How to solder a gas water heater. Heat exchanger for a geyser: why a radiator is needed, how to solder it and clean it. Which column has a good heat exchanger?

A heat exchanger is one of the main devices in a gas heating apparatus, which is responsible for heating the coolant. In a gas water heater, the heat exchanger has a solid surface through which heat is transferred to the coolant. Due to the influence of various external factors, fistulas and ruptures may appear in the walls of the coolant, and the gas water heater may begin to leak. You can fix the problem yourself. How - read below.

A geyser is an affordable and reliable water heating equipment. But, due to poor quality water and gas, the service life of a gas water heater can be reduced significantly. To avoid replacing equipment every few years, you should understand how to repair it. So, most often, column leaks and insufficient heating of the coolant are associated with malfunctions of the heat exchanger. Problems can usually be fixed in two ways: by cleaning or soldering the heat exchange device.

At the same time, in order to avoid situations hazardous to health and life, repair work should be carried out:

• After stopping the supply of water (or other coolant) and gas;
• On an empty device (you must first drain the water from the gas water heater or remove any other coolant);
• Wear protective gloves, glasses, clothing (if we are talking about soldering).

If to execute repair work you decide to call a specialist, choose only certified professionals with good reviews. At the same time, it will not be superfluous to independently understand the structure of the gas water heater and how to repair the equipment. After all, you may come across an unscrupulous worker who, seeing your incompetence, will “find” non-existent faults in order to obtain maximum financial gain.

Soldering the geyser heat exchanger

Soldering the heat exchange device gas equipment performed when the element is depressurized. Most often, the appearance of fistulas in copper heat exchangers is associated with poor-quality, hard water. So, in most cities today, water is disinfected with chlorine. When heated, the chlorine in the water reacts with copper (the heat exchanger material), forming copper chloride. As a result, the walls and tubes of the heat exchanger begin to collapse from the inside. Frozen water in the system and the presence of stray currents can also lead to rupture of the walls of the heat exchanger.

Soldering the heat exchanger can be done in three ways:

• using a soldering iron with a power of at least 100 W;
• using a burner with a gas cylinder;
• cold welding.

Before applying solder, the surface of the radiator should be cleaned. Not only gaping fistulas should be treated, but also greenish spots on the surface of the heat exchanger, which indicate thinning of the metal.

In order for the solder to flow well over the metal, it is better to use copper flux paste for soldering.

You can replace it with more affordable rosin. On average, good soldering lasts six months. Grounding the column can reduce the likelihood of new leaks forming. You can extend the life of the heat exchanger by installing a filter at the system inlet that purifies and softens the water.

How to remove a heat exchanger from a gas water heater

In some cases, for example, when the fistula or rupture is on the wall of the heat exchanger, which is adjacent to the base of the gas equipment, the radiator must be removed for repair. In addition, dismantling the heat exchange device may be necessary if you decide to clean it.

To remove the heat exchanger from gas water heater necessary:

1. Turn off the water and gas supply to the gas water heater;
2. Remove the switch handle and casing from the device by unscrewing the connecting screws using a Phillips screwdriver;
3. Disconnect the chimney pipe;
4. Remove the overheating sensor from the upper metal element of the column;
5. Drill out the rivets holding the upper metal element from dismantling;
6. Remove the top metal structure moving your hand up;
7. Using a wrench, unscrew the nuts from the pipes to which the heat exchanger is attached;
8. Remove the heat exchanger upwards.

If, after dismantling the device, you find that it cannot be repaired (for example, the heat exchanger has burned out), then it will have to be replaced with a new one. At the same time, the issue of choice should be approached carefully. Often, heat exchangers in stores are recycled: after replacing the elements under warranty, the manufacturer repairs the failed heat exchange device and sends it for sale. Pay attention to the weight of the heat exchanger: sometimes, in order to reduce the cost of producing a part, the manufacturer deliberately makes the walls of the element thinner. This significantly affects the service life of the heat exchanger. How much does it weigh quality device? On average, at least 3 kg.

How to clean a geyser radiator

Among the regular gas maintenance activities water heating equipment Cleaning the heat exchange device is important. Cleaning should be done at least once a year. If your region has hard water with various impurities, then the event can be held more often. In addition, cleaning is the first thing that can be done if the column begins to heat water worse for no apparent reason.

The best substance for cleaning the heat exchanger at home is considered to be citric acid.

Citric acid is available to everyone, effective and absolutely safe for metal. At the same time, the product does not emit carcinogenic substances or unpleasant odor.

In order to clean the radiator with a “lemon” you need to:

1. Dissolve 100 grams of the substance in a liter of warm water;
2. Pour the resulting solution into the heat exchanger;
3. Place the part in a container with solution;
4. Wait 15-20 minutes;
5. Rinse the radiator with running water;
6. Wait for the part to dry.

You can use vinegar essence to clean the radiator. At the same time, the cleaning algorithm should remain unchanged. You can rid the radiator of scale using special means(for example, anti-scale agent SK-110A).

How a heat exchanger for a geyser works (video)

The most efficient, affordable and economical household water heater today is a gas water heater. The equipment consists of a heat exchanger, igniter and main burner. The copper heat exchanger is most susceptible to wear: under the influence of hard water, the tubes of the element become clogged and its walls are corroded. But don’t worry: you can repair equipment yourself. And the instructions and recommendations presented above will help you with this!

The main part of a flow-through heater is the heat exchanger, which can leak over time. You have a choice: perform the repair yourself or contact a workshop. We'll tell you how to solder geyser with your own hands.

Causes of leakage

A common cause of leaks is a brass or copper radiator. Since manufacturers make some elements not from pure copper, but with the addition of impurities, these places oxidize faster. As a result, the heat exchanger corrodes or burns out.

An additional reason for the breakdown is the method of water disinfection in the region. Chlorine dioxide is most often used for these purposes. When heated in the radiator tubes, chlorine reacts with copper, which contributes to the destruction and formation of fistulas. It has been proven that in places with disinfection using ozonation, such problems with geysers do not arise.

Preparation for soldering

Prepare the tools you will need for your work:

• Soldering iron (at least 100 W).
• Metal brush or fine sandpaper.
• Solder. It is recommended to take an alloy of tin and lead.
• Flux. You can take rosin or small crumbs of aspirin tablets. The latter should be sprinkled onto the heated place so that it spreads.

Now you need to prepare the column. To determine the location of the leak, do not rush to turn off the water. Do this:

• Remove the casing from the device (you may need to unscrew the bolts).
• Turn on the water supply and inspect the heat exchanger for leaks.
• If you need to weld a copper tube on a bend in an accessible place, you do not have to remove the column.
• If the fistula is located in a hard-to-reach place, you need to dismantle the body and disassemble it.
• Turn off the gas supply.
• Drain the water. To do this, open the hot stream and remove the nut from the cold pipe.
• IN latest models There is a plug at the bottom. Place the container and open the cap. The water will drain on its own.

Important! Before starting repairs, the radiator must be completely dried with a compressor or vacuum cleaner. Otherwise, moisture will not allow the fistula to heal.

Now use sandpaper or a brush to clean the damaged area. Often in such places a green spot is visible. Do not use too much force to avoid damaging the tube further. Finally, wipe the stripped part with a degreaser.

Welding methods

We have already written how you can solder a heat exchanger. But there can be several welding methods.

Soldering iron

The method requires the presence of a powerful tool (at least 100-110 W). Also prepare solder and flux. Sprinkle the damaged area with flux and place solder on top using a soldering iron. Make sure it spreads evenly and covers the hole. Continue building until the layer reaches 2-3 mm.

After such repairs, the fistula will not manifest itself.

Gas-burner

This method is suitable for a thick-walled radiator that has high thermal conductivity. Connect the burner to gas cylinder, adjust the flame to a low level so as not to damage the walls of the heat exchanger.

The damaged area must be warmed well to remove any remaining water. Soldering is carried out with solder, after which the remaining flux is carefully removed. It contains acid, which can cause the tube to break down.

The video shows in detail how to solder correctly:

Cold welding

For these purposes you need to buy high-quality welding. Since the material will come into contact with water, it must have moisture-resistant properties.

• Wear gloves.
• Knead the weld until it becomes soft and pliable.
• Apply material to the leak area. Wait until it hardens.

Use a piece of copper pipe as the soldering material.

Upon completion of work, check all parts of the structure. Wherever green spots are visible, fistulas will soon appear. Therefore, it is better to immediately clean and solder the micro-holes so as not to repeat disassembly.

After connection, do not immediately put on the cover. Check the quality of the work performed using pressure from the water supply.

As was noted by users who independently carried out similar repairs, some speakers are equipped with already sealed heat exchangers at the factory. Faulty parts are repaired, the fistulas are soldered and reinstalled into the columns for sale. Therefore, be careful when purchasing equipment.

When you purchase a replacement radiator separately, inspect it for solder joints. If such a place is found, refuse to purchase. In case of replacement under warranty, keep the quality of the parts under control. They must be new, not used.

To avoid frequent repairs, opt for high-quality equipment from the manufacturer "", "", "". But in “” devices radiators made of very thin material are installed.

Modern house located in a remote locality or in the country, it is impossible to imagine without a gas water heater, because it serves as the main heating device for water. But if you begin to notice that the water does not want to heat up, then it is quite possible that the heat exchanger for the gas water heater is clogged. Find out how to clean it and what it actually is in this article.

