The information we offer will help you quickly, accurately and without the help of specialists to carry out regular maintenance of single- or double-circuit gas boilers. In terms of quality, cleaning the heat exchanger of a double-circuit boiler with your own hands will not be inferior to the work of the service department, in terms of price - you will spend no more than 100 rubles, in time - a maximum of 2 hours. Interesting? Then read on.
A little theory
The operating principle of any gas boiler is to heat the coolant during gas combustion. The design of the heat exchanger, through which the coolant heated to a certain temperature moves, is approximately the same. This is a curved pipe made of copper or stainless steel, which is called a coil. When gas is converted into thermal energy, it heats up and along with it, water or any other coolant that circulates through the heating system is heated.
A system of plates, which is externally identical to a car radiator, is responsible for heating the water in the heat exchanger. With its help, you can increase the water temperature, reduce it, or direct 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, or rather, flushing.
Why do you need to clean the heat exchanger of a gas boiler?
The main material for making 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 a coating of oxide appears quite quickly, which cannot be removed without mechanically.
Gradually the layer of copper oxide increases. Reducing thermal conductivity and reducing the efficiency of a gas boiler. With the same gas consumption, the house will be 15-30% colder in winter.
They also need cleaning gas injectors, through which gas enters the plates and heats the coolant.
Experts recommend carrying out such cleaning of the gas boiler heat exchanger annually, but in most cases these are preventive measures that justify the work of the service department 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 confident in the proper operation of the boiler and rational fuel consumption.
It's worth paying attention to your kettle. If the deposit is significant and appears quickly after cleaning, the water is hard, and then the heat exchanger will have to be cleaned every 2 years. If not, a 3-year break is enough.
Cleaning - the first stage
First of all, prepare your tools:
- screwdriver for “+” and “-”;
- adjustable wrench;
- vacuum cleaner;
- brush;
- gloves.
Depending on the gas boiler model, the procedure for accessing the combustion chamber may differ. In some, it is enough to remove the cover from the 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 fireproof 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 drawn in from the street. This area can simply be vacuumed and wiped away any dust and dirt that has accumulated during downtime.
Cleaning the injectors
The nozzles are located at the bottom of the chamber, and through them gas enters the boiler for combustion. Be very careful when cleaning, as the worse you do it, the more heat will escape from your home. Ideally, all injectors should become completely transparent. If cleaning is carried out regularly, it is enough to get by soft cloth, if rarely or even for the first time, a hard brush or a new toothbrush, lubricated with ordinary toilet soap, will come in handy. Precisely lubricated so that soap solution I didn't fill the injectors.
To clean this unit, 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 descaling agent. If you don’t have it on hand, you can get by with citric acid, but the water should be hot enough - 60-70 degrees. Soak for 40 minutes, then rinse off under high pressure of water.
Do not rub the heat exchanger plates with rags, sponges, or brushes. This soft material, which is easy to wrinkle.
The best way to wash the boiler heat exchanger is with a hand car wash, but you need to control the power of the jet so that the plates remain intact.
You can even not let the upper part of the unit dry out and proceed directly to cleaning the “insides,” or rather 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 exist, so the pipe should also be thoroughly cleaned. By the way, the speed of scale appearance and lime deposits household filters have no effect.
How to clean the heat exchanger of a gas boiler
If the external part can be easily handled even household product from scale, then to clean the inside of the pipe you will need a more serious preparation, but also from a number of household products.
Cilit has proven itself well for cleaning toilets, removing plaque. The product should be liquid and thick enough to fill the entire pipe. Then you need to rinse the pipe with any decalcifying agent or the same citric acid at the rate of 30 grams per liter of water. Pour it into the pipe and leave it for a few minutes, take it out, shake it vigorously several times, and then rinse thoroughly under a large stream of water 10 times to completely wash off all remaining scale.
In the video you can see clearly how to properly and how to clean the heat exchanger of a double-circuit gas boiler:
After that. Once you have cleaned the heat exchanger from all sides, dry it and reassemble it in the reverse order.
For those who have decided to start cleaning for the first time, we recommend filming the entire process or taking photos during the cleaning process. It will be much easier to assemble later and unnecessary parts will not appear, as often happens.
Connect the heat exchanger to the boiler and temperature sensor and turn it on at full power. You should check how well it works and how long it took for the coolant to heat up.
