Descaling in a gas boiler. Preventive measures are beneficial. What is a heat exchanger

Flushing the gas boiler heat exchanger increases the efficiency of the heater and helps save on heating bills. After all, the heat exchanger “clogged” with scale “captures” far from all the “calories” of the gas burning in the boiler furnace. As a result, some of the fuel is wasted.

In turn, a "clean" heat exchanger maximizes efficiency (the ratio of energy consumed and delivered) to the maximum, increasing the efficiency of the system and reducing the cost of consumed gas.

Therefore, in this article we will consider the process of "cleaning" heat exchangers. Indeed, given the current high cost of gas, this information will be of interest to all owners of boilers and columns.

When should the heat exchanger be cleaned?

In addition, the frequency of cleaning also depends on the structural material from which the heating system wiring fittings were made. After all, rusting steel pipes The heat exchanger will be “clogged” with flakes of iron oxide in a couple of seasons, and completely inert polymer reinforcement is devoid of such a disadvantage in principle.

Tip: if you want to reduce the frequency of cleaning, fill the system with rainwater. It will cost less than distilled liquid and reduce the risk of scale formation. Also, when wiring the system, use plastic pipes. They will save you from rust that clogs the heat exchanger in a couple of seasons.

How are gas boiler heat exchangers cleaned?

Scale, rust and other components of the plug that clogs the tube section of the heat exchanger are brought by water. Therefore, in the process of cleaning, we must start this process in reverse side- flush the heat exchanger with the same water, which will wash out the plug in the pipes and remove particles of "dirt" from the boiler.

However, the lime plug accumulates on the inner walls of the heat exchanger tube for several years, and we would like to complete the cleaning process in a couple of hours. Therefore, ordinary water needs "helpers" - abrasive particles and chemicals that accelerate the "peeling" of plaque.

As a result, the process of cleaning the heat exchanger is as follows:

• You supply water flavored with "assistants" into the pressure pipe of the boiler. Moreover, the flow must be directed precisely from the side of the pressure fitting: after all, it is located at the top point of the heat exchanger.
• After some time, and sometimes immediately, you collect water and flakes of rust and scale at the “return” fitting.

How to flush the heat exchanger of a gas boiler?

• Chemical flush. It is implemented by introducing into the heat exchanger weak solutions of acids that destroy calcium and magnesium salts. In addition, chemical washing is able to cope with rust. Reagents can be poured into the boiler through the pressure fitting and drained from the "return" outlet after some time. Abundant washing in this case is required. Remaining reagents can “burn through” heat exchanger pipes or wiring.
• Hydroabrasive washing. It is implemented in the process of circulation through the heat exchanger of a concentrated suspension of abrasive particles, grinding inner surface pipes. Abrasive slurry is fed into the pressure nozzle and exits the "return" outlet without delay. Moreover, this cycle is repeated many times. After hydroabrasive cleaning, the heat exchanger will have to be slightly rinsed.
• Hydraulic flush. It is implemented using special nozzles introduced into the heat exchanger tube. These nozzles expel streams of water supplied under strong pressure. These streams wash out scale and rust, destroying plugs and sediment. The nozzle is introduced from the side of the pressure pipe, and the return pipe is connected with a hose to the sewer. Additional flushing is not required in this case.

Tip: Do not attempt to flush the boiler yourself. Each cleaning method involves the use of a special tool and reagents. Without certain skills and practice, at best, you will “fail” this business, and at worst, damage the heat exchanger.

How to flush the heat exchanger of a gas boiler?

It all depends on the washing method. The chemical option involves the use of hydrochloric and sulfuric acids as reagents. IN last resort, you can use nitrogen or phosphoric acid. Hydroabrasive cleaning involves the use as a reagent of concentrated suspensions based on abrasive materials - sand, corundum and others.

In addition, in the process of abrasive and dry cleaning, we will need a set of containers and pressure equipment to ensure the circulation of reagents through the insides of the heat exchanger.

Usually in the role of such a kit they use turnkey solution– booster for flushing the heat exchanger. It consists of a reagent tank and a pressure unit - a pump. Moreover, it is better to use drainage equipment as a pump, capable of pumping a contaminated medium through the working chamber.

A tank with a reagent is connected to the intake pipe of the pump, and the pressure pipe of the unit is connected to the upper fitting of the boiler. In turn, the lower fitting of the heater is connected to the tank by installing a simple filter at the junction point.

The booster pump ensures the circulation of reagents, and the filter “catches” rust flakes and the remains of destroyed scale.

Moreover, cleaning with a booster does not imply complete dismantling boiler. To start flushing, you just need to disconnect the boiler from the wiring and connect its pipes to the corresponding “connectors” of the booster.

on which the efficiency of its work depends.

Over time, especially if the water in the boiler is hard, it becomes clogged and becomes unusable.

How to flush the heat exchanger of a gas boiler, can I do it myself or is it better to contact the service?

When is it worth saving, and when not? In what cases is intervention required, and when is it worth looking for the cause somewhere else?

During combustion, a layer of soot is inevitably formed over time on the heat exchanger, furnace walls and nozzles.

Nozzles are parts of a gas boiler on which a flame forms and through which gas is supplied for combustion.

Before flushing the heat exchanger of a gas boiler, it is necessary to clean it of soot.

Soot is formed when low-quality gas is used. For example, in those designed to run on natural gas, propane-butane gas, another gas, is used.

Usually, services that offer to flush the gas boiler heat exchanger at home offer flushing without removing the heat exchanger. To do this, they have a special device that allows you to connect and pass a special cleaning solution through it.

As a result, after a while, from half an hour to two hours, the boiler is cleaned of scale.

In principle, the device is quite simple and consists of a small circulation pump and a pipe system. If you have all the necessary parts, you can assemble it yourself. However, if you have to buy something, especially a pump, the idea will not pay off.

The fact is that the cleaning procedure itself costs from 500 to 1500 rubles in different cities.

Cleaning is required every 2-3 years.

The purchase of a pump will cost about 3,000 rubles, and it will pay off in 2-6 cleanings and 4-18 years.

Therefore, it makes sense to contact the service departments.

The washing solution consists of reagents that dissolve calcium salts.

The advantages of cleaning the heat exchanger without removing it are that you do not need to waste time removing it, it is often impossible to remove this part, and this method is the only possible one.

Disadvantages - if the pipes are connected to the boiler with a hard connection, or if they are stainless steel, which were assembled using welding inserts, then it is often impossible to remove them and attach the cleaning pipes at all.

How to remove the heat exchanger, disassemble and assemble it, and put it back in place

This procedure may be required before cleaning the boiler from soot, or before cleaning the heat exchanger of a gas boiler at home with removal.

If the boiler is connected to the pipelines "tightly", then this method is the only possible one without cutting the pipes. Read the instructions before removing the heat exchanger.

In most cases, it is necessary to remove the protective covers and then disconnect the heat exchanger from the nozzles by loosening the latches.

Different boilers may have different design, so the heat exchanger must be removed carefully, carefully fixing the whole process so that you can then put it back.

In some cases, it is not necessary to remove the nuts, and the heat exchanger has a collapsible design with latches or generally non-collapsible. In the latter case, it can only be cleaned with special device passing a cleaning solution through it.

After cleaning, the heat exchanger must be replaced. The instructions for the heat exchanger and the previously recorded removal process will help in this. You can fix it on paper with text, with the help of drawings, photographs or on video:

According to an old folk tradition, periodic cleaning of a gas boiler with flushing of heat exchangers is carried out by the user in case of emergency, when the water is not heated at all or something has broken. On call, a master comes and repairs the unit for your money, cleans and sets everything up. Moreover, the design of most gas boilers used in private houses and apartments allows them to be periodically cleaned with their own hands.

When to clean up

There are 3 options for the development of events:

1. Preventive cleaning of the boiler is done by the homeowner himself once every 2 years at the lowest cost.
2. The procedure is performed as the heat exchangers are contaminated with soot and scale, which reduces the efficiency of heating and heating water for the needs of hot water supply. In this situation, you can still clean the boiler yourself, although the call of the master is also not excluded.
3. The heat generator has stopped due to a breakdown, which often happens during heating season. The malfunction is eliminated by the called specialist, who also cleans the heat exchanger from soot.