Important! I would like to warn you right away that the article is about cleaning instantaneous water heaters from scale. We do not recommend interfering with the operation of the gas part of the water heater. The gas water heater should be handled by gas workers. Otherwise, even the smallest mistake can cause very big troubles.

Gas water heater device

Over time, salt solid deposits, otherwise called “scale,” accumulate on the heat exchanger for a gas water heater. In order to eliminate scale from a gas water heater, you must first understand the design of the heating device itself.

As a rule, a geyser is a metal cabinet to which two pipes are attached - one of them supplies cold water, and the second is gas.

The following elements are hidden inside such a cabinet:

• heat exchanger;
• main burner;
• igniter

Operating principle

As soon as you open the tap hot water, the ignition inside the column is automatically triggered. As a result, the pilot burner lights up, but it already ignites the main burner, with the help of which the process of heating the cold water inside the heat exchanger to the required temperature occurs.

By its design, the heat exchanger has the shape of a spiral. When the gas burns, a very high temperature is created, due to which the water quickly heats up and is immediately supplied to the collapsible taps. All natural gas combustion products pass through the outlet in the chimney pipe, and then out into the street.

All modern models of geysers are manufactured with various types of ignition - electric, manual and piezo ignition.

Important! Manual method, when fire appears by bringing a lit match to the igniter itself, is now used quite rarely. As a rule, people purchase models that do not require human intervention in the ignition process itself.

What causes the heat exchanger to become clogged with scale?

The most common malfunction of all gas flow heaters and geysers, the water heater is considered to be clogged with scale that has accumulated in the heat exchanger.

How to understand whether the heat exchanger in a gas water heater needs to be cleaned or not, and what causes it to clog. In the overgrowth of pipes instantaneous water heater As a rule, you yourself are to blame for scale build-up, and only sometimes hard water is to blame.

Reason 1

Why exactly you, because everyone around you is doing nothing but scolding the water? The thing is that scale begins to be deposited when the water temperature is above 80 degrees. Well, to be precise, at a temperature of 78 degrees, deposits have not yet formed, but at 82, intensive scale deposition begins.

Important! Why do you need this temperature?

• in order to take a bath, you do not need a temperature above 42 degrees;
• to eliminate fats - 45 degrees is enough; products for eliminating fat fight it even in cold water;
• To wash clothes, you don’t need more than 60 degrees, but now, as a rule, washing machines are used.

Draw your own conclusions.

Reason 2

Almost everyone leaves the column running on the igniter. Undoubtedly, this is quite convenient - there is no need to light it and then adjust it every time. The flame on the igniter is quite small, but if you drilled it to be safe, then only an hour is enough for the temperature in the heat exchanger to rise to 90 degrees. Here comes the scale!

Reason 3

And the third mistake is the operation of the column with very low water flow. Of course, an instantaneous water heater is unlikely to operate normally at low pressure.

Signs of the need to clean the geyser heat exchanger

Well, now, in case a problem has already occurred, let’s get down to cleaning the heat exchanger. You can understand that your geyser heat exchanger is already clogged by the following signs:

• low pressure hot water in the tap with good pressure cold water;
• The column either does not turn on at all, or turns on and immediately turns off again.

Important! The tap at the entrance to the column itself may also break, so check it first, and only then disassemble the column.

How to properly disassemble the column heat exchanger. What tools are needed for the job?

It is not worth describing absolutely the entire disassembly process. The main thing is that you must make sure that you have necessary tools. The minimum set is:

• Bako wrench or pipe wrench No. 1.
• Adjustable wrench.
• Screwdrivers - flat and Phillips, minimum No. 5.
• Set of paronite gaskets, spare.
• You will also need 60 cm of rubber hose along with a metal clamp.
• In advance, purchase “Antiscale” at the hardware store, which is sold in the form of a dry powder and then diluted with ordinary hot water.

Important! If you are lucky and you find Anti-Scalp in a plastic bottle there, it is better to take 2 pieces so that it is enough for 2 times.

Let's start disassembling:

1. First, remove all fittings from the boiler.
2. After this, remove the cover.
3. The casing has been removed, now you must decide on the water supply pipes so as not to accidentally touch the gas.

Flushing the column from unwanted scale

After you have removed the casing from the column:

1. Shut off the water supply at the entrance itself and open any of the hot water taps closer to the column.
2. Then unscrew the supply tube from the heat exchanger of the instantaneous water heater and move it slightly to the side. A copper heat exchanger and tube will allow you to do this without much difficulty.
3. As soon as you can unscrew the nut from the heating element, water will begin to leave the heat exchanger of the geyser - the tap is open, drain just a little water, about a liter.

1. