Anode selection rules for water heaters

When buying a water heater, not everyone knows what elements it is made of. So, in each heater is a sacrificial anode. But why it is needed and how it looks is still not known to everyone. And it is necessary to know at least in order to be able to choose it correctly.

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. Attach it very close to the heating element. This is done so that in the event of a repair or inspection, the anode and the electrode can be pulled out together. However, there are also such models where they are installed separately.

The anode performs two functions in the heater at once. The first purpose, which is considered to be the main one, is to protect the device and some elements from corrosion. The second appointment is a kind of bonus: it makes 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 with calcium salts and carbonates. The magnesium anode cannot fully protect it from this, but still makes this problem not so terrible. When the anode and carbonates interact, as a result of the substitution on the heater itself magnesium salts are deposited. They have a very soft structure. Therefore, they can easily be removed mechanically, even without damaging the heating elements.

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

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

However, this is still not enough to protect against rust. This is where the anode comes to the rescue. It would seem, why the anode in the heater, if it has excellent protection without it. But after all metal in any case will start to rust, especially in places of welding. Paint over time can also become covered with small cracks, and then the water through them will fall on a metal surface. In this case, the 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, corrosion may appear on it, but this is not terrible, since the tank of the water heater will remain intact.

It is imperative to install a sacrificial anode for a boiler covered with ordinary metal. After all, such a material without additional protection has a short service life. Even if the tanks inside are covered with a layer of stainless steel, it still does not save the water heater.Therefore, you need to buy additional parts, so you do not spend money on repairs. Any heater manufacturer makes recommendations on how to choose the size of the anode. In principle, the anodes can be divided into two types - it is magnesium and titanium.

The magnesium anode, as mentioned above, is made of a conventional rod or, in other words, a rod, inside of which there is a threaded steel stud. The pins themselves can be of different diameters and different lengths. It is worth paying attention to this when buying a new anode, because if its size is several times larger, it will not fit into the opening of the tank. However, there are some designs where you can install even two anodes. In the floor gas or electric structures with a large volume, they change only from above.

The anode rod has a very large size, its length is approximately one meter. Therefore, its replacement will be a problem in rooms with low ceilings. Since the water heater itself has a height of up to two meters, plus a meter rod must also be inserted into it. For such purposes they began to produce multi-section protective magnesium anodes.

They are made of plastic tube with micropores. Magnesium granules fall asleep inside this tube. The advantage of this new product is that there is no precipitation inside. In addition, magnesium can be added to the tube as it is produced. Magnesium powder sold separately.

High-quality aluminum water heater does not need such additions. But at the same time the high price makes it inaccessible for ordinary citizens. But the usual boiler, supplemented with a magnesium anode, will be affordable for almost everyone. At the same time, it is not worse in functionality. The principle of its operation is that the active magnesium atoms leave the anode, and themselves produce oxide. Iron atoms remain completely intact.

But the anode with a titanium coating works a little differently. It is used as a measuring and supply electrode. In this case, the current is supplied by a voltage source located outside, and it is also regulated by external electrical control. After some time, the current ceases to flow and then the titanium anode analyzes the state of the internal parts of the structure.He reveals what kind of violation occurred during this period and then with great precision regulates the possible feed force to repair the damage.

The anode with a titanium coating is not subject to destruction, and therefore does not need to be replaced. It works throughout the life of the structure. Heaters for 50 liters of water, supplemented by such an anode, are in the greatest demand. They are not only compact, but also convenient to use. By the way, to make sure that the anode is really titanium, it is possible through the use of a magnet. This material has a weak magnetic field, so it is not magnetised at all.

The magnesium anode is a consumable part, so it must be replaced periodically. This process does not take away a lot of time and effort. Anyone can replace the anode with their own hands. You can buy it in any service center or specialty store. Replacing the anode involves several steps.

• Disconnect the water heater from the mains and drain it. To make it faster, you can do this through a check valve. However, it is necessary to put on a hose so that you can control the flow of water, otherwise everything will splash around.
• It is necessary to remove the cover from the bottom of the heater. At the end of this process, a thermal sensor and a flange will open up; they also need to be removed.
• It should be gently rocked and pulled the heater. This is not so and easy to do, since some formations have already been deposited on it. Therefore, you need to make some effort not to damage it.
• The next stage is the dismantling of the old magnesium anode, located next to the heater. Very often, on the site of the whole anode, only an empty pin can be detected. These are signs of the destruction of the magnesium layer. But still it needs to be removed 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 condition, while the deposit has not hardened so much. It can be removed with a conventional screwdriver. If, however, it has hardened, then it must be dissolved in citric acid. The proportions should be such as: for one liter of water, fifty grams of acid. Heater need to hold in this solution for two days.
• After that, the boiler is carefully collected in the initial state.

As can be seen from the above, changing the anode is not so difficult.Just do not forget to look, if there are bacteria, and clean the surface of the tank inside the water heater. And also change the anode should be regularly. All this will help to increase the life of the water heater.

It is necessary to adhere to such advice from experts as:

• to extend the life of the heater, you need to monitor its operation. If a hissing sound is heard during water intake, it means that scum has appeared on the heater, so an urgent need to clean the boiler;
• it is necessary to put water filters, which in many respects reduce the concentration of various impurities that settle on the parts;
• need to look at the state 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 is not yet installed, it is not necessary to 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, so cleaning the tank should be done once a year, and 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 only for a while. Protection will last just a year and a half. Therefore, it is better to buy a water heater with a magnesium anode, which will cope with all the problems.

However, it does not go further. After all, the cost of such products will be exorbitant. People simply can not buy them, so manufacturers continue to create water heaters with anodes. Magnesium is necessary in this case, because it not only has the ability to attract salt to itself and prevent its sedimentation on important elements of the structure, but also has a small electrochemical potential.

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

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 an anode with a titanium coating, and forget about its existence.

How to replace the anode, see the following video.