This completes the process. Total spent - 62 rubles for citric acid and 2 hours time. For comparison, in Moscow the cost of this scope of work will cost an average of 1000 rubles, in Kirov - from 300 to 500, depending on the boiler model.
A good owner always makes sure that his home is warm and cozy, especially on cold winter evenings.
Most the best option home heating is heating system With . Therefore, it will not be a secret to anyone that the warmth and comfort in the house will depend on the stable operation of this boiler unit.
In order for a gas boiler to function normally, it is necessary to carry out regular maintenance of this unit, which consists of cleaning all components and parts from contamination. (Read more about how to clean a gas boiler from soot.
One of the important structural elements of a gas boiler unit is the heat exchanger, from technical condition which depends on the functioning of the boiler as a whole. In this article we will talk about what a heat exchanger is, as well as what methods can be used to flush it.
What is a heat exchanger
This device is a small pipe structure through which the coolant moves. Heat exchanger in gas boiler located just above the firebox.
This was done in order to thermal energy, obtained from the combustion of gas, passed through it, and, accordingly, heated.
Thus, hot water passes through the heat exchanger, which may contain various impurities in the form of metal salts and lime particles. These chemicals constantly deposit on the inner walls of the pipes, forming a coating.(Read about this in this article).
Over time, this type of pollution only increases, as a result of which the movement of water through the heat exchanger becomes difficult, which leads to failures of the entire boiler unit as a whole. Therefore, it is very important to flush the gas boiler regularly.
How often should the heat exchanger be cleaned?
Many Internet sources on this topic provide very conflicting information regarding the frequency of cleaning the heat exchanger. Some of them advise following the manufacturer’s instructions, others rely on the opinions of experts.
Maybe they are all right, but most real option it will be that The heat exchanger should be flushed when the following symptoms begin to appear:
- the burner in the gas boiler is on all the time;
- the circulation pump operates with a characteristic hum, which indicates overload;
- heating of radiators takes much longer than usual;
- gas consumption has increased significantly with the same operation of the boiler unit;
- weak pressure hot water in the tap (this sign is applicable for double-circuit boilers).
All these points strictly indicate that problems have arisen in the functioning of the heat exchanger, and this, in turn, means that it is necessary to start flushing.
Specialist's note: Irregular cleaning of the device will reduce the efficiency of the gas boiler.
How to clean
Many ordinary people who decide to flush the heat exchanger with their own hands, as a rule, ask two questions. How to clean this device? How to clean it? First, let's tell you what chemicals are used to flush the heat exchanger.
Cleaning products
Modern market household chemical reagents are very well saturated with all kinds of means for cleaning a gas boiler.
Therefore, you need to be very careful when choosing a cleaning agent. First of all, you need to consider the following factors:
- degree of heat exchanger contamination;
- how the reagent will affect the material from which the heat exchanger is made.
At home, it is most advisable to use the following chemicals to flush this boiler element:
- citric acid, which is sufficient effective means to remove scale;
- sulfamic and adipic acids are practical for regular washing of the heat exchanger, when the contamination is not so significant;
- hydrochloric acid is designed to remove enough strong scale, but when using it, it is worth taking into account the properties of the heat exchanger material;
- gels that dissolve in water - they are not as aggressive as acidic reagents, but no less effective.
Important point: All safety precautions must be observed when working with chemicals.
Washing methods
To clean this yourself structural element boiler from scale, it is optimal to use the following two methods:
- mechanical;
- chemical.
The essence of the mechanical method is as follows:
To successfully clean the heat exchanger from scale using a booster, flushing should be done several times. And in conclusion, I would like to note that we actually indicated two effective ways from pollution. We hope that our recommendations will help you wash the heat exchanger yourself at home.
Watch the video in which an experienced user clearly explains the features of flushing the heat exchanger of a gas boiler:
About the dangers of scale in a heat exchanger
Heating of tap water for a hot water supply (DHW) system in a double-circuit gas boiler or in a gas water heater is carried out in a flow-through heat exchanger.
It is known that when heated above 54 o C crystallization of salts dissolved in water occurs chemical elements, mainly calcium and magnesium. Solid salt crystals settle on the heating surfaces of the heat exchanger and form a strong crust on them.
