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About the anode in the water heater, its properties and principle of operation, you need to know everything, because it affects the service life. If you do not change it, it has a bad effect on the duration of the boiler. What it is, what it is for and how to replace it, read below in our article.
The purpose of the magnesium anode
It protects the tank from corrosion and takes over all oxidation processes. Let’s take a closer look at how storage water heaters work.
Tanks of boilers “Termex” or “Ariston” are made of stainless steel or covered with a protective layer of enamel. According to the statement, stainless steel does not give in to corrosion. But the following points should be taken into account:
- The body is made of food grade stainless steel. The material is not able to resist oxidation for more than six months. If the manufacturer used high quality steel for manufacturing, the cost of technology would be too high.
- The tank is not created in one piece. Basically, it consists of two parts that are connected by seams. Under the influence of high temperatures, the seams can be deformed, which leads to a loss of the properties of the stainless material.
What else do you need to know? Manufacturers try to prevent a reaction by coating the inner walls with protective agents. Over time, they also lose their effectiveness. When heated, water expands the metal, so the alloy is stretched, losing its properties.
After the formation of microcracks, oxygen oxidizes the metal, which leads to irreversible corrosion.
The metal case and the heating element create a galvanic couple. The case in this case acts as an anode. So that it does not deteriorate when exposed to water, manufacturers installed an alloy next to the heating element, which includes magnesium. He takes on the role of the anode – as a result, all the oxygen goes to its oxidation, and the tank remains intact.
Over time, the alloy is destroyed, its particles settle to the bottom of the case, so a new one must be installed periodically.
Almost all Polaris, Gorenie, Electrolux brands include magnesium anodes in their models. How do they look? It is an alloy on a stick with a flat surface. During operation, corrosion begins to corrode their surface.
Why choose magnesium
Is it really impossible to make an element from other materials? In fact, the cost of magnesium is low, which allows not to increase the cost of the finished product. It also has a weak electrochemical potential. Magnesium attracts salt from the water to itself, preventing it from settling on other parts.
What is the life of the anode and how often should it be changed? Experts recommend replacing every year.
Signs when it’s time to change a part:
- Noise is heard during operation.
- The water acquired an unpleasant odor, became cloudy.
- Prolonged heating.
- Frequent switching on and off of the boiler.
This also indicates that the heating element is completely covered with scale and needs cleaning.
You can perform it at the same time as replacing the anode.
How to replace the magnesium anode with your own hands
Consider how to unscrew the details yourself:
- Disconnect the equipment from the network. Turn off the machine if there are contacts leading to it.
- Drain the water. The fastest way to do this is through the check valve. Shut off the water at the main valve, unscrew the water hoses and turn the check valve.
- In Gorenje models, the magnesium part is located on top. In order not to remove the boiler from the wall, simply pry off the top cover. If this is not possible due to proximity to the ceiling, the case will have to be removed.
- In other models, you need to remove the bottom cover. To do this, unscrew the fixing bolts and remove the latches.
- If the heating element is fixed on the flange, unscrew the nuts and screws, pull out the flange. Sometimes the heater must first be pushed in and then removed from the tank.
- The anode is unscrewed from the stand next to the heater.
How to select a new element? If you do not know how to replace the old one, take it to the store. The part must be selected according to the diameter of the thread. For example, in the Thermex Flat Plus model, the number is M4.
Install in reverse order.
How to extend the life of your water heater
Monitor the operation of the boiler in order to detect and fix the problem in time:
- Do you hear a hissing sound when drawing water? This means that the heater is covered with scale. Need to clean it up.
- It is advisable to install water filters. They reduce the concentration of impurities that subsequently settle on the parts.
- Occasionally look under the case cover to check the condition of the anode. If it is half worn out, it will need to be replaced soon.
- If you removed the old one, but did not have time to install the new element, do not start the technique. Buying a new element will cost less than buying a new boiler.
- Frequent use leads to rapid scale formation. Therefore, it is recommended to clean the tank once a year.
Decided to replace yourself? Be sure to unplug the heater and drain the water. Then start repairing. A video about replacing this part in the boiler will help you: