Removal of scale from the heat exchanger of a gas boiler. Why do heat exchangers need periodic cleaning? The better to flush the heat exchanger

The information we offer will help you quickly, accurately and without the help of specialists to carry out regular preventive maintenance of single- or double-circuit gas boilers. The quality of cleaning the heat exchanger double-circuit boiler with your own hands will not be inferior to the work of the service department, for the price - spend no more than 100 rubles, for the time - a maximum of 2 hours. Interesting? Then read on.

A bit of theory

The principle of operation of any gas boiler It consists in heating the coolant during the combustion of gas. The design of the heat exchanger, through which the heated to certain temperature coolant, about the same. It is a curved pipe made of copper or of stainless steel, which is called a coil. When converting gas to thermal energy it heats up and with it water or any other coolant that circulates through the heating system is heated.

A system of plates is responsible for heating the water in the heat exchanger, which is outwardly identical car radiator. With its help, you can increase the temperature of the water, reduce it or send it to one of the circuits, if we are talking about double-circuit boilers.

It is this, relatively speaking, "radiator" of a gas boiler that needs regular cleaning More specifically, flushing.

Why it is necessary to clean the heat exchanger of a gas boiler

The main material for the manufacture of the coil is copper or its alloys. Both in its pure form and as a component, copper has good thermal conductivity, but at the same time, an oxide coating appears quite quickly, which cannot be removed by a non-mechanical method.

Gradually, the layer of copper oxide increases. Reducing the thermal conductivity and lowering the efficiency of the gas boiler. With the same gas consumption, the house will be 15-30% colder in winter.

Gas nozzles also need to be cleaned, through which gas enters the plates and heats the coolant.

Experts recommend that such cleaning of the gas boiler heat exchanger be carried out annually, but in most cases these are preventive measures that justify the service work and the cost of the operation. In fact, it is enough to clean the heat exchanger once every 2-3 years before starting heating season to be completely sure of the correct operation of the boiler and the rational use of fuel.

It is worth paying attention to your kettle. If the plaque is significant and appears quickly after cleaning, the water is hard, and then the heat exchanger will have to be cleaned 1 in 2 years. If not, a 3-year break is enough.

Cleaning - the first stage

First of all, prepare the tools:

screwdriver on "+" and "-";
wrench;
vacuum cleaner;
brush;
gloves.

Depending on the model of the gas boiler, the procedure for accessing the combustion chamber may differ. In some it is enough to remove the cover from front side, unscrew the bolts from the combustion chamber and get to the heat exchanger, in others you have to dismantle sections rubber seal and remove the refractory walls.

As soon as the covers are removed, you can immediately see a mountain of debris at the bottom of the boiler, which is usually sucked in from the street. This area can simply be vacuumed and dust and dirt accumulated during downtime can be wiped off.

Nozzle cleaning

The nozzles are located at the bottom of the chamber, and through them gas for combustion enters the boiler. Be very careful about cleaning, because the worse you do it, the more heat will go past your house. Ideally, all nozzles should become completely transparent. If cleaning is carried out regularly, it is enough to do soft cloth if rarely or even for the first time - a hard brush or a new one will come in handy Toothbrush, lubricated with ordinary toilet soap. Precisely lubricated to soap solution did not prime the injectors.

To clean this node, it must be unscrewed. Adapters are used as connectors, so there should not be any difficulties. Also carefully disconnect the temperature sensor.

First of all, you are engaged in flushing the heat exchanger of the gas boiler from the outside. Take a deep container, pour water and any descaler. If it is not at hand, you can get by with citric acid, but the water should be hot enough - 60-70 degrees. Soak for 40 minutes, then rinse under high pressure with water.

Do not rub the heat exchanger plates with rags, sponges or brushes. This is soft material which is easy to wrinkle.

The best way to clean the boiler heat exchanger is a manual car wash, but you need to control the power of the jet so that the plates remain intact.

