The anode for the water heater is magnesium and titanium. What is it needed for? Sacrificial electrode in a boiler: functions, maintenance Protective anode
Sooner or later, any owner of this device will have to replace a burnt-out heating element in a storage electric boiler. Don’t think that it will serve you for decades, no matter how high-quality and expensive the model is.
Heating elements fail for two reasons:
- scale formation and burnout of the working element (heating coil)
- corrosion and mechanical failure
Scale and cleaning of heating elements
Scale forms primarily in the presence of hard water. Just 1mm of scale gives 75% additional thermal insulation. Thus, the heating element under such a large layer of salts simply begins to overheat.
The first sign of scale formation is a distinct hissing or whistling noise.
When the noises become louder, but the boiler continues to work properly, do not delay cleaning, otherwise it may be too late. 
Disassemble the boiler, as shown below, and begin cleaning. This can be done in two ways:
Cut off the neck plastic bottle 1.5 l and dilute the solution in it:
- warm water 60 degrees
- 7 teaspoons citric acid
Soak the heating element in it overnight. After which, in the morning you clean off all excess. The result is sometimes simply amazing. 
Corrosion of the water heating element
Why does the heating element body corrode and collapse? The fact is that the heating element in the boiler is equipped with a magnesium anode. 
Without it, a galvanic couple is formed inside the titanium:
- tank - heating element
And with a magnesium anode:
- heating element - anode
Through this anode, all stray currents flow to the ground, gradually taking with them some part of the anode body. When it is completely destroyed, these currents begin to flow down the body of the heating element. 
The growths on the heating element do not form evenly. Because of this different areas its copper shell acquires different expansion coefficients. As a result, surface tension is created, which breaks the shell of the heating element. 
In many service centers, in the event of a major breakdown of the boiler, you may even be denied a warranty if there is no receipt for timely replacement of the anode.
Ultimately, corrosion becomes through and the working element burns out.
By the way, with the anode intact, the water from the tank may have a slight odor. When the smell disappears, this may be some kind of sign of corrosion of the electrode.
Modern models have special sensors that monitor the condition of the anode. 
With timely replacement of the anode and mandatory cleaning, your heating element will actually last several times longer. Grounding the housing also increases the service life of the heating element by at least two times. 
However, for some reason many people lose sight of this point. Meanwhile, during intensive work, it is recommended to clean the boiler at least once a year.
It cannot be said with certainty that some models, for example Electrolux, Ariston or Gorenje, have a longer service life than Thermex or Indesit. It all depends on many factors:
- amount of water consumed
- the average heating temperature of this water, its chemical composition
- is there grounding or not?
Checking the serviceability of the heating element
How can you understand that the heating element has burned out and it’s time to change it? If the indicator lights light up and show that the boiler is on, but it does not heat, this is only an indirect reason. 
You can also check the presence of potential between zero and the body of the device. When the heating element is destroyed, its current-carrying spiral comes into contact with water, and through it the voltage reaches the boiler body. 
It is better to take measurements with a multimeter in AC voltage measurement mode. The dial can show either a couple of tens of volts or all 220V. This already indicates a 100% malfunction and the need to change the heating element. 
If you have an RCD, as it should be in a normal circuit, then it starts to knock out when you try to turn on and supply power. 
The correct RCD (not 30mA, but max 10mA) is required element circuits when connecting any boiler, otherwise you could easily find voltage on the faucet, tap water in the kitchen and in other unexpected places. 
Draining water and disassembling the water heater
And so, when you decide that you still need to open it, the first thing you do is turn off the power by unplugging the plug from the socket. Then drain the water from the titanium. To do this, turn off the hot and cold water supply taps. 
Unscrew the cold water hose, placing a suitable container for drainage.
If water does not flow from the removed hose, this indicates air lock. We need to remove it. To do this, just slightly loosen the nut at the connection point of the pipe. hot water to the pipe. 
After draining, completely unscrew both valves from the titanium (hot + cold) to open the bottom cover and gain access to the heating elements. 
There are modern models where the bottom cover is collapsible and to remove it, it is not necessary to touch the valve. It comes in the form of a plastic insert secured with several screws. 