The last 2 scenarios are clearly unattractive for the owners of the house, since they are associated with inconvenience and financial costs. You can not do without a master even if a condensing boiler with a burner and a specially designed heat exchanger is used for heating. Climbing there on your own is not recommended, unless you are well versed in heating equipment of this kind.

Conclusion: preventive cleaning and flushing of the heat exchanger is carried out quite quickly and does not require expenses, which is why it is the best solution.

How to clean the heat exchanger of a floor gas boiler

To disassemble the heating unit at home, you do not need any special tools, a simple set with screwdrivers, keys and pliers is enough. Preventive cleaning of the heat exchanger from soot and scale is carried out in the off-season, when it is turned off. Having previously shut off the gas supply, we begin disassembling the boiler by removing the burner in the following sequence:

1. Disconnect all wires from the gas valve.
2. Remove from the combustion chamber the thermocouple connected to gas valve capillary tube.
3. Disconnect the gas supply pipe.
4. Unscrew the 4 nuts (or bolts) holding the stove with the burner. Pull the assembly outward, as shown in the photo:

The gas boiler burner is cleaned without further disassembly using an old toothbrush. The igniter, piezoelectric ignition device and flame control sensor (if any) should also be cleaned of soot. Now you need to get to the heat exchanger, for which you need to remove top cover boiler, disconnect the draft sensor and the chimney. In the opening that opens, you will see a heater covering the chimney casing. Carefully remove the insulation, and then unscrew the screws securing the casing and remove it. Below it is a heat exchanger, from which steel turbulators must be removed, as shown in the photo:

There is no point in talking a lot about how to clean the turbulators, this is done with an ordinary brush with a metal bristle. But cleaning the floor boiler heat exchanger is best done with the help of simple hand-made tools according to the size of the fire tubes. If they have a rectangular cross section, then it is necessary to make from thin metal planks a convenient flat spatula and a small scraper in the form of a scoop.

For round flame tubes, the same instruments are made slightly curved. First, the walls of the pipes should be cleaned with a scoop, after which the soot remaining in the corners should be removed with a spatula.

At the end of work, all surfaces of the heat exchanger can be covered with a brush screwed to a long handle. The last step is to remove soot from the bottom, where it was poured when cleaning the smoke pipes. This is what a clean heat exchanger of a heating unit looks like:

You can take a closer look at how to clean a gas boiler at home in the video:

Note. In the presented video, the master violated the sequence of actions. First, he cleans the heat exchanger, and then removes the burner, covered with soot. It’s wrong to do this, first you need to remove the burner, and only then clean off the carbon deposits from the walls of the flame tubes.

We clean the wall-mounted heat generator from soot

Getting to the main heat exchanger of most wall-mounted gas boilers is quite simple. The work algorithm is as follows:

1. Turn off the gas supply by shutting off the corresponding valve.
2. Remove the front panel of the unit.
3. Unscrew and remove the front cover covering the combustion chamber.

So that the soot to be removed does not fall into the holes of the gas burner and you do not have to think about how to remove the burner in order to clean it, you need to cover the nozzles with a sheet thick paper or cardboard. Then, with an old toothbrush, clean the fins of the heat exchange unit from carbon deposits. If the stuck layer does not lend itself, then you can use a brush with a soft metal bristle.

At the end, sweep the unit from the inside with a brush and carefully remove a sheet of paper with soot. How to maintain a wall-mounted boiler is shown in detail in the video:

Rinsing and descaling

The procedure for removing scale from the internal heat exchange surfaces of gas boilers is carried out in two ways: with and without removing the heat exchanger. If you intend to regularly clean and rinse your heat generator, then it is more expedient to choose the second option. Each time dismantling the boiler to remove the heat exchanger is a rather troublesome business. Yes, and the designs of heaters are different, some need to be laid out almost by cogs.