You can even prevent the upper part of the assembly from drying out and proceed directly to cleaning the “insides”, more precisely the coil through which the heat exchanger circulates. As a rule, if there is soft water in the room, a significant amount of scale does not have time to accumulate inside during the time between services, but in principle it can be, so the pipe should also be thoroughly cleaned. By the way, the rate of scale formation and lime deposits household filters do not affect.

How to wash the heat exchanger of a gas boiler

If the outer part is easy to handle even household remedy from scale, then to clean the inside of the pipe you will need a more serious preparation, but also from a number of household ones.

Cilit has proven itself well for cleaning toilets, removing plaque. The agent must be liquid and thick to fill the entire pipe. Then it is necessary to flush the pipe with any decalcifying agent or the same citric acid at the rate of 30 grams per liter of water. Pour into the pipe and leave for a few minutes, take it out, shake it powerfully several times, and then thoroughly rinse it 10 times under a large stream of water to completely wash off all the remnants of scale.

On the video you can see clearly how to properly and how to clean the heat exchanger of a double-circuit gas boiler:

After. once you have cleaned the heat exchanger from all sides, dry it and reassemble it in reverse order.

For those who have decided to do “cleaning” for the first time, we recommend filming the whole process or taking photos during the parsing process. It will be much easier to collect later and will not appear unnecessary details, as is often the case.

Connect the heat exchanger to the boiler and the temperature sensor and turn it on at full power. It should be checked how well it works and during which time the coolant has heated up.

This completes the process. Total spent - 62 rubles for citric acid and 2 hours of time. For comparison, in Moscow the cost of this front of work will cost an average of 1000 rubles, in Kirov - from 300 to 500, depending on the model of the boiler.

- scale formed on the heat exchanger, the cleaning and washing of which has to be done periodically. With an increase in the layer, the efficiency of the boiler decreases. To improve performance, you have to increase the power. This increases fuel consumption and accelerates the wear of the unit.

The scale layer prevents the complete cooling of the heat exchanger. At one point, the unit will fail, or burn out from overload circulation pump. How is the heat exchanger flushed, what means can be used?

A signal for the user that it is time to clean the boiler - a decrease in heat transfer, an increase in gas consumption (). But it’s better not to bring it up to this: the thicker the layer of pollution, the more difficult it will be to deal with it on your own, and cleaning by professionals will cost a pretty penny.

Under normal conditions, do-it-yourself cleaning of the heat exchanger of a double-circuit boiler is carried out every two years (). If the water is hard - more often. Particular attention is paid to the secondary heat exchanger through which hard tap water passes.

The second mandatory action is the removal of soot that is deposited on outer surface heat exchanger housing. There are no strict recommendations about the frequency of cleaning here - the amount of soot depends on the quality of the gas used, on the efficiency of the supply filters, on design features boiler, etc.

The need for cleaning can be determined visually, or this work can be done at the same time as internal flushing. Large accumulations of scale and soot in the aggregate can reduce the thermal efficiency of the boiler by half.

If antifreeze is used instead of water in the heating circuit, the frequency of cleaning depends on its brand: some anti-freeze liquids contain chemical components that counteract the accumulation of plaque.

How to clean the heat exchanger of a double-circuit boiler and how often this should be done is indicated in the instructions for the model. But these recommendations are usually designed for ideal conditions operation (composition of water, etc.), which in real life usually doesn't happen.

Cleaning methods

How to flush the heat exchanger of a double-circuit boiler at home? In some cases, disassembly of the unit is required, while others can be dispensed with. The purpose of dismantling is to provide access to the heating element. When cleaning with disassembly, you can do minimal cost, but this option is long and laborious.

Sometimes partial disassembly is performed - for example, to clean soot from the fire-tube heat exchanger of a floor-standing boiler. The heat exchanger itself cannot be dismantled at home, they free access to it: they also remove the cover with the chimney outlet pipe.

