Alexander Shub, expert reviewer of household appliances and electronic portable gadgets

The principle of operation of an electric water heater

Storage water heater with a flat tank from the French company Atlantic

The principle of operation of an instantaneous water heater

Instantaneous water heater Zanussi

Instantaneous water heater Thermex 15 kW. With this, you can take a shower. If you are not intimidated by the upcoming electricity bill!

The principle of operation of the indirect heating boiler

Indirect heating boiler

The principle of operation of the combined boiler differs from the indirect one in that it can heat the water in the tank not only with the heated liquid from the heating boiler, but also through its own heating element

Ballu water heater

Ariston horizontally installed water heater

Example of a diffuser (inlet diffuser) of water

Photos from the French Atlantic plant

Photos from the Ukrainian factory Atlantic near Odessa

Steatite dry heating element for Atlantic boilers

Ariston has a full cycle production facility in the Leningrad Region. Judging by the materials available on the Web, only boilers with a cylindrical body are produced here

Several photos from Rusklimat’s participation in the Aquatherm Moscow 2020 exhibition. I would like to see the photos in more detail, but … On the official website of the holding, only frames in small resolution 650×488 pixels are published

Screenshot from home-comfort.ru website. In fact, from the Swedish Electrolux there is only a brand

… When the stainless steel turned out to be very “rusty”

These rods can be used as filler material. That is, they are used as a connecting link at the junction of the boiler tank walls.

Electrolux EWH 30 Major LZR H – a water heater with a stainless steel tank at a price of 8 rubles

Boiler with enamel coating inside the tank

The advantages of enamel include:

• Relatively low cost of application – despite the fact that in terms of its protective properties, enamel with a high-quality composition and application is not inferior to high-quality stainless steel.
• High wear resistance, the ability to use even the most “hard” water.
• Formation of a non-toxic, biologically neutral surface.
• Preventing the growth of bacteria in the tank.

In addition to the composition of the enamel, the application method plays an important role. The best way is electrostatic powder coating with further firing at a temperature of 850 ° C. This is the most expensive, but also the most reliable method of obtaining a resistant, non-corrosive coating. Here, for sure, the tank will in no way be inferior in durability to that of an expensive stainless steel. If the manufacturer is confident in the durability of the container, then the corresponding guarantee is given – 7 or even 8 years. Against more “standard” 5 years. Well, if the tank warranty is only 2-3 years, this is an unambiguous reason to bypass a specific boiler, and indeed the products of such a manufacturer, by the side.

Ukrainian plant of the French company Atlantic, a site with a furnace for firing water heaters

Thrifty manufacturers are not averse to using the outdated, but cheap way of applying enamel – bulk (liquid). In this case, a whole heap of probable problems is recruited, from poor adhesion to the tank and cracking to the presence of toxic components. Unfortunately, it is impossible to determine the enamel application method purely by characteristics. Therefore, as I noted above, pay attention to the warranty period. Or look for videos from the production of a particular company. For example, at 02:40 it is shown how at the Ukrainian plant of the French company Atlantic, enamel is applied precisely by the powder method.

Which water heater is the best for energy efficiency?

Electric boilers, pardon the tautology, are powered by electricity. Therefore, an enterprising consumer probably wants to get a model that, in comparison with competitors, with the same power of heating elements and a liter of tank, will consume as little electricity as possible. The question is – how to objectively understand which water heater is economical and which is not very?

The answer is both simple and complex. The easiest way is with water heaters, which are also sold in the EU countries. Since 2015, such devices have been undergoing mandatory testing for the assignment of an energy efficiency classification ErP (Energy related Products).

To be precise, we are talking about complex information. Boilers in the EU must be accompanied by this label, which indicates the energy efficiency class, annual calculated energy consumption and noise level during operation. I will clarify that energy efficiency mainly reflects the ability of a boiler to minimize the cost of maintaining a given water temperature. Therefore, the water heater should have everything “ok”, first of all, with heating elements and thermal insulation.

