.

Magnesium with valence II is the most active alloy than iron with valence III, therefore it binds oxygen formed in water when it is heated, preventing oxygen corrosion of the tank and the iron shell of the heating element. This is the so-called protective protection. This is where the second title of the magnesium anode comes from - anode protector.

An additional task of the anode is to prevent the formation of scale on the heating element. When water is heated, scale appears as a result of precipitated salts of heavy metals.

Due to the overestimated activity of magnesium, they react with it, and not with the iron from which the walls of the tank are made. Therefore, the formation of insoluble calcium carbonate salts is sharply miniaturized, and poorly soluble magnesium salts are converted into a magnesium salt of carbonic acid. Scale, compacted like a stone, becomes loose, separates from the walls of the tank and heating element and settles in flakes to the bottom. You can easily remove soft limescale deposits while cleaning the appliance.

Why do you need an anode

The magnesium anode absorbs most of the limescale and other deposits, protecting the inside of the boiler

To understand why a magnesium anode in water heaters is needed, it will be necessary to consider the very principle of salt deposition (scale formation). The water entering the tank always contains more or less natural (soluble) salts. When heated, they react with the metal of the coating of the coil of the electric heater and parts of the storage tank of the boiler.

The material of the tank, made of corrosion-resistant stainless steel, under the influence of hard water changes its structure over time and gradually deteriorates.

On the other hand, there are metals, the chemical activity of which is so great that they "divert" a significant portion of the reagents to themselves - they include the magnesium necessary for this. The main purpose of an anode based on it is to protect stainless metal surfaces from salt deposits formed as a result of contact with water.

Since limescale deposits and most types of metals have different coefficients of expansion, the heating element will deform over time. The scale formed on it reduces the heat transfer, and the heating of the water slows down. As a result, the useful power delivered to the load drops sharply. When installing an anode in a water heater, it is possible to get rid of all of the above disadvantages and significantly reduce the rate of electricity consumption.

The principle of action of the magnesium anode

All internal elements of the boiler have a different chemical potential, this is what gives the answer to the main question, why the magnesium anode in the boiler is generally needed. Let's take a look at the processes taking place in water heaters in the absence of additional anode protection.

The internal tank of the boiler is most often made of stainless food steel, which has little potential in comparison with all other structural elements (heating element, pipes for water drainage and supply).

It should be borne in mind that the inner tank is made by welding, seamless elements are not used in production due to their overhead.For this reason, the composition of such a tank will not be uniform; within the weld seam, there will be a decrease in resistance to corrosive actions (even when welding is performed in compliance with all technological requirements).

Due to the existing potential difference, the entire structure is the simplest galvanic pair. Therefore, as a result of the ongoing chemical actions, all mineral components of water are deposited on elements with a low potential, that is, on the walls of the inner tank.

Taking into account the reduced corrosion resistance of individual areas (by the way, by and large, even painting the inner surface does not help out), rust damage proceeds even faster. Therefore, the working resource of the boiler is significantly reduced.

Now let's look at the principle of protection with an additional anode. One of the first to use a magnesium anode for the Ariston boiler, a company that has always been considered a manufacturer of high-quality household appliances.

Replacing the magnesium anode in the Ariston boiler

• By itself, magnesium is the most active alloy, if it is associated with steel, including stainless steel. Placing such an element inside the boiler leads to an increase in the content of magnesium cations (Mg2 +) in the water, which take on a role in all chemical processes that occur when water is heated.
• First of all, it is worth noting the fact that magnesium cations are able to perfectly bind the oxygen formed as a result of heating the coolant (water).
  Specifically, thanks to this, additional, rather effective protection against possible corrosion processes is provided.
• In addition, an overabundance of magnesium cations leads to the formation of scale with the least calcium (it is CaCO3 that is an insoluble salt, which leads to the formation of scale deposits on the inner surface of the tank and heating element). Magnesium binds a huge part of the carbon-based anions, therefore, as a result, the scale comes out the most loose, it actually does not settle on the working elements of the boiler, but falls out as an easily removable sediment. All the remaining calcium-based elements are deposited on the surface of the magnesium anode specifically.