How to remove the heat exchanger from a wall-mounted gas boiler? First, the electrical unit is de-energized, the water supply is shut off, water is drained from both circuits and the expansion tank. After that, the heat exchanger is dismantled.

flushing

How to clean the heat exchanger of a gas boiler from scale with your own hands? With a small amount of plaque inside, you can do with manual washing using a solution of citric acid.

In case of a thick layer of scale, a flushing plant will be required to circulate detergent for a few hours. For this purpose, a 10-liter tank with a pump is suitable (you can use a circulation pump from the circuit). Two hoses from the pump are connected to two pipes of the heat exchanger.

There are three cleaning methods:

mechanical;
chemical;
hydrodynamic.

In the first case, a brush, scraper, vacuum cleaner can be used to remove plaque. Heat exchanger parts are pre-soaked in solutions of cleaning agents.

During chemical treatment, an acid wash solution is pumped into the system using a booster and driven through a heat exchanger for several hours. Acidic solutions remove iron and carbonate deposits well. At the end of cleaning, the agent is drained and a neutralizing agent is poured.

The hydrodynamic method is the injection of water with abrasives into the system under pressure. Thus, the internal surfaces are cleaned mechanically, but the cleaning efficiency is higher than when processing manually. Flushing can be performed without dismantling the system, but it is quite expensive. When self-cleaning, you need to monitor the pressure in the circuits to avoid rupture of the heat exchanger.

Chemical compositions

How to flush the heat exchanger of a gas boiler? Most safe option – lemon acid. Industrial products for washing the gas boiler heat exchanger - Cillit, DETEX, Sanaks.

Hydrochloric acid is more effective. But its use is more dangerous for both the user and the system. Concentrated acid can destroy the internal protective layer of the heat exchanger, as well as increase the brittleness of the metal.

External processing of contaminated parts is carried out by special compositions to remove soot and carbon deposits. In extreme cases, you can use household detergents.

Video about flushing the heat exchanger of a gas boiler.

It is best not to carry out the work yourself, because it is likely that due to the lack necessary experience instead of cleaning the boiler from scale, you will have to purchase a new boiler. In the article, we will talk about how important timely cleaning of the boiler is. We will also tell you what is traditionally included in such a procedure.

Cleaning methods

Boiler cleaning involves a standard set of separate methods, which includes both mechanical and chemical cleaning. Another possible way out - pre-cleaning boiler from the dirt that in the future may settle on its walls. Since preliminary operations are very expensive, they are now rarely preferred. Regular cleaning of the boiler from the formed scale is enough to prevent the occurrence of possible emergencies. Much more expensive will be the consequences of the lack of timely descaling, when things can end up not just repair work, but also a complete replacement of heating equipment.

Reagent cleaning of boilers from the formed scale

Such cleaning traditionally includes methods that involve surface treatment chemical reagents(where the name comes from). Among such reagents, strong acids are currently especially popular, because they cope with such common types of scale as carbonate and ferruginous with great efficiency. Used for cleaning boilers from scale and other solutions. So, silicate scale can be easily removed if you turn to solutions with high alkalinity for help. In any case, it is very important to choose a washing agent on an individual basis, because the choice is influenced by both the nature of the pollutant and the properties of the pollutant.

Varieties of chemical cleaning

An important step in flushing boilers indiscriminately is the supply of a cleaning solution to the system. The booster pump is responsible for this task. It is very important to be able to regulate the system pressure, because this is associated not only with the supply of cleaning solution, but also with an increase in pressure during the reaction between plaque and acid.

In the case of collapsible cleaning, the system is initially dismantled, and dirty parts are placed in separate container with a solution. After that, the elements are washed and reassembled into a single whole. Traditionally, chemical cleaning of the described dismantling type is carried out together with mechanical descaling. It is best to refer to such an operation if the scale has become significant.

Physical cleaning methods

If we are talking about cleaning the boiler from scale in the complex, then mechanical cleaning is initially performed, and only then chemical. Among the main disadvantages of the physical method, one can single out the fact that the inner surface of the boiler is negatively affected, therefore it quickly deteriorates, especially if too sharp tools are picked up by carelessness. Once the cleaning of the boiler is completed, it is important to thoroughly rinse all removed parts with water and reassemble them correctly.