Atlantic Boiler Energy Label

Among domestic boilers, the highest energy efficiency class, “B”, is mainly found in all Atlantic models, and is found in selected Ariston boilers. It is much more difficult with Electrolux, Ballu, Zanussi and other brands of Russian owners from Rusklimat. Their products are not sold in the EU, and therefore have the right not to meet even the minimum requirements of the ErP directive.

Note that it is not so easy to find information on ErP. On the website of Russian representations, this information, as a rule, is not indicated. And for some reason you can’t even find them in the instructions. Therefore, mentally prepare yourself to thoroughly “shake” the consultant of the online store. Who will have to strain and find a sticker in the box with the model (as in the photo above) with the information the consumer needs. Or, the easier way is to find a store that offers the widest possible selection of water heaters. Then the consultants will certainly have boxes of products at their side and the ability to quickly remove the required label from the package.

If you are not afraid of the language barrier or the quirks of automatic translation of web pages, visit the “original” (read – European) sites of the same Ariston and Atlantic. There, on the page of each model, an ErP rating is always given. Alas, for the same Electrolux, information cannot be found even on the website, because in fact it is a Russian brand with production and development in China. And without sales in the European Union.

Fragment of a page on the English-language site Ariston. Energy efficiency class is indicated for each model. Also, under the tap icon, you can see on which “profile” the amount of hot water was measured. Roughly speaking, it’s like a clothing size, from S to L. The higher, the more hot water will be, although the energy efficiency classes may overlap

This information is not indicated on the Russian-language site.

Types of heating elements

Which water heater is better, if you start from the type of heating element? Unfortunately, in about 99% of cases, the authors of articles on the topic “how to choose a water heater”, due to their own low competence, “disarm” the consumer. In the sense – they provide completely incorrect information about modern species, in particular, dry heating elements. As a result, they interfere in one heap and reward completely different electric heaters with the same advantages and disadvantages. Well, I hasten to correct this state of affairs.

Heating elements for boilers are divided into three types.

Wet (submersible) heating elementsusually copper. By design, this is an ordinary electric boiler, where a heating nickel-chromium thread is contained in a hollow tube. Quartz sand acts as an insulator with high thermal conductivity. Water heaters with dry TEN appeared only in 2012, and before that wet “heaters” were, in principle, the only available option for the consumer.

Copper heating element for storage water heater

• Dry steatite heating elements… Patented development of the French company Atlantic. In other words, there is no concept of “dry steatite heating element” apart from this manufacturer. In any case, it is the “dry steatite heating element Atlantic” that is meant. It is based on heating elements from a subspecies of ceramics – steatite. This natural material has excellent thermal conductivity, high mechanical strength and durability, and can withstand temperatures over 1000 ° C. The bottom line is that the heating element does not have direct contact with water, as it is protected by a steel enameled flask. A predictable plus – the service life is on the verge of fantasy. Up to 20 years versus 2-3 years for an ordinary wet copper heating element.

Dry steatite heating element Atlantic for storage water heater

• Pseudo-dry heating elements… Of course, other manufacturers didn’t want to lag behind Atlantic. But to become completely dependent on one company and to pay royalties to the French for the right to use their technology, apparently, was not part of the plans of competitors. A rational understanding of the benefits of steatite heating elements outweighed corporate pride only for a couple of brands like a small Drazice with a single plant in the Czech Republic. In general, Atlantic’s competitors decided by any means to achieve the ability to call their heating elements “dry”. Even if it has almost no real advantages over conventional wet copper counterparts. What came of this, I will tell you very soon.

Black “pins” are pseudo-dry heating elements, which are inserted from below into enamelled steel tubes.

And now – in detail about each type of heating element.

Ordinary wet heating elements.

Plain wet copper heating element

Advantages:

• Lower price of the boiler in comparison with models with dry steatite heating elements. This is especially evident in the Atlantic assortment, where almost all models are presented in versions with both dry and wet heating elements. Depending on the displacement and other features, the price for steatite options is 10-30% higher. But not 100%, as the authors of some articles on the topic “how to choose a boiler” claim. Looking ahead, I note that this difference of 10-30% is subsequently covered by dry heating elements by about three times lower operating costs. So the miser pays twice – this saying most accurately reflects the main disadvantage of conventional wet heating elements – high maintenance costs.
• Cheaper “consumables”, in particular, heating elements – in comparison with steatite options. So, a wet heating element for 1 W from Atlantic costs 500 rubles, and a dry one – 1 rubles, almost 500% more expensive. But, again, a spoiler – you need to change the steatite electric heater every 2 years, while a wet copper one – on average, once every three years.

Disadvantages:

• The main disadvantage is that with a relatively small heat transfer area, an extremely high heat release per square centimeter of the heating element surface is obtained. As a result, the formation of scale, that is, solid deposits of salts, occurs with increased intensity. So much so that the magnesium anode is not able to fully loosen it. Over time, the heating element becomes covered with a dense hard crust of limescale. Due to this, heat transfer decreases and it takes more and more time, and therefore, electricity to heat water. If you miss the timely cleaning of the heating element or its replacement, the electric heater may simply burn out over time.
• Another drawback, which manifests itself mainly when untimely cleaning the boiler tank. The loosened scale accumulates in the form of flakes at the bottom of the tank. Over time, a rather high layer of several centimeters forms, which sticks around the base of the heating element. In the case of a wet electric heater, heat transfer occurs over the entire surface, including directly from the base. Therefore, only a dense ring of scale flakes at the bottom is enough to impair thermal conductivity or disable the heating element.

Bursting wet heating element

Dry steatite heating elements… Benefits:

• The key idea of ​​a dry heating element is to separate the protective shell of the heating element from the electric heater. Atlantic developers fundamentally solved this problem in the 90s. But an Atlantic water heater with a dry heating element appeared only in 2012. Free flowing quartz sand was replaced by the solid mineral steatite. Which made it possible to separate the protective flask into a separate element, not in contact with the heating element. Therefore, the electric heater was completely isolated from contact with the liquid in the tank. And I got the opportunity to work with equal success in water with any degree of hardness.

Dry steatite heating element in a protective flask in a boiler

• At the same time, the design genius of the French lies in the passing solution of another key issue. Namely – increased heat transfer per square centimeter of surface in conventional wet heating elements and intensive formation of scale. Due to its device, a wet heating element cannot be made “plump”. But steatite is easy, which means that at the same time we will get a more voluminous flask. As a result, the total heat release from wet and dry heating elements is the same. But per square centimeter, the steatite variant is 3-4 times lower. Therefore, the intensity of scale formation is up to 4 times lower. The load on the magnesium anode is significantly reduced, which will need to be changed not annually, but once every two to three years.
• Steatite heats up quickly, but cools down for a long time – which predictably leads to less energy consumption compared to conventional wet copper heating elements. The benefit in favor of a boiler with a steatite heating element is about 10% in comparison with models with a wet heating element.
• A nichrome spiral in a dry heating element is laid so that the lower part of the flask and the electric heater remains practically cold. The main heating occurs about 5 centimeters above the “foundation”. Therefore, unlike wet heating elements, there are no conditions for fouling the bottom of the flask with a dense ring of scale with a subsequent deterioration in heat transfer up to the breakdown of the electric heater.

The blue zone remains relatively cold, the main heating of the heating element is higher. Therefore, scale does not “hug” the base of the protective flask

• A steatite water heater means that the protective bulb of the dry heating element is covered with the same enamel with an admixture of cobalt and zirconium as the tank walls. As a result, the casing is protected from corrosion, although hard scale cannot fix on it anyway. However, all the same, due to the low intensity of scale formation, the anode manages to almost completely loosen it. The bulk of the flakes from the flask subsequently flies off during the heating of the water and the movement of the hot water mass from the bottom of the boiler to the top.

Protective flask of dry steatite heating element Atlantic

• The walls of the boiler and the protective flask are made of the same steel and covered with the same enamel composition. Therefore, even if the anode fails, the corrosion process does not begin, since the casing and the tank do not form a galvanic pair.
• Over time, conventional boilers can become more and more noisy. The most common reason is that the heating element gradually becomes overgrown with solid scale, which is why loud extraneous sounds appear during water heating. In the case of dry steatite heating elements, as I have already indicated, in principle, solid scale cannot accumulate on the protective flask. As well as in a large volume – loosened, in the form of flakes. Therefore, we can say that boilers with dry steatite heating elements are the quietest among all water heaters.

Disadvantages:

• Boilers with dry steatite heating elements are more expensive compared to copper electric heaters. The difference reaches 30%. However, models with a soapite option are about three times cheaper in maintenance (why – we will figure it out below). In addition, if boilers with wet heating elements, with rare exceptions, belong to the energy efficiency class “C”, then water heaters with a dry “heart” – to a higher class “B”.
• Consumables for “steatite” boilers are more expensive. So, an ordinary wet heating element for 1 W from Atlantic will cost 500 rubles, and a more modern dry one – 1 rubles, which is almost 500% more. But, again, a steatite electric heater needs to be changed every 2 years, while an ordinary wet copper one – on average, once every three years.

Pseudo-dry heating elements… Again, major players like Electrolux and Thermex did not license Atlantic the right to use dry steatite heating elements in their boilers. And at the same time, competitors could not copy the French development cleanly – after all, it was patented! Therefore, other boiler manufacturing companies reasoned as follows. If the consumer needs a dry heating element, an electric heater must be made, which at least formally fits this term.

As a result, the so-called pseudo-dry heating elements appeared. At first glance, this is a more progressive solution in comparison with wet electric heaters. However, upon closer examination, it turns out that in this case “dryness” does not bring any fundamental advantages.

A pseudo-dry heating element can be described as follows: it is a wet heating element, which was simply put into a protective tube sealed from above. In this case, the electric heater does not come into contact with the protective casing, and the space between them is filled only with air.

A flange into which two pseudo-dry heating elements are inserted

Interesting fact. There are no pseudo-dry heating elements with a capacity of more than 1,3 kW. Therefore, in boilers, in order to achieve a power of even 1,5 kW, manufacturers like Electrolux have to install systems as in the picture above – with two electric heaters in a bundle.

There are powerful wet heating elements, even 2,5 kW. But for this, the tube of the electric heater has to be bent in half two or three times. Otherwise, you get a long, irrational construction. Which, due to its height, will also heat hot water in the upper part of the tank. You cannot bend anything in pseudo-dry heating elements – otherwise it will simply not be possible to replace the “hairpin”.

Wet heating element with a power of 2 kW, the tube is bent in three places. If you straighten the heating element, you get a pole about a meter in height. As we remember, pseudo-dry heating elements are the same wet ones, only in an additional protective tube. So the manufacturers have to “reinvent” the bicycle with two heating elements instead of one.

In comparison, Atlantic’s dry steatite electric heaters allow for scalable designs. And to produce boilers with only one heating element, but in a version with a capacity of even 3 kW for 300-liter boilers.

Boiler Atlantic Steatite Central Domestic 300 with dry steatite heating element 3 kW

Advantages:

• As in the case of dry steatite options, there is no direct contact of the heating element with the liquid in the tank. However, this practically does not affect the durability of the electric heater. If wet heating elements are changed on average once every three years, then pseudo-dry ones are changed every 4-5 years. Slightly more than normal wet ones.
• Ease of replacing the heating element, without the need to completely drain the water from the tank and unscrew the flange. This is an indisputable plus, but only at first glance. The fact is that pseudo-dry heating elements, unlike dry steatite ones, do not reduce the amount of scale in comparison with wet models. The load on the magnesium anode remains the same, which means that this element still needs to be changed every year. That is, drain the water and unscrew the flange. In the case of a conventional wet heating element, when replacing the anode, as a rule, at the same time, the electric heater is descaled. This ensures the service of the last about three years, or even longer. So it turns out that a simple replacement of a pseudo-dry heating element does not apply to weighty advantages, since the boiler still requires annual maintenance.
• If the protective tubes of the heating element are covered with enamel, as is the case with the flask of the steatite heating element, this prevents the accumulation of solid scale. And in addition, it will prevent the formation of a galvanic pair “tank-casing” when the anode “burns out”. On the other hand, the question of enamel quality and possible subsequent microcracks remains open. Through which water contacts the flask and develops foci of corrosion. In the absence of enamel, hard scale will accumulate on the tube in the same way as on a wet heating element. Unpleasant consequences are expressed in the possible through-eating of the casing, after which the water fills with a pseudo-dry heating element.

Disadvantages:

• A pseudo-dry heating element does not solve the key problems of wet options, therefore both types of electric heaters (with a conventional wet and with a pseudo-dry heating element) have the same disadvantages. The area of ​​the protective casing barely exceeds the dimensions of the heating element itself, therefore, an extremely high heat release per square centimeter of the heating element surface is still obtained. This means that the formation of scale occurs with increased intensity. So much so that the magnesium anode is not able to fully loosen it. Over time, the heating element becomes covered with a dense hard crust of limescale. Due to this, heat transfer decreases and it takes more and more time to heat water, and therefore electricity. If you miss the timely cleaning of the heating element or its replacement, the electric heater may simply burn out over time.
• The frequency of replacing the magnesium anode remains unchanged, as in a conventional wet heating element – as before once a year against 2-3 years of operation with a dry steatite electric heater.
• Since, in comparison with wet heating in a pseudo-dry heating element, heating comes from the base, there remains a problem with the adhesion of scale from the bottom and a decrease in heat transfer, up to the burnout of the electric heater. More precisely, in this case, a dense layer is formed around the protective tubes. But this does not change the essence – over time, the heating element begins to heat the water longer, the power consumption increases. If you do not clean the tank in time, then, most likely, the heating element will rupture.

Service

Most often, articles on choosing a boiler do not touch upon the topic of subsequent maintenance of water heaters. And completely in vain. Since our people do not like to read not only relevant materials on the Internet, but even complete instructions. Even a water heater does not always know the characteristics. Or he professes the principle of “his own master-lomaster” and has some of his own principles of water heater maintenance. As a rule, something like “works – and okay, it breaks – then we’ll figure it out.”

Often, buyers have no idea about the peculiarities of the boiler’s operation and therefore believe that it is not at all necessary to regularly and on time service the water heater. In fact, calling the master every year – isn’t it too often? Consumers think so, after which they look with surprise at the burnt out heating element, a leaking tank and other consequences of savings. And instead of a couple of thousand rubles, they simply “get” for repairs at half the price of a boiler

Boiler maintenance consists of the following operations.

Timely replacement of the magnesium anode… If you “score” – the consequences depend on the material, the protection of the tank walls and the type of heating element. So, with cheap stainless steel with poor-quality welds, there is a high probability of a quick leak. In the case of an ordinary wet heating element, it will quickly begin to overgrow with solid scale. Consequences – from corrosion of the copper tube to reduced heat generation and failure.

In boilers with conventional wet and pseudo-dry heating elements, the frequency of replacing the anode depends on factors such as water hardness and operating intensity. Some manufacturers recommend checking the anode six months after installing the water heater. To roughly understand the resource of the element and replace it in time. On average, it is required to change the “defender” once a year.

Normal wet heating element after 11 months of operation. Looking at such a photo, you understand that manufacturers like Electrolux for models with wet electric heaters do not just recommend the first service six months after the purchase and installation of the boiler

With modern dry steatite heating elements, replacement, as a rule, is required every three years, that is, three times less often. As I mentioned above, this is due to the much smaller volume of scale. However, Atlantic appears to be reinsured and requires boiler maintenance every two years. As a motivation, the company gives an additional free year of warranty if the user calls the master on time. In total, we get 8 years of warranty versus 7 standard ones. Or another option – you need to buy a set of three anodes and replace it every two years yourself. In this case, similarly, the user receives 8 years of warranty.

Replacing the heating element… With a conventional wet heating element, the state of the element should be assessed when changing the anode. As a rule, if you delay the replacement of the latter, not long before the electric heater burns out. Or the development of banal corrosion.

To install a new “protector”, it is necessary to completely remove the flange, on which the heating element is also installed. So do not be lazy at the same time to clean the electric heater from both hard deposits and scale flakes. It is recommended to change the wet heating element once every three years.

In the case of a pseudo-dry heating element, the electric heater itself should be replaced every four to five years. It is important not to forget to descale the protective tubes in which the “pins” are installed.

According to Atlantic, the service life of a modern dry steatite heating element is at least 20 years. It is not yet possible to check this. Let me remind you that a dry TEN water heater first appeared only in 2012. Nevertheless, in the recommendations for boiler maintenance for a period of 7-8 years, the replacement of the heating element is not assumed. That is, Atlantic claims that the electric heater works smoothly.

Spare parts – is it worth buying original parts?

This subsection was pushed to me by one of the videos on YouTube, which caused the wildest surprise. In it, it seems like a specialist in the selection / maintenance of boilers with a serious look voices such wild things that, as they say, “he says, but I am ashamed.” The bottom line is that the master discusses the choice between the original flange-bulb and the non-original. On one side of the scale – a variation WITHOUT enamel coating and with a thinner stainless steel [of unknown quality and origin]. On the other – the original with enamel and steel walls with a decent thickness.

Extensive reasoning hovers around the topic “Well, the original can fail. Although a non-original spare part too. But the original can. And the other can. ” And such transfusions from empty to empty – about five minutes. I will say briefly – when it comes to pseudo-dry heating elements, protective flasks and flange-flasks for them, you have to be a hefty masochist to get used to non-original spare parts. As a rule – for the sake of saving 10-20% in comparison with branded parts.

Three variants of non-original flanges for Electrolux boilers with pseudo-dry heating elements. On the left – at least a version with enamel. Although its composition, application method are all unanswered questions. It is possible that the enamel layer will quickly crack and peel off. In the center and on the right there are stainless steel tubes of unknown grade and thickness. The copy on the right looks ridiculous. The Chinese did not care so much that they were even too lazy to paint the base of the flange separately, before welding the pipes. Instead, the final design was painted, so at the bottom of the tubes we see sloppy blue streaks

What do we get in return? Without enamel – we immediately prepare for the fact that the flask will become overgrown with hard scale and rust. And given the thin walls, it will leak quickly. After that, the heating element will immediately turn into the queue for replacement. Further, if the boiler tank is not covered with enamel, then in the event of anode failure, galvanic vapor will be guaranteed to form between the walls of the container (or seams) and the “casing”. The consequences depend on the specific case – either the tank or the flask will begin to actively collapse.

It is worth avoiding non-original “casings” for Atlantic boilers. Option number one – the spare part is still covered with enamel. But in the original Atlantic flasks, the enamel used is a special composition with cobalt and zirconium in order to avoid the formation of microcracks when the walls expand or contract under the influence of temperature. A cheaper original of unknown origin, most likely covered with ordinary enamel. With the prospect of fouling with microcracks, through which water will pointwise contact with the walls of the flask, as a result of which foci of corrosion may form.

This is how the original flask for Atlantic boilers with dry steatite heating element looks like

Option number two – flasks without enamel. The situation is the same as with the “casing” for pseudo-dry heating elements. A reference copy for lovers of a kind of “Russian roulette” with corrosion. Only in the event of a bulb leak, most likely, you will still “get” to replace the heating element. So you will have to buy immediately a set of spare parts for at least 3 rubles.

Non-original flask for Atlantic boilers with dry steatite heating element

Therefore, be careful if you go to non-branded stores in search of spare parts, and choose only original products. Otherwise, the scanty savings can turn into large expenses in the future.

Instead of deducing

How to choose a water heater? I examined the main criteria by which the choice of a water heater is made. I hope they will help you find the best model for you depending on your specific needs. If you still have questions or doubts about any aspects – do not hesitate to contact me at schub.alexandr@yandex.ru. Recently, I have the opportunity to promptly receive answers to the most tricky questions from specialists in water heaters of one of the leading European manufacturer of boilers. And we will definitely check the rating of water heaters, or rather their manufacturers, next year.

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