Disconnect the power wires, first remembering or marking with a marker which one is connected where. Better yet, draw a diagram. As a rule, all wires are colored and this will be easy to do. Otherwise, you can get confused in such a pile of wiring. 
If you don’t want to draw anything, then just take a couple of photos on your cell phone. You will know exactly the location of all elements and wires. 
After this, unscrew the nuts or screws securing the heating element itself around the perimeter.
You can unscrew them in any order, but you need to screw them in the same way as the engine head or the wheels on a car, that is, crosswise.
If you immediately tighten a nut all the way, this will cause the flange to bend and there will not be the required tightness. Consequently, the gasket will not hold and will leak.
Carefully pull the heating element out. It will be all covered in rust, and from the magnesium anode, except for a thin burnt piece of iron, there may be nothing left at all. 
Flushing
After the heating elements are removed, the boiler itself must be washed clean water from all the rust and dirt that has accumulated inside. Therefore, for a quality replacement, the water heater still has to be removed from the wall. 
Rinse the inside with a regular tap hose. Pour only a little water, since the boiler with a volume of 50-80 liters will still have to be lifted manually to drain all the scraps. Some people add citric acid when washing, others don’t.
Washing tip: It is best to rinse the tank in the bathroom, placing it vertically on a linen board. Twist the watering can from the mixer shower and insert the hose into the hole where the heating element was.
Replacing heating element and anode
After all cleaning procedures, proceed to reassembly. Keep in mind that the anode may not be included with the new heating element. Be sure to buy it separately and screw it into your seat.
It is especially worth noting that if two heating elements are installed in the boiler, then it is not always necessary to install two anodes.
One is enough for one electric titanium, even if you have at least five heating elements inside. The anode is not an accessory or component of the heating element. This is an element of protection for the boiler. 
Please note that in the factory version, during the first disassembly, on the second heating element there is no place at all for mounting this anode. 
Some claim that on tanks with stainless steel you can do without an anode, the main thing is to have them in specimens with walls made of glass porcelain. 
However, the pattern of failure of boilers is usually the same: first the anode, then the heating element and then the housing.
You can install heating elements not only from the direct manufacturer of the boiler. For example, there is a company called Thermowatt, which produces some of the best heating elements on the market. The main thing is to match the power dimensions and a seat. 
Practice has shown that there is not much difference. The main thing here is the quality of the product (China or Italy). 
When repairing, be sure to change the flange gasket. Here are some of their varieties for boilers Thermex, Ariston, Indesit, Gorenje, Electrolux:
Thermex Ariston Indesit Gorenje Electrolux
Some people are trying to save money here. Remove the old one and replace it with the new element.
However, a leak that will inevitably form in a month or two will make you regret such savings.
The flange nuts, as mentioned above, are tightened in a cross pattern. In this case, there is no need to use excessive force; you can inadvertently break the thread or tear the pin out of the body. 
According to the marks sketched on the diagram, connect the power wires and put them in place protective cover-cover. Before closing the cover, be sure to check all terminal blocks again, they should fit tightly and not loosen.
Filling with water and checking functionality
Hang the electric titanium in place. Connect the hoses and open cold water, start filling the tank. The hot water tap must also be open to allow air to escape.
At the same time, make sure that there are no leaks anywhere. As soon as water comes out of the “hot” tap, the boiler is full. There is no need to close the tap immediately; let all the “slurry” spill out and finally flush the tank and pipes. 
Only when it goes pure water, turn off the mixer.
After this, the water heater must stand for at least half an hour or an hour so that condensation leaves all surfaces and there is confidence that there are no leaks. 
You can then apply voltage by plugging the titanium into an outlet. To check the operation of the thermostat, use the control knob to force the adjustment to maximum and minimum.
In this case, the boiler on/off light should light up.
If the boiler operates quietly, without making any sounds, and it is not clear to you whether it is heating or not, you can check the energy consumption using the meter.
At maximum heating power of the heater, the counter will spin or blink much faster. This means that the heating elements work as they should.
The entire repair with the purchase of spare parts will cost you around 1500-2000 rubles. In any workshop calling a plumber to your home, for such work they will ask for at least 3000-5000 rubles, and this does not include materials.