Hydrodynamic cleaning of the boiler heat exchanger involves the removal of contaminants by means of a jet of water high pressure. This method differs from the mechanical one in that it excludes any kind of damage to parts. Although hydrodynamics is very efficient, it is not used as often due to its high cost.

Separate two ways physical methods cleaning the boilers from the formed scale. Both options involve without fail analysis of the system, which means that it is extremely important for anyone who is interested in such work to acquire necessary tools and provide complete equipment. Since scale is formed mainly on the surfaces of the boiler from the inside, it is impossible to interact with contaminated areas directly. Since the disassembly of the system is a time-consuming and complex process, the cost of physically cleaning the devices from scale is also high.

Boiler cleaning - compulsory procedure which must be carried out regularly. In this case, you need to know how to clean the gas boiler from soot and scale. Scale is collected in the passages of the heat exchanger, and soot is collected in the flue channels of the boiler itself and the chimney. Thus, in order to keep the heating equipment in working order, it is necessary to clean both the heat exchanger and smoke channels, as well as a flue and a burner.

How to clean the heat exchanger?

The cleaning of the heat exchanger depends on its design and on what water is used in the system: prepared - with special additives or unprepared.

By design, the heat exchanger can be one of three types:

bithermic;
lamellar;
fire tube.

Lamellar are further subdivided into two types - primary and secondary (for heating water). The fire tube heat exchanger is installed in floor standing boilers, and bithermic - in compact mounted or floor models.

Cleaning can be done in the following ways:

mechanical;
chemical;
electric discharge;
hydrodynamic,

Service gas equipment, including boilers, must be carried out by specialists with appropriate education. If you do not have enough technical skills, it is better to invite the master.

How to clean the fire tube heat exchanger of a single-circuit boiler?

Cleaning floor-standing boilers with a fire-tube heat exchanger differs from the same procedure for attachments. Here, for the procedure, the heat exchanger is not removed, but only access to it is provided.

To perform the work you will need the following tools:

wrenches;
metal brush-ruff;
manual brush for metal;
screwdriver;
brush made of natural pile or nylon.

The first mandatory action is to turn off the gas supply valve. Next, you need to perform three stages of work - providing access to the heat exchanger, cleaning parts, assembling the boiler. The disassembly / assembly steps depend on the specific model. How to clean the boilers of the MAYAK - 12 KS model, you can see in detail in the video.

Cleaning of double-circuit boilers

For boilers with a circuit for heating water, it is mandatory to flush the secondary heat exchanger from scale inside. Moreover, its cleaning should be carried out more often, since a stream of unprepared water passes through it and hardness salts (mineral deposits) actively settle on the walls. The same applies to bithermic heat exchangers. Cleaning of double-circuit boilers is carried out in two stages. The first is mechanical cleaning of the outer surface of parts and chimneys from soot, the second is chemical, hydrodynamic or electric discharge descaling.

Mechanical cleaning of plate heat exchangers

It is possible to clean the boiler from soot without removing the heat exchanger. To do this, just remove the cover, arm yourself with a stiff nylon brush and close the gas nozzles so that dirt does not get there. The whole process is clearly shown in the video:

If the soot has stuck to the surface and is not removed during mechanical processing with a brush, then the heat exchanger is removed and soaked in special washing solutions for several hours. Such products are commercially available in a wide range, such as Fauch and MAZBIT +. But you can also use household chemicals– gels for cleaning grills, ovens.

Before dismantling the boiler, you must disconnect it from the gas, and the igniter from the electricity. In addition, it is necessary to drain the water from both circuits and expansion tank. The secondary heat exchanger is removed first, it is located immediately behind the boiler cover. It is more problematic to remove the primary (main) one, since you will have to disassemble the combustion chamber.

How to clean interior surfaces?

flushing inner surface plate, fire tube or bithermic heat exchanger is possible only with the help of special equipment.