To flush the boiler without disassembly, you will have to make a flushing unit with your own hands - a booster. It is a container of 15-20 liters, filled with flushing solution, with connected hoses. Their ends are connected to the supply and return pipes of the heat generator and turn it on for heating. The circulation is provided by a separate pump, the same as in the heating system. It is even better when a reversible pump is found on the farm in order to periodically change the direction of the fluid flow.

Advice. On the hose that supplies the solution from the booster to the heating unit, put a strainer so that the scale does not circulate in a circle. It is possible that during flushing it will have to be cleaned several times.

Before flushing the main heat exchanger of a gas boiler, the following operations must be performed:

• reset the pressure in the network to zero using special valve(these are in some boilers) or on the nearest radiator;
• isolate the heater from the system and empty it;
• check if your unit model has a built-in sump, remove and clean it.

A few words about how you can flush the heat exchanger of a gas boiler. most popular folk remedy, safe for all elements of the heat generator, is considered a solution of citric acid and vinegar. According to user reviews of a well-known forum, 9% vinegar or citric acid, dissolved at the rate of 20 g per 1 liter of water, works well. If necessary, the concentration can be increased.

In addition, there are many factory-made products for chemical cleaning of heat exchangers (for example, Antinakipin). The washing time is indicated on the product packaging, and when working with citric acid, the duration of the process depends on the degree of contamination and can take from 1 to 3 hours.

Advice. If a reversible pump is not available, then during operation, periodically change the hoses in places, starting the fluid flow in the opposite direction. In case of reverse flow, the heating must be turned off.

After flushing, fill the tank with ordinary purified water and rinse the unit from chemicals and dirt residues, clean the sump again.

How to flush the heat exchanger of a double-circuit boiler

The method of descaling the DHW path depends on the type of heat exchanger installed in your heat generator. There are only two of them:

• bithermic, it combines the heating of the coolant and water for hot water supply;
• secondary heater from of stainless steel.

It is better to clean the units of the first type with the help of a booster, since it can be quite difficult to remove such a unit. Hoses leading from the tank are connected instead of supply cold water and exit hot, after which it starts circulation pump and the boiler itself. The heating temperature should be limited to 50-55 degrees.

If there is a secondary heat exchanger in the double-circuit boiler, the latter can in most cases be removed. To do this, the front panel is removed, and then the control unit is unscrewed and moved aside. The secondary heat exchanger is located at the bottom and is fixed with 2 bolts. After removing it, it is immersed in a saucepan with citric acid dissolved in water and boiled for gas stove which is detailed in the video:

Conclusion

To clean the parts of the gas boiler from soot, it is not necessary to call the master; if desired, this procedure is done by hand without any problems. It is more difficult with flushing heat exchangers, here you need to have some skills and confidence that you will succeed. If you opened the panel of the heating unit and lost confidence in the success of the event, then for the first time it is better to call a specialist and carefully follow the procedure. Then next time you can do it yourself.

To save effective work gas boiler, it is necessary to take timely measures to care for it. The most difficult and time-consuming is flushing the heat exchanger of the unit. During prolonged operation, especially if there is no water filter, lime deposits will accumulate in the heat exchanger. To prevent this problem from putting the gas boiler out of action, it is necessary to periodically clean the circuit. Therefore, many users of the units are interested in how to clean the heat exchanger of a gas boiler.

The heat exchanger of a gas boiler is a curved pipe made of metal or cast iron. It's heated by the flame gas burner, and then transfers heat to the heat transfer fluid, which moves throughout the heating system. If the heat exchanger is clean, then it effectively transfers heat. When salt deposits accumulate in it, its thermal conductivity decreases. Then the gas boiler has to heat the coolant longer, which entails an increase in fuel and electricity consumption.

If the element is heavily contaminated, in order to maintain the desired temperature, it needs to be in the maximum heated state for a long time - this leads to overheating of the heat exchanger and its failure.

Deposits and scale also prevent the coolant from moving along the circuit. As a result, the load on the circulation pump increases.

Thus, a contaminated heat exchanger threatens to fail not only the element itself, but also other important nodes unit. To prevent damage, the boiler should be cleaned regularly.