In addition to hardness salts, scale deposits include other solid particles found in water. For example, rust particles, oxides of other metals, sand, silt, etc.
The amount of salt in water determines the degree of its hardness. There are hard water, which contains a lot of salt, and soft water, with a small amount of salt.
If the source of tap water is a river or other natural body of water, then the hardness of such water is usually low. You are lucky, the water in your home is soft.
Tap water from a well usually contains more hardness salts. And the deeper the well, the more salt there is in the water.
A hard crust of hardness salts, rust, sand, silt on the heating surface of the heat exchanger prevents the transfer of heat through its metal walls. In addition, deposits reduce the clearance of the heat exchanger channels. As a result the heating temperature and pressure of hot water gradually decreases, and the walls of the heat exchanger overheat, which reduces its service life.
The internal structure of a double-circuit gas boiler using the example of Protherm Gepard 23 MTV and Panther 25.30 KTV (Panther). The secondary DHW heat exchanger is located in the lower compartment.
Dual-circuit gas boilers most often have two heat exchangers. One is the primary one, in which water is heated with gas for heating. The other is the secondary DHW heat exchanger, in which heating water from the primary heat exchanger heats the DHW water from the mains.
There are also double-circuit boilers, in which both water for heating and water for domestic hot water are heated by gas in one combined bithermic heat exchanger. A bithermic heat exchanger accumulates scale faster, and it is more difficult to clean it from scale.
The geyser has one DHW heat exchanger, in which tap water immediately heated by gas.
Regular descaling is only necessary for the DHW heat exchanger, in which there is a constant accumulation of deposits of hardness salts.
In the channels of heat exchangers with heating water, scale accumulation occurs only when fresh water is replaced or added to the system. This happens quite rarely and in small volumes.
If there is a filter at the inlet of the heating water boiler, then other dirt from the heating system does not enter the boiler and there may be no need to clean the boiler coolant channels during its entire service life. It is not necessary to descale the primary heat exchanger at the same intervals as the DHW heat exchanger. However, “servicemen”, without proper reason, often insist on descaling the primary heat exchanger, at the same time, just in case. Naturally, they charge for this.
Secondary plate heat exchanger for hot water supply of a double-circuit gas boiler. Two holes serve to circulate heating water through the heat exchanger. Through the other two, cold water enters and heated hot water exits. Regular descaling of the inside is required. 
Bithermic heat exchanger of a double-circuit gas boiler. On the right are pipes for heating water. On the left are pipes for DHW water.Requires regular cleaning of scale inside and soot outside. 
Heat exchanger for DHW gas water heater. Regular cleaning of scale inside and soot outside is required.
How often to descale the heat exchanger
Equipment manufacturers require maintenance of a gas boiler or geyser be held annually.
Some "owners" do not approach the equipment until something happens. But, as a rule, it “happens” at the most inopportune moment. The severity of the damage and the cost of repairs are higher. Some defects, which are outwardly invisible, lead to an increase in gas consumption over a long period of time.
In the Russian Federation, there are “Rules for the use of gas in terms of ensuring safety during the use and maintenance of in-house and intra-apartment equipment when providing public gas supply services”, approved by Decree of the Government of the Russian Federation No. 410 of May 14, 2013.
In accordance with current rules, in order to ensure the safety of gas-using equipment, household consumers must enter into a maintenance agreement with a specialized organization.
In December 2016, the Code of the Russian Federation on Administrative Offenses was supplemented with Article 9.23, which provides for punishment in the form of a fine of up to 30 thousand rubles for individuals, for violation of security rules safe use and maintenance of intra-house and intra-apartment gas equipment.
Fines are provided for:
- avoidance of concluding a mandatory contract for the maintenance and repair of gas equipment in homes;
- refusal to admit a representative of the organization to perform maintenance; avoidance of concluding an agreement on the performance of work on diagnosing gas equipment;
- avoidance of replacing gas equipment; actions that led to an accident or an immediate threat of harm to human life and health;
- untimely or poor quality work on maintenance and repair of in-house or in-apartment gas equipment.
I do not advise home craftsmen to carry out work on the gas duct of the boiler or heater. A home handyman can do some if necessary simple work which are recommended to be performed when maintenance boiler
The bithermic heat exchanger of a gas boiler, as well as the heat exchanger of a geyser, must be regularly cleaned not only of scale inside, but also of soot deposits outside.
A home craftsman can easily clean the DHW heat exchanger of scale inside and soot outside with his own hands.
Depending on the degree of hardness of tap water, the amount of water used and its heating temperature, the heat exchanger must be cleaned of scale at intervals of 1 to 5 years.
I advise you to do this work annually, in the summer. You should not wait several years until the heat exchanger is covered with a thick layer of scale inside and overgrown with soot on the outside.
You will have to pay for a thick layer of scale and soot with increased gas consumption and reduced equipment durability. In addition, a thin layer of dirt can be removed much easier.
Methods for descaling a heat exchanger
Heat exchangers are cleaned of scale by exposing the deposits to special liquid formulations, which dissolve salt, release and wash out rust, sand and other insoluble particles.
For a double-circuit gas boiler (column) use There are two fundamental ways to descale a DHW heat exchanger:
- With removal and dismantling of the heat exchanger from the boiler, column.
- Without removing the heat exchanger from the boiler or gas water heater.
An acid solution is poured into the heat exchanger removed from the boiler or column. Happening chemical reaction, as a result of which the scale dissolves. The intensity of the reaction increases if the heat exchanger with the filled solution is heated. The cleaning process can be made more complete and faster by connecting the removed heat exchanger to pumping unit, which will force the cleaning solution to circulate in the heat exchanger channels.
The second method requires connection to the boiler special equipment which includes pumps, solution containers, filters, hoses, connecting fittings.
The cleaning unit is connected to the boiler inlet pipes. The cleaning solution circulates under pressure in the heat exchanger, dissolving and washing away contaminants.
This method is usually used by enterprises and organizations that provide services to the public.
The best cleaning quality can be obtained if you order the work from specialists.
You can remove the heat exchanger from the boiler yourself and take it to a boiler repair service to remove scale. This service will cost less than calling a technician to your home. And the quality of cleaning using professional equipment will be higher.
It is easier to remove scale yourself if you remove the heat exchanger from the boiler. Home cleaning is suitable for heat exchangers that have not yet boiled too much. It is beneficial not to delay cleaning.
How to remove a heat exchanger from a gas boiler, column
For all brands of boilers and gas hot water heaters, the heat exchanger is removed in different ways. But this procedure usually does not present any particular difficulties. No special tool is required. But it will be better to find instructions, a website, pictures or videos on the Internet on this topic. For the first time, you can invite a service specialist and watch how he removes the heat exchanger.
An example for a double-circuit gas boiler Protherm Gepard 23 MTV and Panther 25.30 KTV (Panther).
To remove the secondary DHW heat exchanger, you need to unscrew two screws - shown by red arrows and remove both mounting rails (at the bottom of the figure). Flow sensor(flow) of hot water DHW is shown by a green arrow. Example for a double-circuit gas boiler Protherm Gepard and Panther. The body of the plate heat exchanger is pressed to the base by mounting rails. After the tires are removed, pull the heat exchanger up and remove it.
Before removing the heat exchanger, it is necessary to empty the boiler of water. To do this, close the taps at the entrance to the boiler of the heating pipes (direct and return). Close the inlet valve cold water and disconnect the cold water tube from the boiler. Water will drain from the boiler through the open cold water pipe. Open the hot water taps to completely empty the DHW tract of water. Open the drain valve on the boiler, on the right under the pump, to drain the heating water.
When reinstalling, check the correct location of the heat exchanger - the marking inscriptions on its side wall should face forward.
1 — mounting rails, heat exchanger holders; 2 — holder screw; 3 - gasket; 4 - heating water filter at the inlet to the heat exchanger; 5 - DHW heat exchanger of a gas boiler; 
Clean the filter in the heat exchanger inlet pipe on the left, closer to back wall. 1 - gasket; 2 - filter;
Before installing the heat exchanger in place, do not forget to clean the filter, item 2, which is located in the inlet pipe of the heat exchanger on the side of the heating circuit (on the left, closer to the rear wall).
It is recommended to change the gaskets between the heat exchanger and the base, item 1, each time during installation. DHW heat exchanger gasket, rubber ring: 22.2x13.5x5 mm. There is a circular recess on the inside. Article number: 0020014166 (10 pieces).