High pressure pump- hydrodynamic washing. Used to remove small deposits. Advantages - the speed of the procedure and the possibility of cleaning without removing the heat exchanger.
Booster (acid resistant pump)– acid (chemical) washing. Removes even old scale. Benefits - removes scale that cannot be removed by other methods. Disadvantages - with the wrong selection of reagents (acids and neutralizers), it reduces the service life of the heat exchanger.
Complex "Streamer" for electric discharge cleaning. Used to remove scale of any strength. Advantages - the metal of the heat exchanger is not destroyed, it is provided high degree cleaning. Disadvantages - noise and duration of the procedure.

Of all the methods listed at home, only chemical cleaning is possible, since the factory booster can be replaced with a low-pressure pump. The rest of the equipment is both expensive and bulky, so such washing of boilers can only be done by service centers.

Chemical cleaning

In the presence of a booster, flushing can be performed independently. You can make a booster with your own hands - this is a pump and a 10-liter container with two hoses. So that the procedure helps to remove scale, but does not damage metal surface, it is important to choose the right acid. If the boiler is cleaned regularly, there are small deposits on the pipes, then the best way out is to use citric acid. The concentration of the solution is up to 200 g of acid per 5 liters of water.

If the scale is old or unprepared water with a high mineral content (hard water) is used, more radical means should be taken - compounds based on orthophosphoric, sulfuric or hydrochloric acid. The use of a hydrochloric acid solution without corrosion inhibitors is not recommended as it may damage the equipment.

After acid treatment, it is imperative to flush the heat exchanger with a neutralizer. The alkaline composition is selected based on the acid used. For example, after citric acid, ordinary baking soda. If you buy a flushing liquid, then it is better to immediately purchase a neutralizer for it: usually companies that produce acidic formulations also offer alkaline ones for neutralization.

Flushing video:

How often should the boiler be cleaned?

The technical documentation for the boiler indicates how often it needs to be serviced. For closed circuits with addition of reagents ( single-circuit boilers heating) cleaning is required less frequently. It can be performed 1 time in 2-3 years. The bithermic and secondary heat exchangers must be flushed every year, and if difficult conditions operation ("bad" composition of water) - twice a year.

Signs that the boiler urgently needs cleaning:

the boiler is slowly gaining temperature;
insufficient traction;
the burner does not ignite or does not burn well;
with the same gas consumption, the heat output is less;
traces of soot or partially burnt paint in the area of \u200b\u200bthe viewing window.

Don't neglect preventive measures, because the result of this can be not only broken equipment, but also a threat to the safety of all residents of the house. Clogged chimneys and pipes with growths inside can cause serious accidents.

Heating boiler, like almost any technological equipment working in difficult conditions, needs periodic maintenance. One of the most important operations carried out during the maintenance of a gas boiler is the cleaning of its heat exchanger.

Why is it needed

heat exchanger is a metal (or cast iron) box with a built-in radiator, which is heated from the outside by a burner flame and transfers heat to the liquid flowing inside. If the heat exchanger is clean, then it works with maximum efficiency, giving almost all the energy received for heating. However, over time, various impurities begin to precipitate on the walls of the internal channels, which are compounds of salts dissolved in the coolant (scale). The formation of lime deposits is especially intensive in the secondary heat exchanger of a double-circuit boiler if hard water is used in the DHW line.

Such contamination of the heat exchanger channels can lead to a number of unpleasant consequences:

Reduced boiler efficiency. mineral deposits they have much lower thermal conductivity than metal, so much more energy will have to be spent on heating water. Accordingly, the gas consumption will also increase.
Overheating of the heat exchanger. The scheme of operation of gas boilers assumes that the coolant coming from the return line cools the internal cavities heating element. When scale appears, the cooling efficiency drops, the heat exchanger overheats and quickly fails.
Breaking heating equipment. Mineral deposits on the inner walls of the heat exchangers make it difficult for the coolant to pass through them. This creates an additional load on the circulation pump, which will quickly exhaust its resource if the narrowed channels are not cleaned in time.