So do-it-yourself repair can save you a significant amount of money, the main thing is not to make some mistakes.
Errors when replacing heating elements
1 Tighten the heating element fastening nuts in a circle.
As discussed in this article, this method will lead to bending of the flange and subsequent leakage. That is, you will have to remove the boiler from the wall again, unscrew everything and reassemble it again.
2 Application of sealant when installing the gasket.
No sealants should be used when replacing heating elements. Tightness should be created only by uniform pressing of the gasket material.
3 Using an old gasket.
No matter how intact it may seem, in any case, every time you open the heating elements, be sure to replace the sealing elements.
4 Replacing only the heating element without replacing the magnesium anode.Even if you don’t find a suitable anode in your store, never install heating elements inside the tank without it. Not only does this reduce the service life of the heating elements, but ultimately it all ends in burning out the body of the boiler tank. 
True, some expensive boiler models have titanium anodes with electronic potential removal. 
They just don't require replacement. Therefore, before unscrewing anything, carefully study the product data sheet.
5 Control board.
When washing the tank and draining the water, be very careful; you can accidentally flood the electronic control board with the display, which is located on the side of the housing, with water. In this case, the boiler simply will not start after switching on.
You will search for the cause for a long time, ringing all the terminals, but it will lie literally on the surface. You can soak this board even with the boiler upside down. 
Look closely at the hole where the lone control wire goes. 
Water can simply flow through it directly to the electronics. So, it is best to close this hole initially, even before pulling out the heating elements, by pushing any seal there.
Now almost every house and apartment has water heaters and boilers. And, of course, any owner, making such a purchase, hopes that the device will serve for a long time.
In order for the water heater to work well, it is very important to monitor its condition. One of the most important details is a magnesium anode. In this article we will look at what this part is intended for in a water heater, how it works and why you can’t do without it.
This part is coated with a magnesium alloy, inside of which there is a metal base with threads for attaching the anode. It is designed to protect the walls of the tank from rust and scale.
When working electric water heater The magnesium rod is subject to corrosion, the extent of which depends on the quality of the water and the frequency of use of the tank. If it is destroyed, it is easily replaced with another. Experts advise replacing the anode once a year. To understand how often to do this, you need to monitor the condition of the anode.
The principle of operation of this element is that magnesium is more active than iron, so it is the first to be destroyed. Most of the dirt that is cleaned out of the tank is the remains of the anode.
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Although electric water heaters are made of stainless material, they are susceptible to corrosion. Often the steel is not the best highest quality, plus water hardness and quality play a big role. When the first small cracks appear inside the boiler, corrosion occurs, and nothing can be done about it. But if a magnesium anode is working in the water heater, then it can resolve the situation.
Causes of corrosion:
- Stainless steel is unable to withstand hard water.
- The boiler consists of two elements that are welded together; due to this effect, the stainless steel loses its properties.
Some Thermex boilers have a glass-ceramic coating, which bad water can't do much harm.
In boilers indirect heating can be installed to combat corrosion cathodic protection, but it runs on electricity and must be connected separately.
The magnesium-coated rod prevents corrosion inside the boiler. This part also softens scale on the heating element, that is, it protects the water heater from damage.
Now the magnesium anode is sold together with the water heater. Even if the boiler is made from the most expensive of stainless steel, With various coatings, the presence of this element is simply necessary, as it helps the device last longer and protects it from breakdowns.
The rod degrades over time, but how long it lasts is affected by the severity of the water.
If the water heater does not have a magnesium anode, its destruction by corrosion begins, and if it is present, the entire oxidation process is directed precisely at this rod.
Now you will find out why you need a magnesium and titanium anode in a water heater (boiler). We will also consider how to replace the anode with your own hands.
It often happens that the owners of water heaters have time to clean the tank from scale and corrosion and need to replace the anode. But what an anode is, man does not know. From the article you will learn what it is and in general why it is needed in a water heater.
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Water heater anode
First, let's understand that the anode is a boiler element in the form of a thick metal rod (magnesium or titanium).
The main material used for the production of internal tanks is stainless steel (an alloy of iron and carbon). Heated oxygen, being in the water, begins to be released and interacts with the capacity of the steel tank. After this, the formation of oxide begins.
For the purpose of protection inner surface Protective enamel is used in the water heating structure. It makes the service life longer and at the same time safer.
The advantages that enamel coating provides are the following:
- resists decay in any water, even sea water or containing nitrogen compounds;
- inseparable from the metal, and this prevents the formation of corrosion under the coating;
- does not age, it is wear-resistant;
- enamel is resistant to temperature changes;
- non-toxic and hygienic;
- enamel is biologically neutral (it is not the best environment for bacteria to grow);
- The coating technology is such that it is possible to apply enamel in containers of any size.
To prevent rust from appearing on the tank, anodes are installed - magnesium or titanium. They are fastened using a threaded part with a heating device.
What is it needed for
Let's try to figure out why a magnesium anode is needed for a water heater.
Current flows from the anode itself to the damaged areas. Thus, due to the decomposition of the more active material, corrosion does not occur.
The anode, which is built into the tank, consists almost entirely of magnesium, so it is enough to check the structure once a year. It is necessary to comply with the check, since due to poor quality water the service life of the product may be reduced.
Magnesium and iron come into contact with water, but magnesium is more reactive than steel. Magnesium atoms leave the anode and produce oxide. Thus, the steel atoms remain intact and the tank does not corrode. That's the whole principle of its operation.
Magnesium anode for a water heater has a low price, and its use will be quite effective. When interacting with such a rod, the salt will not disappear, but will simply remain on its surface.
Titanium coated (active anode)
The operation of a titanium coated anode is slightly different. In this case, the current is supplied by a voltage source from outside. A stable current, which is needed to prevent corrosion, is supplied and regulated by an external electronically controlled. The active anode functions as a supply and measuring electrode.
From time to time the current supply stops. During these minutes, the anode analyzes the state of the internal part of the structure for damage, and accurately regulates the strength of the current supply for restoration.
When a water heater with a titanium anode operates, it is not subject to destruction, and therefore does not need to be replaced throughout the entire life of the water heater.
On sale you can find a titanium anode with external power supply Austria Email. Model: CORREX. It costs a lot - more than 15,000 rubles.
Replacing the magnesium anode
You already know how often you need to change the anode in a water heater: titanium does not require replacement during all the time of use, but magnesium should be checked on average once a year. If you use the device frequently - more than once a year.
New and corroded anode
During the replacement process, it is also worth removing scale from the inner surface of the tank and the heating element. This will extend the life of the heating device and improve the quality of the water.
Now let's look at how to change the magnesium anode in a water heater with your own hands. It doesn’t matter which manufacturer’s device you purchased, the cleaning process will not be radically different.
It is worth saying that replacing the anode in a water heater should occur if there are the following signs of a dirty tubular electric heater:
- the boiler turns on and off more often;
- there is a slight hiss during operation;
- the water takes a long time to heat up, or does not heat up at all (after all, if it is covered with a coating of lime, then it takes more time and electrical energy to heat the liquid).
With your own hands
To replace the anode, the following work is required:
- It is worth disconnecting the boiler from the power supply and shutting off the flow of cold water. Drain completely through the water supply point (it is recommended to connect a hose, since the water flow will be difficult to control and there is a possibility of flooding everything around).
- The next step is to unscrew and remove the protective cover. It's better to take a photo after removing it a heating element with all the connections, so that after all the work you don’t get confused and restore the structure to its original form.
- Then you need to unscrew all the nuts, remove the sensors, the flange and begin to carefully loosen the tubular electric heater. After you take it out, place a bowl where the water will drain.
- The heating element in working condition is easier to clean, since the coating has not yet hardened and can be easily removed flat screwdriver. If the plaque nevertheless becomes hard, then it is dissolved in citric acid(50 grams of citric acid per liter of water - keep in solution for about two days).
- After all the cleaning work has been completed, you need to unscrew the magnesium anode for the water heater and insert a new one. Assembly must be done in reverse order.
Now you know that you need to monitor the condition of the anode in the water heater and change it on time.