How to remove scale from a heat exchanger
To descale at home, a 20% solution of citric acid (250) is often used as a cleaning liquid. g/liter).
You can also use commercially available special compositions to descale household washing and washing machines. dishwashers. Read the contents of the packaging carefully. The chemical should be designed to remove scale deposits, not to soften water (not to prevent scale deposits).
Less accessible, but if desired, you can find and buy special compositions (liquid or powder) for professional cleaning of boiler heat exchangers from scale. The selection of such chemicals should be done with caution. There is a wide range of strong cleaning chemicals available on the market. different types equipment. You can buy a chemical that will corrode the metal or protective coating of the heat exchanger.
Particular care should be taken when choosing a product for cleaning the heat exchanger without removing it from the boiler. Selected chemical composition should not damage not only the metal of the heat exchanger, but also boiler parts made of other metals, as well as parts made of rubber and plastic.
In order not to make a mistake in choosing, home handyman I recommend using a relatively chemically weak and therefore safe, time-tested, accessible and cheap chemical - food grade or industrial citric acid.
If deposits do not accumulate, then to regularly clean the heat exchanger from scale, you can even use conventional toilet treatment products containing acid, for example, oxalic acid.
Removing scale by pouring a cleaning solution into the heat exchanger
Watch the video that shows how to remove and descale the secondary DHW heat exchanger gas boiler "Ariston".
Here, To remove scale, a cleaning solution is poured into both cavities of the heat exchanger. To increase the efficiency of the process, it is recommended to place the liquid-filled heat exchanger in a container in a water bath and maintain it at a temperature above 60 o C for at least 1 hour. Then the heat exchanger cavities are washed under a strong stream of water from the tap.
To fill all the cavities of the secondary DHW heat exchanger of a wall-mounted gas boiler, it will take approximately 0.25 liters cleaning solution.
The chemical reaction of scale salts with acid produces carbon dioxide. Therefore, the release of gas bubbles can be observed from the openings of the heat exchanger.
If the gas evolution stops, then the chemical reaction has stopped. This can happen in two cases, either there are no more scale salts in the heat exchanger, or there is not enough acid to continue the reaction with the scale remaining there. The acid concentration in the solution gradually decreases as it reacts with scale salts.
If there are doubts about completely descaling the heat exchanger, I recommend rinsing the heat exchanger with a strong stream of water and pouring a new fresh portion of acid solution into it. Repeat the entire cleaning process. If you see that gas bubbles have reappeared, then you didn’t do it in vain.
Forced circulation of solution in a heat exchanger removed from the boiler
And from the next video you will find out how to remove a bithermal heat exchanger using the Nova Florida boiler as an example.
In this option, the heat exchanger removed from the boiler is connected to a pumping unit, with the help of which The cleaning solution is forced to circulate through the heat exchanger channels. The bithermal heat exchanger has a complex channel configuration.
This cleaning method allows you to quickly and more efficiently remove significant scale deposits from the heat exchanger.
Descaling without removing the heat exchanger from the boiler or column
The following video shows how to assemble a simple device from available materials for cleaning the heat exchanger without removing it from the boiler.
I would like to draw your attention to the following:
- You can take any of the available pumps, including those from used equipment.
- Be sure to install a filter at the pump inlet or after the pump, at the water supply to the boiler. Otherwise, dirt from the container with the solution will go back into the boiler and clog the filter and flow sensor in the boiler.
- It is better to heat the solution to 60 degrees. To do this, you can even turn on the boiler for a short time to heat the hot water supply.
In this option, you should not change the direction of movement of the cleaning solution. It must coincide with the direction of water movement during boiler operation.
You should be more careful when choosing the composition and concentration of the solution to remove scale. Solutions can have a destructive effect on other parts of the boiler, including those made of different metals, plastic and rubber.
In private houses with a central water supply, water that has undergone disinfection and rough cleaning is used as a coolant for hot water supply and heating. This coolant contains large quantities various suspended substances, including Ca and Mg, which under the influence high temperatures, more than 65°C, due to a malfunction of the geyser modules, unsatisfactory water pressure, they form carbonate sediment (CaCO3, MgCO3). Such deposits are called scale.
Scale adheres firmly to metal surface inside the heat exchanger, pipeline, etc.
