Modern water heaters are made of stainless steel. At the same time, such devices require additional protection against corrosion processes. Magnesium anode is an integral part of many boilers. They significantly extend the service life of electrical equipment. Let's look at the operating principle of this part. We will also determine why a magnesium anode is needed in a water heater, how to properly install and operate it.
Condition of the heater after long-term operation Source tproekt.com
The need to protect the water storage tank
Many people wonder why an anode is needed in a water heater, since its body is made of high-quality materials. The raw material for the production of the tank is usually food steel. It is corrosion resistant and durable. But with constant contact with water with impurities, the material gradually breaks down. Negative processes begin to appear after 12-18 months.
This problem can be solved by using industrial types of steel that are not susceptible to corrosion. But such materials cost quite a lot. This will make the boiler an expensive device that is not accessible to the general public.
It is clear why a magnesium anode is needed in a water heater, given the presence of seams between the elements of the electrical appliance. Under the influence of constant heating, the structure of materials changes over time. As a result, microcracks form, which triggers the corrosion process.
Design of a classic water heater Source 1popechi.ru
The special coating does not protect the device from destruction so well. It is not durable, given the periodic changes in temperature inside the tank. Hot water causes the metal to expand, which contracts when cooled. After such changes, the protective coating is deformed and gradually cracks.
The question of why an anode is needed in a boiler does not arise, given that rather hard water passes through the device. Its chemical composition does not always meet established standards. This negatively affects the condition and service life of the housing and unit parts. It is the magnesium element that helps cope with the “imperfect” composition of water and extend the life of the electrical appliance.
Tank corrosion Source pechiexpert.ru
See also: Catalog of companies that specialize in the design and installation of sewerage and water supply
Reviews
Alla, Kolomna:
“We bought an Ariston boiler without a magnesium anode. They didn’t know why it was needed and didn’t overpay for it in the store. Then they regretted it. Friends told us that in six months our storage tank will no longer be operational. Therefore, we urgently ran to buy and install. The most interesting thing is that after the replacement the taste of the water changed. She became similar to the one that can be found in springs. Very good. I recommend to everyone".
Leonid, Astrakhan:
“Immediately after purchasing the Electrolux water heater, I regretted that I did not take a safety rod with magnesium. Literally six months later, my boiler simply turned black from a coating of salt and other deposits. I called the experts, they said that it can be treated, but the enamel surface can be damaged. They advised me to get rid of such a boiler, which I did. Then I corrected myself and took it with the anode. Heaven and earth. Every six months I check and clean the boiler, and it doesn’t have the same effect as before. True, the rod has to be changed often, apparently the water in our house is so bad.”
Features of operation and purpose of the element
To understand what the anode is for in a water heater, you need to consider that the stainless steel from which the walls of the tank are made is an iron compound. After heating the water, the aggressive components in its composition begin to interact with metal elements. As a result, oxides are formed and the electrical appliance is destroyed.
It is clear why a magnesium anode is needed for a water heater, since the element prevents the formation of a galvanic couple inside the unit. This metal is divalent, in contrast to the ferric iron from which the body is formed. Therefore, magnesium has increased activity. The material reacts with salts in water.
Destructive processes are directed to the anode in the water heater, and not to the walls of the tank. Carbonic acid compounds are actively formed. As a result of this chemical reaction, loose scale appears. It is easy to remove during the next repair or cleaning of the unit. The anode in the water heater plays the role of protective protection.
Comparison of a new one and an anode that has been used for a year Source khersonline.net
The purpose of an anode in a water heater should also be considered from the point of view of energy efficiency. In its absence, active scale formation occurs. As a result, the user is faced with an increase in the time required to achieve the specified water temperature. Electricity consumption also increases and the efficiency of the device decreases significantly.
When to clean your water heater
The electric water heater needs cleaning when:
- the device turns on/off frequently;
- the water heating time has increased;
- There is a barely audible hissing sound as the water heats up.
If cleaning is not carried out frequently, then more electricity will be spent on heating the water, the heating element will become overgrown with scale, which will subsequently lead to difficulties when trying to remove this part from the water heater without the risk of damage.
The regularity of cleaning the water heater depends on the intensity of its operation, water hardness, and operating temperatures. If the water is hard, annual cleaning is recommended. In case of soft water and irregular use of the device, cleaning is carried out every 2 years.
Design and varieties
To understand what a magnesium anode is in a water heater, it is necessary to consider its design. This element is a thin steel rod. A thin layer of magnesium alloy is applied to it. The anode for the boiler also contains other chemical compounds - titanium, zinc. The appearance of the part depends on the technical characteristics of the water heater itself.