Hi all! I want to tell you about such a specific thing as replacing the magnesium anode in a water heater. The specific model for 80 liters is Termex 80YS-RE. But in principle, the dimensions can fit many others. Anyone interested, welcome to the laboratory :-))) Lots of bad photos
I'll probably start with how I decided to open my water heater (after it had served faithfully for about 3 years) for cleaning.
A little theory
Why do you need a magnesium anode? To protect the water heater tank from corrosion. Increases the service life of the water heater. With timely replacement of a worn-out (min. 30%) magnesium anode, the water heater will last 20-30 years, without an anode - 1-3 years.
Operating principle: if two metals are placed in water, then one of them, namely the more active Magnesium, will begin to emit electrons and attach hydroxyl groups (OH) from the water to the resulting ions, and the other, less active Iron, will accept electrons, attaching them to its ions. As a result, the more active metal - the anode - will be oxidized, and the less active metal - the cathode (water heater tank) - will be reduced. Thus, the anode will protect the tank from corrosion.
It's a pity I didn't take a photo when I first opened the tank. I scooped out almost half a basin of scale flakes and sand-like deposits. An autopsy showed that the anode urgently needed to be replaced. Having rummaged through the expanses of the local “Belarusian Internet”, I saw a price of about $12 per piece. I decided to try my luck on Ali. But there wasn’t one of each, but there were large ones, but 5 each for almost the same price, but three. The toad still won, and thinking that this stub would last another month, I put the unit back together. Having made the order, I sat down to wait at the window, I rejoiced at my economy - “that’s three for the price of one”
And so, less than six months later, 26 days later, I received the coveted package.
It looks like nothing, but we’ll check. Here's what's on the site:
But in real life:
And now the decoding of the black box of bad photos: Length - 190 mm, “body” diameter - 16 mm, shank diameter - 5 mm. In general, the Chinese did not fit into any of the sizes, plus or minus a kilometer. Moreover, there is also a thread on the shank (it’s a pity not 6 mm, which is needed). The composition corresponds and was tested in a nearby laboratory, by making an explosive package of a cute sparkler. Having said hello to the seller, through a dispute and having recovered some of the money for new reagents, I got to work.
Crazy Hands™
1. Disconnect the boiler from the network and shut off the water supply to the tank, and start draining the water:
2. First, let’s unscrew check valve from cold water (supply):
We screw the hose back, and unscrew the other end of the hose from the supply and throw it into the bathtub, toilet, container, etc. or like I have on the mixer.
3. Open the tap with cold water and unscrew the hose from hot water from the tank (create a vacuum):
While we are going to taste the new reagents, drink tea, coffee, juice, kefir, whatever you like, the process of draining by gravity is not quick.
4. After a while we come and admire the result:
5. We begin to open the patient. In the hole on the right under the plug there is a Phillips screw:
“MO-O-O-ZGI-I-I!” 
6. Carefully cut out the brain, disconnect everything and unscrew the fastenings of the wiring (don’t forget to capture for posterity or for the service department :-) how everything was in order to put it back together):
With these temperature sensors, be careful: they are on capillary copper tubes; they should not be squeezed or bent too much:
7. Well, we got to the heart iron man unscrew all the nuts in a circle (the remaining water will flow out, you need to substitute a container):
The insides are torn apart (you can sanitize the abdominal cavity, clean the tank from the inside - a thin hand will get through (hello to my wife)):
Not a lot of dirt in a month.
8. We begin transplantation of a Chinese donor organ. BEFORE:
AFTER:
9. Putting it back together (and if everything worked out, move on to step 10):
10. Enjoy the result))))):
PY.SY. There are too few photos, I have them:
Owners of boiler water heaters often come across references to a magnesium anode. But not everyone knows what this part is, what its function is and why a magnesium anode is needed in a boiler.
Let's figure out how this element works and how to know if it's time to replace your magnesium anode for your water heater.
Corrosion becomes a problem during the operation of a water heating tank. internal walls. Because of this, after some time the equipment fails. To understand why an anode is needed in a home water heater, let’s consider what happens to the boiler during operation.
Causes of corrosion of a water heating tank
- Weak anti-corrosion coating of the material
Modern boiler tanks are made of stainless steel, which should reliably protect the mechanism, which is constantly in contact with water, from corrosion. However, high-quality grades of stainless steel are expensive and are not profitable to use in mass production.
Such water heaters would become a luxury for many people. To establish flow output and make water heating products accessible, food grade stainless steel is used. But this type of steel has a less durable coating and begins to gradually fail after three to four months.
- Metal deformation during operation
Water heating devices are constantly in a changing state. The hot liquid acts on the metal, causing it to expand, after which the walls contract again.
In addition, devices, as a rule, consist of two parts that fit tightly together at the joint. Temperatures and high blood pressure affect this seam. In all these cases, the integrity of the stainless coating is compromised, microcracks appear in the material, and it is less resistant to corrosion.
- Savings on production
Some manufacturers are not interested in their products lasting long. Only industrial equipment withstands heavy loads and prolonged use.
Home tanks are made from cheap alloys with the expectation that people will change them frequently. Naturally, this approach is beneficial to the manufacturer - and completely uncomfortable for users. Conscientious brands produce products with optimized quality at low cost of water heaters.
- Water quality
Another negative factor is water hardness. In some regions, the quality of the water supply is so poor that water heating tanks become clogged with salt deposits within a few months, which prevents the normal use of the boiler.
Because of heavy metals Scale settles on the walls of the tank and heating element, which destroys the metal.
For these reasons, heaters are improved, and the shock is directed away from the central parts of the device. To do this, use a magnesium anode for the boiler.
How does the anode work in a water heater and what is it for?
The magnesium anode in the water heater is metal cylinder, made of the named material, which is designed to attract heavy salts from water in order to increase the life of the device.
This is a consumable item and needs to be changed periodically. This part wears out so that the rest of the housing and heater continue to function properly.
The walls of the heater deteriorate because the electrochemical potential of the material is lower than that of the other components used in the assembly. Therefore, without an anode, scale salts settle precisely on the inner layer of the tank, corroding the surface. The potential of magnesium is even lower.
The inner insert attracts destructive sediment towards itself. Here's how an installed magnesium anode works in a water heater.
Of all the metals that can provide such protection against corrosion, magnesium is the most accessible. It is used in production without raising the price of the finished product. At the same time, periodic replacement of such a part will cost the owners inexpensively.
How to replace the anode in a water heating tank
This part must be replaced regularly as the metal deteriorates over time. During such reassembly, it will not hurt to descale the heating element.
If the replacement was not made on time and the magnesium anode for the water heater has completely “dissolved,” corrosion will begin to attack the tank.
Replacing the anode on a boiler is easy; even an inexperienced user can do it. To do this you need to follow several steps:
- Shut off the water supply. Unscrew the cold water supply hose and drain the remaining liquid from the tank. For this purpose, an outlet tube is used.
- After this, you need to remove the protective casing and remove the heating element and other internal elements. Sometimes after prolonged use metal parts difficult to dismantle. If the heating element is stuck, apply some force, but act carefully so as not to damage the mechanism. Rock the rod from side to side.
- Then the anode is removed. Don't be surprised if after prolonged use all that's left is the base.
- After installation new part It is advisable to descale the device and then assemble it.
Ideally, the anode should be replaced approximately once every 12 months. This is a fairly economical procedure, considering the benefits of the device. Often the service life of a part depends on its thickness, the characteristics of the tank and the hardness of the water in your area, so check the water heater periodically.
Which anode to choose for replacement in the boiler
Today on the market of parts and components for plumbing you can purchase copper or aluminum anode. In the majority modern models a magnesium rod is installed because it has best characteristics. These columns differ from each other in thickness and height.
Typically, the parameters of the anode depend on the type, shape and volume of the boiler and are selected taking into account these parameters in order to serve effectively for as long as possible.
When choosing an anode for foreign-made water heaters, it is better to take with you an old dismantled rod to purchase the appropriate type. If this is not possible, ask a consultant for help by naming the brand of your water heating tank.
That is why it is better to buy components for the boiler in specialized stores - if not branded stores, then at least professional ones, or from a service center. Such centers employ competent craftsmen and experienced salespeople who will select the necessary part for you.