Low thermal conductivity of scale and good adhesion leads to:
- overheating of the tubes and plates of the heat exchanger, up to its damage;
- overconsumption of energy resources;
- reduction of water consumption due to overgrowing of internal pipeline channels and water heater elements;
- clogging of valves, taps and other system elements;
- reducing the thermal power of the device.
Over time, the outer part of the heat exchanger becomes covered with fuel combustion products. The formation of soot is promoted by the intense flame of a gas burner, poor draft in the chimney, unsatisfactory gas-to-air ratio, increased content of additional impurities in the fuel, and the ingress of contaminated condensate from the chimney. Soot affects heat exchange and leads to increased gas and water consumption.
Signs of heat exchanger contamination
To prevent premature failure of the water heater due to the listed symptoms, it is advisable to call specialists as soon as possible to diagnose and repair the malfunction. Since the heat exchanger is contaminated on the outside with soot, and on the inside with scale and patina (copper corrosion), we will consider the signs for each individual case.
The following indicators indirectly indicate the appearance of scale in the heat exchanger geyser and water heating system:
- Water consumption from a hot water tap is significantly lower than from a cold tap. To identify the true cause of the decrease in pressure, the condition of the shut-off valves is checked, since its breakdown can lead to a similar situation.
- The appliance is set to maximum power, but the water does not reach the set temperature. Such symptoms are possible when the pressure in the gas main. Therefore, before dismantling and cleaning the heat exchanger, the supply gas pressure should be examined. In the absence of a low pressure pressure gauge, you can navigate by the burner readings gas oven. The presence of a normal flame will indicate normal pressure in the system.
- The water heater burners begin to turn on and off frequently. But, such a malfunction can also occur if the gas valve or control module is unstable.
- There is noise inside the double-circuit boiler. It is worth considering that noise in the heat exchanger also occurs due to boiling water, or breakdown and clogging of the pump turbine. Boiling of the coolant is possible due to poor contact of the temperature sensors with the pipeline.
The listed signs indirectly indicate the formation of scale in the heat exchanger of the column, so first of all you need to check the components that affect the occurrence of the above signs.
External contamination of the heat exchanger is determined by opening the device housing. The radiator is considered dirty if it is more than 30% covered with black deposits.
Cleaning Frequency
The frequency of cleaning the heat exchanger depends on the frequency of use of the water heater, the pressure and hardness of the water, the serviceability of the components, the presence of a protective layer against scale, and the condition of the chimney. Under some operating conditions of the same model of a flow radiator, it is necessary to clean it after 6 months, and under other conditions – after 3 years.
Methods for cleaning the heat exchanger
Removal of scale and soot can be done mechanically or using special chemicals.
Mechanical cleaning
The cleaning process is carried out using a foam sponge, a brush with soft bristles, and a mini sink. high pressure. The most effective of the listed tools, allowing you to quickly remove plaque and destroyed layers of scale, is a mini high-pressure washer.
Before cleaning, for a high-quality reaction, it is advisable to apply a special liquid for removing carbon deposits to the radiator plates, or treat the surface detergent for dishes. You can combine two methods of removing dirt and pour descaling liquid into the coil. After 30 - 40 minutes, and with the combined method after 30 - 180 minutes (depending on the type of reagent used), thoroughly rinse the elements of the flow radiator with water under pressure.
Cleaning with chemical reagents
Dry cleaning can take place at a static or dynamic pace. When using the static method, the heat exchanger is removed from the water heater and filled with the active substance:
- Hydrochloric acid (H2SO4) with additives to prevent active reaction with metal (inhibitors). When acid comes into contact with a metal surface, the protective layer is damaged and the thickness of the coil wall becomes thinner, so inhibitors are added to it to prevent corrosive wear. After flushing the radiator, the spent acid residues from the coil must be neutralized with an alkaline solution, such as soda dissolved in water, before being poured into the sewer.
- Orthophosphoric acid (H3PO4). Neutral agent, reacts well with carbonates, does not harm the metal components of the system. An effective reagent is obtained by mixing H3PO4 and water in a ratio of 1/6.
- Aminosulfonic acid (NH3SO3) - an iron oxide remover. To prevent metal parts from being subject to premature wear when cleaning the boiler heat exchanger, a liquid consisting of corrosion inhibitors, water with a concentration of NH3SO3 in an amount of 2-3% is used.
