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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 frequently 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.
Valves
During operation, pressure builds up in the water heater, which can lead to failure of the tool. To avoid this, a safety valve is installed, through the holes of which, with too much pressure, water will flow into the sewer through a silicone tube. You can do without it, then the water will collect under the water heater.
The water from the water heater is drained through the drain valve, which is connected after the safety one.
You can also install two 1/2 "or 3/4" copper tees for household appliances that require water, such as a washing machine or dishwasher. These tees cut into the hot and cold water supply system. Taps are screwed onto them so that it is possible to shut off the inlet and outlet of water from the water heater when it is not in use.
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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.
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.
Heating element and heat exchanger
The heating element is a spiral made of carbon or stainless steel, brass or copper. Used to heat water. Its service life depends on the resistance of the shell to corrosion and on compliance with the permissible temperature regime.
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And in indirect heating water heaters there is such a structural element as a heat exchanger. This is a device with which heat is transferred from a hot coolant to cold water. If it is out of order, then you can replace it.
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.
Wear criteria
If it is heavily soiled, the boiler body may start to shock or will not turn on.
There are several easily identifiable indicators that it is time to completely clean the unit and then change the magnesium anode:
- when the household device is turned on, after a while, the protection is triggered, which is explained by the presence of a thick layer of scale on its heating element;
- the previously observed water heating is completely absent when the boiler is operating normally;
- The equipment case begins to periodically "beat" with current, which is a sign of a violation of the quality of insulation due to the destruction of individual parts.
One of these manifestations is a reason to immediately stop operating the boiler and start examining it.Only a thorough study of the state of the electric water heater and the anode allows us to make a final conclusion about the need to replace them.
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.
The procedure itself
The ritual of replacing the heating element in the Thermex water heater is far from being able to withstand every householder, however, if you are a happy owner of this device, we will ease your lot with step-by-step instructions on how to replace it with your own hands
- We drain the water from the boiler. why first unscrew the nut from the hot water pipe, then unscrew the cold water;
Boiler Termeks inverted
Please note that the holes in the plastic are not centered. Do you think this is by chance? Not! Not by chance! Made in Russia!
Do not mix up the wires!
You may need to pry it off with a screwdriver. Often sticks to
The heating element can also get used to it and there is a need to pry it off with a screwdriver
Unscrew the electronics completely (4 screws);
Pour water into the boiler and drain, repeat until clean water flows out;
Scale can be several kilograms! Cleaning is a must!
The heating element must be equipped with a NEW gasket
Do not forget to put washers and grovers under the nuts
Be sure to insert the magnesium anode! It significantly increases the service life of the heating element and the entire boiler.
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.
Beginning of work
In order for the Ariston water heater to start working, it is necessary:
- Make sure the heater flange is well centered. If the flange is slightly shifted to the side, then by means of a nut, it must be loosened or tightened.
- Fill the water heater with cold water and open the hot water tap to allow the air to escape. Then again this tap must be closed.
- Inspect the case and make sure the device is not leaking.
When the heating mode is turned on, the light should turn on.During operation, the cold water hose may warm up. The temperature is regulated in some models with a special knob connected to the thermostat or with a screwdriver by turning the thermostat screw.
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
How to change?
The magnesium anode is a consumable part and must be replaced periodically. This process will not take a lot of time and effort. Anyone can replace the anode with their own hands. You can buy it at any service center or specialized store. Replacing the anode involves several stages.
- Disconnect the water heater from the network and drain the water. To make it faster, you can do this through a check valve. However, it is worth putting on a hose so that you can control the flow of water, otherwise everything around you will splatter.
- It is necessary to remove the cover from the bottom of the heater. At the end of this process, the thermal sensor and flange will open to view; they also need to be removed.
- You should lightly shake and pull out the heating element. This is not so easy to do, since some formations have already been deposited on it. Therefore, you need to make some effort so as not to damage it.
- The next stage is the dismantling of the old magnesium anode located next to the heating element. Very often, only an empty pin can be found at the site of the whole anode. These are signs of destruction of the magnesium layer. But you still need to remove it from the nest.
- At the same time, it is necessary to clean the heating element from scale and only after that a new anode can be installed. It is better to clean the heating element in working order, while the plaque has not hardened so much. It can be removed with a regular screwdriver. If, nevertheless, it hardened, then it must be dissolved in citric acid. The proportions should be as follows: for one liter of water, fifty grams of acid. The heating element must be kept in this solution for two days.
- After that, the boiler is carefully assembled to its initial state.
As you can see from the above, changing the anode is not so difficult. You just need to remember to look for bacteria and clean the surface of the tank inside the water heater. And also the anode should be changed regularly. All this will help to increase the service life of the 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 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 frequently, 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. 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 is filled with water and checked if there are any leaks. ...
Features of replacing the heating element in Termex
As already mentioned, the company has been operating since 1995 and produces only water heaters of "different" modifications. Why in quotes? Yes, because the difference between the models is minimal and this directly relates to the topic of the article.
The fact is that all Termex storage water heaters, both white and shiny and with remote control and with a display, have one feature, the company's chip - the flanges for attaching the heating element to the body. The diameter of the hole into which the heating element is inserted is 60 mm. Neither a tool nor a hand will get through such a hole.
For those who are not in the know, we explain that every time the heating element is replaced in any water heater (if we are not talking about a dry heating element), you need to clean it from the scale formed inside. And in the case of other brands, this can be done through the same heating element mounting flange. This is how, for example, cleaning the boiler looks like when replacing the Ariston heating element (the sight is not very pleasant, but better than with Termeks, believe me)
Boiler Termeks you will definitely have to:
- Shoot from the wall
- Fill with water
- Turn over in anticipation that all the "slurry" from the scale will come out
- Repeat steps 2 to 3 as long as you have the strength or until clear water flows.
No way to manually remove limescale not!
Another surprise from customer reviews is that the bolts on the flanges stick tightly to the nuts and there is no way to unscrew them. They are cut with a grinder. Do you have a Bulgarian at home? Didn't come with a boiler?
