The boiler is constantly in contact with water. And the main danger to the water heater is rust and corrosion. If in the old days people dipped a silver coin into the water so that the water retained its properties longer and did not deteriorate, then for modern boilers a special anode is used.
What is the magnesium anode for a water heater for? The photo gives a clear answer. This special rod is installed inside the device body. It prevents rust and extends the life of the water heater.
Unlike silver, which killed bacteria in water, a special magnesium anode for a water heater takes salt out of the water, thereby preventing corrosion in the device’s internal tank. The fight against rust is always relevant: despite the fact that the tanks of water heaters are made of stainless steel, corrosion continues to do its job.
A seemingly eternal stainless steel is influenced by at least two factors that completely dispel the myth of its extraordinary durability.
Electric water heater or boiler
Stainless food steel, from which the tanks of most water heaters are made, can only withstand short-term hard and salt water. If steel of the proper quality were used in the manufacture of these devices, then the price of water heaters would increase many times, making them inaccessible to many buyers.
The tank of any boiler in which water is heated is not solid, it is most often welded from two parts. After welding, the crystal lattice of the molecules of steel changes due to high temperatures, and it is in the places of the welds that such a valuable property of this material as the ability to withstand rust is lost.
Despite the fact that the inside of the tank is covered with a paint and varnish coating, it also collapses 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 life of the water heater is affected not only by poor quality water, but also by the use of metal producers with different potentials.
The principle of operation of the magnesium anode
If you do not install the anode for a water heater, then such a device will turn into a galvanic couple, described by scientists in the XVIII century. Instead of the anode, the boiler body will begin to work and, accordingly, it will begin to collapse, since the other elements used in it have a greater electrochemical potential. Installing an anode with a lower potential in the casing protects the casing from destruction.
When buying a boiler, the anode is usually not paid attention, moreover, it is hidden under the body of the device. It is not a very smooth grayish rod. Over time, during operation, the anode will begin to look like it is corrupted, and the walls of the casing will remain intact. This is the only task of the magnesium anode installed in the water heater.
Magnesium anode
Magnesium is used to coat anodes for water heaters because of its low price and low electrochemical potential. Salts, which are released from the water due to the anode, do not actually disappear anywhere, but settle on its surface.
Thus, the anode is just a pin made of metal, on which a layer of magnesium alloy from 10 to 15 millimeters is applied.
Symptoms
When using a water heater, it is useful to periodically listen to the sounds it makes. If there was a hiss during the heating of the water - most likely, a plaque appeared on the heating elements, and it is desirable to clean the device from scale and mineral salts.
Even with the high purity of the water used, salts are always present in it, only in varying degrees of concentration. Even the anode with excessive salt content in the water will not be able to completely cope with them. Therefore, when using water with a high salt content, it is recommended to use various filters and water softeners.
Despite the apparent simplicity of the water heater and the presence of a magnesium anode in its body, only in practice can we understand when it is time to look inside the boiler and clean it. If the destruction of the magnesium anode for the water heater is detected, for which a visual inspection is necessary, then according to the state of the pin, we can assume how much time he has to work effectively. It is better to replace it with a new one right away, without waiting until it is completely destroyed, and the boiler will remain unprotected.
For self-replacement of the anode, special tools are not required, and anyone can do such work. The only thing you should not neglect is the observance of safety measures.
As a rule, cleaning the water heater is required after a year of operation, however, for preventive purposes, you can perform it earlier.
By removing plaque from the heating elements or from the bottom of the tank, as well as checking and changing, if necessary, the anode for the water heater, it is possible to significantly extend the life of the device.