A wide range of water heaters implies the presence of different types of anodes Source mobile-review.com
Types of magnesium anodes
The magnesium anode is made in the form of a metal rod onto which a layer of magnesium up to 2 mm thick is sprayed. Its length varies from 10 cm to one meter and depends on the size of the boiler. In domestic water heaters with a volume of up to 80 liters, it is installed next to the heating element on a small round platform using a threaded connection.
In electrical appliances that are used in hotels, hostels, production workshops and have a volume of more than two hundred liters, it is installed on top of an element that is screwed into the body.
Depending on the number of rods, single and multi-section protective devices are produced.
- The base of the rod is made of high-carbon steel or in the form of a plastic fine mesh.
- The plastic rod has small holes into which magnesium cations freely penetrate and are distributed in the aquatic environment.
- Magnesium powder is poured inside the empty cavity of a plastic tube.
- It is easy to add it inside as it is used up, plastic is a flexible material and replacement is faster and easier.
Removing the protective element
Replacing the magnesium anode in an Ariston water heater or in a device from another manufacturer is carried out according to the same scheme:
- Disconnect the device from the power supply and turn off the cold water supply using the tap.
- Open the faucet to release excess pressure from the water heater.
- Turn off the hot water tap.
- Attach a flexible hose to the water drain pipe. Take him to the sink. After unscrewing the hot water hose, the contents of the water heater will flow into the sink.
- Remove the cold water hose.
- Remove the lower part of the electrical appliance.
Removing the bottom cover of the water heater Source msd.com.ua
Cumulative or flow-through
In fact, the choice is not that great. There are two main types of water heaters:
instantaneous water heater
storage boiler
In a flow type, the water heats up very quickly; it only needs to pass through the heating element. It seems that what else is needed?
However, such heating implies a sharp decrease in the maximum possible pressure.
If you want to get a more powerful flow, in this case you will have to use a more powerful heating element from 8 kW to 30 kW!
In storage water heaters, there is practically no change in pressure. What's in is what's out.
Thanks to this, this type can simultaneously provide several points in the house with hot water supply. But this is when using a water heater of the appropriate volume (100-150-200l).
And their choice of volume is quite extensive - from 5 to 300 liters.
Useful tips
Considering why a magnesium anode is used in a water heater, it is appropriate to use the following recommendations to increase the efficiency of the equipment:
- There should be no suspicious sounds when operating the equipment. If there is a hissing sound, you should check the device, as this is a sign of scale.
- It is advisable to carry out routine inspection of water heating equipment twice a year. If damage is detected on the surface of the rod, it is recommended to replace it.
- It is advisable to install a filter on the pipeline supplying water to the boiler. This will extend the service life of the equipment and allow you to increase the time between scheduled repairs.
- If heating occurs very slowly or the device periodically turns off and does not heat the water, it is necessary to check the condition of the magnesium rod and the heating element itself.
How to determine whether a part needs to be replaced
During operation of the water heater, you can visually and audibly determine that it is time to replace the installed magnesium anode.
It is necessary to ensure timely replacement. Photo source: domikelectrica.ru
This can be done using the following indicators:
- The water heater began to take longer to warm up.
- The device often turns off and turns on again.
- The heated water coming out of the mixer has become cloudy and has an unpleasant odor.
- During the heating process of the water heater, noise is clearly audible.
If at least one of the above indicators exists, it is necessary to replace the magnesium anode. Moreover, most of the listed signs indicate that the heating element is covered with scale and also requires cleaning. This can be done together with changing the anode.
Briefly about the main thing
To understand what an anode is in a water heater, you need to understand the chemical processes that take place inside the electrical device. The water and salts contained in its composition actively interact with metal parts inside the unit. Therefore, a magnesium rod is used to prevent corrosion.
When considering why an anode is used in a water heater, you need to take into account that the metal of which it is composed is characterized by increased activity. Magnesium is the first to enter into a chemical reaction with other components, preventing its development on the body of the unit. Using an anode for a water heater, which requires only periodic replacement of the element, you can extend the life of the electrical appliance for decades.
Why magnesium
This question worries many people. The secret lies in the electrochemical potential. This element has a very low value. At the same time, the price of this metal makes it possible to use it in industrial quantities, without increasing the price of the 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 install them on units of various modifications, for example, Ariston, Electrolux and other popular models. Similarly, they are suitable for Russian-assembled Termex electric water heaters and for indirect heating boilers.