Typical breakdowns of Ariston boilers

There are several breakdowns that happen with such water heaters most often. Let's get acquainted with them.

Perhaps the most common instrument malfunction. It happens mainly due to rusting of the internal surfaces. To avoid leakage, Ariston equips its devices with special magnesium anodes - they protect steel from corrosion

But these anodes do not differ in durability, therefore it is so important to change them in a timely manner - this will extend the operating life of the equipment.

Water can also flow from under the gaskets at the pipe joints. In this case, we can assume that you "got off easy", since this kind of breakdown can be easily eliminated. But if the tank itself is leaking, then this is bad, since it is almost impossible to cope with such a breakdown on your own. You do not even need to start brewing defects - this way you will waste your time and nerves. Here (if the warranty period has expired) the only way out is to purchase a new model

When buying, you need to pay special attention to the material from which the tank is made, do not forget about timely maintenance during further use.

Now let's look at other breakdowns that you can get rid of with your own hands.

In this case, the reason is most likely the failure of the heating element itself. Often this kind of "symptoms" arise due to poor electrical connection of the element to the thermostat or, alternatively, problems with the electrical supply in principle. Another heating element can simply become unusable (the procedure for replacing it will be described below).

The main signs are:

• the device is turned on, but the water in it still does not heat up;
• after the tank is connected to the network, the RCD is immediately triggered.

Check valve working principle

Earlier we talked about how a check valve works in a water heater, talked about the most common problems with it and discussed how to avoid its breakdown, in addition to this article, we advise you to read this information

If this is observed with the Ariston boiler, then the reason, probably, lies in the breakdown of the thermostat. Who does not know, a thermostat is necessary in order to maintain the desired temperature, and also to turn off the heating element in case of an emergency. The device, like all other electrical equipment, has its own operational life, therefore at a certain time it must be replaced (this is another procedure included in the repair of Ariston water heaters).

In most cases, the thermostat is located on or near the heating element. It does not touch the water, so there is no need to drain the tank. In principle, everything here is generally much simpler than when replacing the heating element: the panel is removed from the water heater, all wires are disconnected, the thermostat is removed and a new one is installed. It is important that after this the wires are connected correctly.

Note! The new thermostat should be similar to the previous one. Moreover, the replacement procedure must be carried out with the equipment disconnected from the mains!

This sign indicates that a large scale layer has formed on the heating element. If the increased frequency is observed soon after the purchase of the heater, then the Teng in it, most likely, does not correspond to the capacity of the storage tank.

The main "enemy" of any heating element is impurities that stick to its surface and, in fact, create scale. Because of this, not only the duration of heating the water increases, but also the consumption of electricity. In addition, heat energy is poorly dissipated from the surface of the element, as a result of which its temperature exceeds the norm. This causes the boiler to malfunction.

Breakdown No. 5. Anode

It is a tube located inside a water heater (any, not only Ariston brand) and protects the material from corrosion. Often, the anode, as noted above, is installed near the heating element. Who does not know, magnesium is more chemically active than metal, which means that it oxidizes much faster.

Conclusion: the magnesium anode needs to be changed regularly - this will extend the service life of the water heating device.

Different models of boilers have different mounts, so the instructions for replacing the heating element are attached to each one. Before starting to replace the heating element, it is necessary to disconnect the device from the mains. To do this, you need to pull out the plug from the socket, or you can turn off the device using the distribution box.

Before replacing the Teng, it is necessary to drain all the water - for this you need to unscrew the hoses, remove them from the nozzles, then unscrew the check valve.

To prevent water from spilling onto the floor, it is important not to forget to substitute a container that will collect the liquid. The next step is to remove the protective plastic cover (in each model it has a different location)

If the cover is equipped with a light bulb, it must be carefully detached.

To disassemble the Ariston boiler, you need to use a wrench

How to change the heating element:

• You can disassemble the device, in which the nut is located in the center and holds the metal bar, using a special key for 13. Unscrew the nut and remove the corner. The flange must be inserted inward and turned sideways in the tank, then pushed down.
• If there are 5 or more nuts around the washer, you must first pull out the thermostat. The nuts are unscrewed and the flange is pulled down.

If the heating element in the water heater is dry, then you need to start disconnecting the wires, after which you should pull out several heating elements. If the heating element is replaced at home, it is important to monitor the correctness of the actions, since the device can be easily damaged. Each type of device has its own instructions, which can be easily found on the Internet.

Detaching the flange

In all modifications of Ariston water heaters, the cover - flange - has an oval shape. A heating element, a magnesium anode and a tube for the thermostat are installed on this flange.

A rubber gasket is placed on the flange around the perimeter. The flange is fastened with a U-bar on one nut.

By unscrewing this nut, you can push the flange into the boiler with a little effort, then, turning it, pull it out. That's it - the disassembly of the water heater is over.

You can start cleaning the heating element, replacing the magnesium anode, and cleaning the inner surface of the tank from scale.

Experts recommend: do not use excessive force when cleaning the tank. its wall becomes thinner over time due to corrosion, and it is better not to touch a thin layer of scale.

Cleaning the heating element of the water heater

It is necessary to remove all the debris accumulated in the boiler, clean the heating element from scale and replace the magnesium anode. Many advise replacing the gasket after a year or two, however, if it has not lost its elasticity and strength, you can leave it alone - moreover, it is not so easy to get it and it is expensive.

We offer you to familiarize yourself with How to change a toilet bowl with your own hands: dismantling the old one and replacing it with a new one

After all the maintenance work, you can start assembling in the reverse order.

The operation of water heaters provides for their regular maintenance and disassembly to replace the heating element, magnesium anode, and clean the inner surface of the boiler.

All work on the installation and disassembly of the Ariston boiler, with certain skills and tools, can be performed by each person without special qualifications.

Modern heaters are capable of self-diagnostics and, in the event of a malfunction, display an error code on the screen or highlight a specific indicator if the model does not have a screen (the highlighted indicator is indicated in parentheses). Below are the error codes of Ariston water heaters and their description.

The beginning of the disassembly of the Ariston water heater

Despite the fact that the Italian company has been the world leader in the production of water heating equipment for more than a quarter of a century, given the quality of our water and the parameters of the power grid, breakdowns are also characteristic of such reliable equipment.

Here, the weak points of the steel: a tubular heating element, a check valve and a magnesium anode.

However, these are fairly simple breakdowns and they can be easily eliminated with your own hands at home with a minimum set of "garage" tools.

The Ariston storage tanks themselves have a fairly simple internal arrangement for repair or maintenance.

First of all, check the power supply to your storage water heater

Pay attention to the condition of the outlet, whether it is burnt or melted, this can happen due to inadequate parameters of the outlet and the power of the device.

Why specifically magnesium

The use of this alloy is primarily based on its affordability.

So, a magnesium anode for an Electrolux boiler can be purchased for 250-300 rubles, while the cost of other unique components is incommensurably higher.

In addition, despite its highest activity, the magnesium anode has a significant work resource. Depending on the hardness of the water used, its service life can reach 2-4 years.

Well, the main reason lies specifically in obtaining with the help of such an anode an easily removable scale based on magnesium cations, the use of other metals does not give the same effect.

Anode design and types

In hot water storage equipment, characterized by tanks made of common metals, the installation of magnesium or so-called "sacrificial" anodes is strictly mandatory. The appearance of such elements may vary.

For example, conventional pendant water heaters are most often equipped with anodes that have the appearance of a conventional rod, with a threaded rod installed in the inside. Depending on the design features of the boiler, the stud may differ not only in diameter, but also in length.

Magnesium anode and heating element assembly

In floor-standing gas or electric water-heating equipment with a large storage tank, large-sized "sacrificial" anodes are installed, which may somewhat complicate their independent replacement. For example, in boilers with a height of two meters, most often, meter protective magnesium anodes of a multisection type are installed.

A novelty is flexible plastic anodes, which are plastic tubes with special microscopic pores. The interior of the structure is filled with special magnesium granules.

