Why do you have to clean the household electric water heater regularly?

Why should electric water heaters be cleaned regularly?

Water heater heating rods form severe scale

When the household electric water heater is used, the calcium and magnesium ions in the water will be decomposed by heat, and will form a scale on the surface of the metal heating rod with high temperature, that is, calcium carbonate and magnesium hydroxide. In addition, when the tap water is not completely purified, it may be Contains colloids, particulate matter, rust, sediment, etc. They can also be combined with small scale particles to form a thick layer of scale on the heating rod. The longer the time, the thicker the scale.

Water heater magnesium rod and heating rod position

Replace the magnesium rod

In order to effectively avoid scale, many water heaters are now equipped with magnesium rods. The working principle of magnesium rods is the principle of cathodic protection. The so-called cathodic protection is to add a large amount of electrons to the metal to be protected (water heater heating rod) to protect the metal ( The water heater heating rod body is in an electronic excess state to make the surface of the metal (water heater heating rod) reach the same negative potential, and the metal (water heater heating rod) atom becomes into the solution because it is not easy to lose electrons. Generally speaking, the metal activity of the magnesium rod is Higher than iron, it will preferentially react with ions in the water to protect the inner tank and the heating tube. However, the magnesium rod only works when it is energized, it will be consumed continuously during use, and needs to be replaced after consumption. The use time is affected by several aspects: The temperature of using hot water, the higher the water temperature, the more severe the corrosion of the inner tank, the faster the magnesium rod consumption, it is recommended that the hot water temperature of the water heater be set below 60 degrees; The amount of water used, the same hot water temperature, the higher the amount of hot water, the faster the consumption of magnesium rods; the higher the calcium content of the water, the greater the hardness, the more the magnesium rods are consumed. The larger the magnesium rod is, the longer it is used. Generally, the service life of the magnesium rod is two years. Therefore, if the electric water heater is not cleaned for more than two years, and the water quality is not good, a lot of scale will be generated, and the scale will deposit. To the bottom of the water heater liner. Once a large amount of scale is attached to the heating rod, the heating efficiency will be greatly affected. To reach the set temperature, the water heater takes more time. At the same time, the scale is too thick and the liner will overheat and deform. The drum kit is even broken. If it is not cleaned for a long time, the water pipe will be fouled, which may completely block the pipeline and damage the water circulation. In severe cases, it will cause a pipe burst accident.

Electric water heater internal structure

Some people may question, the water heater has been used for more than two years. Why didn't you see the sewage coming out? Because the hot water outlet of the electric water heater is at the top of the liner, the inlet is at the bottom of the liner, and the scale is mainly attached to the surface of the heating rod and deposited. At the bottom of the tank, cold water continuously enters the water tank liner, the hot water is squeezed to the top, and the scale is deposited at the bottom of the tank, so the water coming out is the clean water at the top, and the turbid sewage will not flow out from the shower nozzle. However, as the scale accumulates at the bottom, it will hinder the water inlet, the water will be slower, and the water will be slower. If you find that the water is not as big as the bath at home, it is necessary to clean the water heater as soon as possible.

Electric water heater cleaning steps

Water heater single channel water lower layout

Electric water heater scale accumulation diagram

By understanding the above knowledge, especially the internal water inlet and outlet location, we can simply do this, without removing the water heater, remove the dirt deposited on the bottom of the electric water heater. We know, the water heater The cold water inlet, the pressure relief valve (safety valve), the sewage outlet are all underneath, and the dirt is also below. Therefore, when cleaning the water heater, we can let the dirt be discharged at the lower water outlet. Here are some methods:

Water heater triangle valve

Step 1: Unplug the power outlet and turn off the lower triangular valve of the water heater, that is, the cold water inlet and the hot water outlet valve;

Use the pressure discharge port to discharge

Method 1 (no need to disassemble); use natural drainage of the pressure relief port, discharge: keep the cold water inlet closed, open the hot water outlet valve, and then open the pressure relief valve drain switch (the drain switch rotates 90 degrees counterclockwise) to make the inside of the water heater The water naturally flows out, and some of the sediment will be taken out when the water is discharged. The 60L water heater will drain for about 30 minutes. If the water that is finally brought out is particularly dirty, you can repeat the process again, that is, close the pressure relief port and open the cold water inlet. The hot water outlet is kept open, and the water inlet is almost full. Close the water inlet again and open the pressure relief drain. After the entire cleaning process is completed, restore the pressure relief valve drain switch position, open all valves, and fill the water. After powering up.

Open the water heater drain

Method 2 (open the sewage outlet): Open the hot water outlet valve, keep the cold water inlet valve closed, and unscrew the nut of the sewage outlet. At this time, the water inside the water heater will carry most of the floc in the inner tank. The dirt is discharged together. When the basic discharge is completed, the process can be cycled again, that is, the sewage outlet is closed, the cold water inlet switch is opened, and when the water is injected, the water inlet can be closed, and the sewage outlet can be drained until there is no more sewage. When it is excluded, the dirt at the bottom is basically removed. It is said that in this way, the metal hose of the cold water pipe can be connected to the hot water outlet of the water heater, and then the inlet angle valve is opened. Cold water is flushed into the tank from the hot water inlet. The premise of this method is that you need to know if your home's water heater has a check valve, that is, if there is something to prevent water from being poured. After clearing this point, use The cold water pipe is connected to the hot water inlet, and a large amount of tap water is used to flush the inner tank through the hot water inlet, which can quickly discharge the water in the dirt, save time, and repeatedly wash the water until the water inside is clean. only.

Through the above method, you can clean it once every six months. This can not only prevent the bath water from being contaminated by the dirt deposited by the liner, but also enhance the use effect of the water heater and prolong the service life of the water heater.