- Citric (C6H8O7) or acetic (C2H4O2) acid. These substances are less dangerous to metal and humans than hydrochloric, orthophosphoric and aminosulfonic acid. But the decalcification reaction lasts several times longer than when treated with hydrochloric or phosphoric acid. If 30 - 40 minutes are enough to react with the same amount of H2SO4 scale, then for citric and acetic acid the time increases to 3 - 4 hours.
- Special liquid for descaling. Specialized stores sell certified substances, for example, Detex, Boiler Cleaner E, which easily deal with scale. After some concentrates, it is necessary to additionally treat the cavities with an acidity neutralizer, while others do not need to be treated with a neutralizer, since they are neutral to the components of the system. Service centers should use only certified fluids. Subject to this rule, the company is guaranteed to have protection from claims of the owner, whose heat exchanger, after carrying out chemical cleaning drip.
The dynamic method of removing carbonates is carried out with special boosters. A booster is a device designed to circulate scale-active liquid both through the heating system and through its individual components. The flushing liquid used is the same as for static cleaning.
Use of H2SO4 causes premature corrosion metal parts booster.
All events are held outdoors or in a well-ventilated area, using personal protection(glasses, rubber gloves) in clothing that covers parts of the body well to prevent acid and fumes from entering the human body. To improve the catalytic reaction and reduce processing time, the contacting liquid should be 50 - 60°C.
How to clean the heat exchanger of a geyser from scale
Let's take a closer look at how to clean the heat exchanger of a Termet TermaQ geyser. The presented heater model is equipped with a chimney with an outlet for condensate collection and inspection, and a semi-automatic burner ignition system.
You will need the following tools, equipment and materials:
- adjustable wrench;
- screwdriver set;
- stationery knife;
- container for heating the heat exchanger and for draining the spent solution;
- mini high pressure washer;
- vinegar solution;
- dishwashing detergent;
- baking soda;
- rubber, 3/4 inch gaskets;
- foam sponge;
- sandpaper.
Before the inspection, it is necessary to close the gas and cold water supply valve to the device. Unscrew the nuts with the feed and hotline and drain the water from the heater.
Heat exchanger cleaning sequence:
- Remove the water and gas flow control knobs.
- Remove the water heater cover.
- Using an adjustable wrench, unscrew the heat exchanger nuts. If they do not unscrew, apply WD 40 to the joint and wait 30 - 40 minutes and try again.
- Unscrew the front heat exchanger clamp, water temperature control sensor and housing strip.
- Remove the element to be dismantled from the device.
- Using a foam sponge, generously apply dishwashing detergent to the outside of the heat exchanger.
- After 30 - 40 minutes, carefully, so as not to damage the plates, thoroughly wash off the carbon deposits with a mini sink.
- Fill the container prepared for the heat exchanger with hot water (50 - 60°C).
- Place the heat exchanger in a container with hot water, and pour a solution of acetic acid into the coil.
- Maintain temperature 50 - 60°C.
- After three hours, drain the used liquid from the heat exchanger into a container for collecting the waste solution.
- Neutralize the acid with baking soda and pour the solution down the drain or onto the ground.
- Using a mini sink, wash the coil to remove any remaining scale and acid.
- scraper or sharp knife On the coil and pipes for connecting the heat exchanger, clean the contact areas of the sealing insert.
- Place the heat exchanger in place and secure it with straps.
- Sandpaper or stationery knife remove dirty, oxidized deposits from the junction of the control sensor housing and the coil. This operation can be performed before installing the heat exchanger in its original location.
To improve thermal conductivity, contacting surfaces can be degreased and thermal paste, for example KPT 8, can be applied to them.
- Fix the water control sensor on the coil with bolts.
- Connect the water heater to the water supply.
- Open the heater supply valve to fill the hot water circuit with water.
- Check the tightness of the mounted unit.
- Attach the housing in place, and install the handles on the water and gas regulators.
Check the system for leaks periodically, every 3-4 days.
Cleaning the gas burner of a water heater
A gas burner clogged with debris and soot contributes to the formation of soot on the plates and coil of the water heater.