New anode - bottom and anodes after operation

The main advantage of flexible anodes is the complete absence of sediment, represented by oxidized magnesium. Among other things, as the use progresses, magnesium powder is added, which reduces the cost of purchasing a new protective element and its replacement.

Protective magnesium anodes, installed inside any storage-type water-heating equipment, are most often represented by a steel rod, very abundantly covered with a layer based on a magnesium alloy.

Disinfecting magnesium anode: what is this element for?

The use of a water heater is carried out in a wide variety of buildings.

In particular:

• Cottages;
• Apartment buildings;
• Hospitals and beyond.

The purpose of the water heater is completely clear, because it is required so that there is always burning water in the room, regardless of whether there are seasonal outages or not.

Not enough who knows about how the device works and the fact that without such a small part, like a magnesium anode, operation is impossible.

The anode is required so that it "takes" on itself various salts that are contained in the water, which excludes the formation of corrosion inside the boiler tank.

It is worth seeing that even if the tank is made one hundred percent of stainless steel, over time and under the influence of salts in the water, it will begin to rust.

Disinfecting magnesium anode eliminates the formation of corrosion inside the boiler tank

There are 2 completely logical and proven explanations for this:

1. Food grade stainless steel does not have the same parameters as highly resistant c.
   To be more precise, the stainless steel can resist the influence of salt and hard water, but only on condition that the action is not constant and very short in time.
2. The tank installed in the water heater is not an integral part, but a container welded from 2 or a pair of parts. Where the weld is located, under the action of salts, a change in the crystal lattices and molecules of the stainless steel begins, which contributes to a decrease in the technical features of this metal.

Some people think that since the inside of the tank is painted, then there is nothing to worry about, but any paint and varnish coatings lose their durability over time, especially when in an environment with constantly fluctuating temperatures.

At the time of heating, the walls of the tank expand, as well as the stretching of the coating from the inside, which violates its integrity

Why Magnesium

This question worries many people. The secret lies in the electrochemical potential. For this element, it is very low. At the same time, the price of this metal makes it possible to use it in industrial volumes, while not overstating the price of a boiler.

Using it as a consumable is much more profitable than sacrificing capacity. The versatility of certain types of modern electrodes makes it possible to put them on units of various modifications, for example, Ariston, Electrolux and other popular models. Similarly, they are suitable for the Russian-assembled Termeks electric water heater and for indirect heating boilers.

List of sources

• stroy-podskazka.ru
• kotle.ru
• DomEkonom.su
• proffservice64.ru
• foundmaster.ru
• TechnoSova.ru
• StrojDvor.ru

• Author: Sergey
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What is the purpose of installing a magnesium anode for a water heater in a house

What functions does a magnesium rod have in a water heater?

First of all, it is worth seeing that it is needed for:

• In order to extend the life of the boiler;
• Obtaining salt-free water;
• Ensure that the water heater is not clogged and broken.

It is worth seeing that the magnesium anode is cheap in cost, and this is a big plus, since it is in general availability.

The purpose of the product is quite common, because it does not kill salt compounds, but attracts them to itself.

It looks like a pin, on which it is applied from a magnesium alloy, 15 mm wide, which prevents the boiler from rusting.

The magnesium (non-magnetic) anode and the boiler serve for a long time, but if you pay attention to a number of tips presented below, you can significantly extend the life of the water heater.

Magnesium anode is used to purify water from salts

Recommendations:

1. The condition of the boiler must be monitored at all times, regardless of how long ago it was acquired.
   In particular, if there is a typical hiss, then this indicates the presence of scale on the anode.
2. In any case, the appearance of salt deposits is unrealistic to exclude. The rate of plaque formation depends, first of all, on the hardness of the water, and secondly, with a large number of them, even anodes of the highest quality will not be able to withstand the opposition.
3. It is strictly forbidden to use a water heater if an anode is not installed in it, even if it is made of super-alloys that do not corrode.
   An extremely big mistake is pulling out the anode at the end of its service life, and starting the apparatus without it. A boiler without such a part will not last much, and after a breakdown, you will have to take new equipment, which is much more expensive than one part.