Thus, timely flushing of the heat exchanger will help save significant funds by preventing the breakdown of expensive components and ensuring minimal required flow fuel.

Frequency of cleaning the heat exchanger

In different sources, you can find rather conflicting information about how often cleaning should be carried out. various elements heating boilers. As a rule, maintenance intervals are given in the instructions for a particular model. However, please note that these figures are approximate and are intended for use in the most favorable conditions. In fact, flushing of heat exchangers may be required more frequently.

It is possible to assess how heavily the heat exchanger is clogged by several indirect signs that accompany the operation of a gas boiler:

Gas consumption has grown significantly. Practice shows that the increase in fuel consumption due to deposits inside the heating element can be up to 15%;

This is what the heat exchanger looks like after intensive use

The performance of the heating system has decreased. Long warm-up of heating radiators, low temperature coolant in the return, a constantly on burner - all this may indicate that it is time to flush the heat exchanger;

Low pressure in the faucet. barely warm water in the DHW system, they also often talk about possible problems heat exchangers of a double-circuit boiler;

A large load on the circulation pump, noise or obvious signs of interruptions in its operation are also a signal that the system needs to be flushed.

The design of modern boilers is designed for long-term use, and the cost of spare parts for them is quite high. Therefore, the heat exchanger should be cleaned immediately when the symptoms described above appear. Otherwise, the cost of maintaining heating boilers can increase significantly.

Methods for cleaning heat exchangers

The heat exchanger can be flushed different ways. Next, we will consider them in more detail, and at the same time we will note how to clean the heat exchanger of a double-circuit boiler, which is especially prone to the formation of organic deposits.

Manual cleaning

To solve the problem in this way, the heat exchanger must be completely removed from the boiler in order to gain free access to it. After that, it can be cleaned with various tools:

mechanical cleaning. You can remove plaque from the inner surface with a hard metal brush or a special scraper;
flushingin special formulations . Most often, heat exchanger parts are soaked in an acid wash solution. This method is especially effective for removing stubborn dirt, for example, in the channels of double-circuit gas boilers.

Method manual cleaning simple and effective. It can be used to flush the heat exchanger yourself. The only remark is that it is necessary to be careful when working with the sealing elements of the boilers and monitor the tightness of all connections.

Hydrodynamic cleaning

Flushing of heat exchangers of a gas boiler can be carried out without disassembling it.

Hydrodynamic cleaning is a process mechanical removal scale from the walls of pipelines using high-pressure water jets, which sometimes contain impurities of small abrasive particles.

Such a procedure is carried out with the help of special installations that pump pressure up to one and a half thousand bar in the line. This is the most effective, although quite expensive, way to clean heat exchangers.

Chemical cleaning

Chemical washing of elements of gas boilers consists in the fact that an acid washing solution is introduced into the system using a special device called a booster. Then this solution is run through the heat exchanger for several hours and cleans it. This method allows you to remove the most complex types deposits - carbonate scale and ferric iron.

Heat exchanger before and after cleaning

To disadvantages chemical cleaning include the high cost of the reagent, the wear of the metal and the large volume of toxic waste.

Fluids for flushing heat exchangers

In conclusion, consider the question of how to flush the heat exchanger of a gas boiler. Despite the abundance of recommendations in various sources, some care must be taken in choosing a cleaning agent.

Many experts recommend using hydrochloric acid for flushing. It removes scale really well, but is a rather aggressive compound that can disrupt protective covering inner surface of the heat exchanger.

In addition, there is evidence that flushing hydrochloric acid can cause metal brittleness.

Less dangerous for the heat exchanger material is citric acid. It copes well with all types of deposits, as well as special reagents: DETEX, Cillit, Sanaks and others.

timely and proper care behind the elements of the heating system will increase its service life and reduce the cost of maintaining performance. Cleaning the heat exchanger, as one of the most important operations performed during maintenance boilers, will make the most significant contribution to this process.