To ensure a high-quality inspection of the heating unit, it is advisable to clean it gas burners. This operation can be performed either with improvised means (brush, rag, etc.) or with a mini high-pressure washer.
It is advisable to carry out the procedure when cleaning the gas water heater heat exchanger.
The procedure for conducting an inspection of the Termet TermaQ gas water heater
After removing the heat exchanger of the gas water heater, unscrew the fastenings of the nozzles.
Disconnect the wick, ignition electrode and thermocouple mounting strip from the injectors. Remove the gas burner block.
Rinse the dismantled unit under running water or pressure.
Washing gas water heater burners.
Dry the cleaned burners and reinstall them in reverse order.
Subject to availability the necessary tool, skills, cleaning the heat exchanger of a geyser goes quickly. Due to this, the service life of the water heater is significantly increased.
Heat exchangers and gas boilers are most susceptible to scale; hard water affects them more strongly than other water heating devices. The problem is becoming global, since in the case of a boiler it can be not just scale, but even lime stone. In addition to the walls, the pipes through which water is supplied and discharged are affected, which will significantly complicate the cleaning process.
Despite the fact that a gas boiler is a seasonal business, during its operation it performs a task every 24 hours, that is, the raid is continuously deposited. Therefore, at the end of each heating period, it is necessary to flush gas boilers from scale.
In order not to encounter the most unpleasant situations, we recommend that you familiarize yourself with further information and, armed with knowledge, prevent the breakdown of important equipment.
A gas boiler is a complex and expensive system. If using a kettle or pan it is easy to suspect formations that are forming, then inside such a device, and even more so in pipes, this is impossible. However, you should not think that if a problem is invisible, then it does not exist. Replacing the same kettle will be much cheaper than replacing one gas boiler.
They are used for space heating and water heating. This process usually involves fuel or electricity. Under pressure, steam is generated or water is heated, depending on the type of device.
What is scale? This is a solid sediment that consists of impurities found in the liquid. Mainly from salts, metal ions and other things. As mentioned earlier, the most dangerous thing is that the solid layer interferes not only with the operation of the boiler, but also with the passage of water through the pipes, since it simultaneously appears everywhere. If you do not clean, you may encounter unexpected troubles. To heat the water, the heat exchanger will require more time and resources. In order to start heating water, you need to heat up yourself, and when there is an additional mineral layer, this requires time and gas (electric) costs. With such expenses, operation will be too expensive.
In order not to fail, a gas boiler needs to heat up evenly and cool evenly. With scale this becomes impossible. Due to clogged pipes, the load on the pump increases, which leads to its breakdown.
Methods for descaling a gas boiler
There are several ways to descale a gas boiler. Firstly, this mechanical method, in which all formations are cleaned out manually or using a special mechanical tool. Secondly, - chemical method, affecting scale with acids.
Step by step instructions
If you chose the first cleaning option, then you need to stock up on a metal scraper and brush. The advantage of special devices is great opportunities, since there are various attachments that allow you to get into the most inaccessible areas. After this procedure, the gas boiler is washed running water, if necessary, it is cleaned again.
For the second option, you will need technical hydrochloric acid. A solution is made from it depending on the thickness of the scale. For every millimeter of scale you need a 1% solution. An important condition is that there should not be less than three percent and no more than ten percent.
Heating or boiling such liquid is strictly prohibited. It is necessary to follow all safety precautions and work in a well-ventilated area. To prevent the metal walls from being destroyed, a passivator is added to the solution (approximately 1/10 part). Needs to be upgraded active substance through a gas boiler. At this time, there will be a lot of hissing and gas release. When these signs stop, you need to add water and flush everything down the drain. Complete cleaning by rinsing clean water. This is a very dangerous method that is better to entrust to a specialist or do it yourself under the supervision of an experienced chemist.
Prevention measures
Removing scale from a gas boiler is not the easiest task. However, it should not be put off until later and regularity should not be neglected.
If you decide to do this yourself, you should be aware of the consequences. Using excess force when mechanical cleaning You risk snagging or chipping the metal. But with chemical components, and especially with acids, everything is much more serious. The slightest error in concentration or leaving the solution for more than the prescribed time can cause significant damage. Repair, and even more so replacement, will be a big blow to your pocket. To prevent this, we recommend purchasing a special filter that purifies and softens water, creating favorable conditions for operation of heating devices.