That is why it is necessary from time to time to inspect the product and inspect the magnesium anode for wear. The first time it is necessary to inspect it approximately six months after the start of operation and, if necessary, replace it.

How to increase the life of the device

By following simple rules, you can significantly extend the life of the electric heating tank

1. The presence of noises during the operation of the product indicates the formation of a large amount of scale inside the device case, respectively, it is necessary to clean it.
2. The presence of a filter in the supply system to the boiler of cold water significantly reduces the concentration of impurities settling on surfaces.
3. If, upon visual inspection of the anode, it was found that it was worn out by at least 50%, the moment is approaching to replace it.
4. You should not start up the boiler after removing the old rod, but even before installing a new one, since all impurities in the absence of a magnesium anode will settle on the heating element, the inner walls of the container.
5. The boiler cleaning procedure should be carried out at least once a year.

As for the last point, in the case of intensive use of water heating equipment, experts recommend changing the magnesium anode more often than once a year. At the same time, you should also carefully inspect all internal surfaces of the boiler for the presence of harmful bacteria on them. The latter does not affect the operation of the equipment to a greater extent: the accumulated pathogens can cause serious harm to everyone who uses water from the heating tank.

Taking into account the above information, one can easily draw the following conclusion: timely replacement of the anode is a guarantee of long-term uninterrupted operation of the device and saving money that can be spent on expensive repairs of the product.

Replacing the heating element, if we are not talking about a dry heating element, in a water heater is a rather laborious work and requires a certain procedure. This order does not differ greatly from one manufacturer to another, nevertheless, there are some specific features. Let's consider how to change the heating element on the Thermex boiler.

Replacing the magnesium anode for a water heater in the house

The anode in the water heater is important.

He:

• Inexpensive;
• You can simply find a replacement;
• You can replace it yourself.

When is it necessary to change the protective element that prevents corrosion of the tank?

This is required in the absence of the heating element.

Replacing the magnesium anode is quite easy to do yourself.

In this case, you need:

• You need to purchase an anode in a special service center, for example, Ariston, Atlantic, Termex or Gorenje;
• Be sure to take a check;
• When returning home, take out an old rod;
• If its remains are in the cavity where it is installed, then their complete removal is required;
• Next, a spotless ten is installed;
• A fresh anode is installed nearby;
• A water heater is being assembled;

The equipment is connected to the network when all the components are dry inside, in an unpleasant case, there may be a short circuit.

The process of dismantling the old and installing a new rod

The process of replacing the magnesium anode in the Drazhitsa boiler and other manufacturers is quite simple. Anyone can remove the old anode from the water heater and install a new one in its place, even without special skills. But when carrying out this procedure, it should be borne in mind that each manufacturer has its own modification, respectively, it is worth buying only the original component. Therefore, in this regard, it is better to give preference to visiting a service center or a specialized outlet.

The procedure consists of several intermediate stages. The first step is to disconnect the boiler from the electrical network and drain all the liquid from it. A check valve will help speed up this procedure, but it would be wise to pre-connect the hose so as not to splatter everything around.

Draining water from the boiler

In the next step, we unscrew the casing, which is located at the bottom of the tank.The thermal sensor and flange are then visible. The last two are also subject to dismantling.

Further actions: the heating element is pulled out by light staggering. Due to the fact that the heating element is covered with salt deposits, some difficulties may arise at this stage, therefore, it is necessary to act carefully in order to avoid damage to the part.

The next step is to dismantle the old anode, which is located next to the heating element. Often, only an empty pin is found, which is a vivid demonstration of the destruction of magnesium. In any case, the part must be removed from the socket.

Details: how a magnesium anode works in a water heater and why

What is the purpose of a magnesium anode for a water heater, it became most clear, but how does it work?

This does not require:

• Conduct independent experiments;
• Call a specialist;
• Explore a variety of literature.

It is enough to remember a couple of lessons in chemistry.

With the assistance of the iron from which the tank is made, with oxygen, iron oxide is formed.

In other words, metal oxidation begins.

Magnesium anode can prevent the boiler from breaking

By installing the magnesium part inside the tank, the manufacturers aimed to achieve 2 goals:

1. Magnesium has the best ability to donate atoms as opposed to iron.
   In other words, iron does not have time to start interacting with oxygen, since there is a magnesium anode. Specifically, it prevents the formation of corrosion on the inside of the tank, since magnesium reacts, not iron.
2. It is worth seeing that tap water is rich not only in oxygen, but also in dissolved calcium salts, which are deposited in the form of scale on the parts installed inside the water heater. When the scale interacts with the heating element, it is converted into a calcium stone, which lowers the thermal conductivity of the heater, and the result is a breakdown of the heating element.

   

   Specifically in this situation, the magnesium anode helps, it prevents from breakdown, because its electrons displace calcium ions, turning the scale not into solid salts, but into a loose substance.

It is worth seeing that due to such a complex work, the anode can quickly collapse, and therefore it requires constant replacement.

Tips

It is worth adhering to such tips from experts as:

• to prolong the life of the heater, you need to monitor its operation. If a hissing sound is heard during water intake, this means that scale has appeared on the heater, so you urgently need to clean the boiler;
• it is imperative to install water filters, which largely reduce the concentration of various impurities deposited on the parts;
• it is necessary to look at the condition of the anode. If it is already half worn out, then it will soon need to be replaced;
• when the old anode is removed, and the new one has not yet been installed, you should not start the water heater so that different deposits do not appear on the heating element. After all, buying a new boiler will cost many times more than the anode itself;
• very frequent use of the water heater contributes to the appearance of scale, therefore, the tank should be cleaned once a year, or even more often;
• it is worth remembering that although stainless steel is a fairly durable material and can withstand hard water and salt impurities, it is still possible for a while. Protection will last literally a year and a half. Therefore, it is better to buy a water heater with a magnesium anode that will cope with all the problems.

Many developers are thinking about improving the protective layer in a water heater.

However, this does not progress further. After all, the cost of such products will be sky-high. People simply won't be able to buy them, so manufacturers keep making water heaters with anodes. Magnesium in this case is needed, because it not only has the ability to attract salt to itself and prevent it from settling on important structural elements, but also has a small electrochemical potential.

But it's not worth shifting all the blame for the poor quality of protection only to the developers. Not only they are responsible for the breakdown of water heaters. In many regions of the country, the chemical composition of water is very far from ideal. And it, as you know, has constant interaction not only with the walls of the heater, but also with the heating elements themselves. This is why a magnesium anode is needed.

Having studied all the information about anodes for water heaters, you can choose the right one, taking into account the size of this structure.

The choice of purchase depends on the decision of the owner. You can buy a water heater with a magnesium anode and change it occasionally. Or buy a boiler with a titanium coated anode and forget about its existence.

For information on how to replace the anode, see the next video.

How and what to replace the magnesium anode in a water heater without consequences

What is a magnesium anode, and how it looks, has already been clarified. Almost everyone has a question about whether this part can be replaced with another or homemade one. Why not, for example, install an ordinary electrode, the composition of which is identical to the anode? In fact, the magnesium anode is a part specially made for this process, and no matter which office a boiler, for example, Ariston, it is a must.

To replace it, you will need to prepare:

• Hose;
• Capacities;
• A set of keys;
• Anode;
• Knife;
• Cleaning agent.

It is necessary to carry out the work in stages so as not to harm the water heater, heating element and anode.

To replace the magnesium anode, you need to prepare the tools

Stages:

• The boiler is de-energized.
• The cover is removed, and the wiring is disconnected.
• The water supply must be shut off.
• The water is drained from the tank by putting a hose on the drain valve and lowering it into the bathroom.
• The valve opens.
  It will take about 30 minutes to drain.
• It is necessary to remove the boiler from the wall.
• Turn and dismantle the heating element.
• Pull it out by grasping the electrical part.
• It is especially important not to deform the rubber gasket.
• If the anode installed on the heating element is damaged, then it is necessary to remove one hundred percent, both the remnants and the pin.
• The heating element is cleared.
• A fresh anode is mounted.
• The water heater is being assembled in the reverse order.

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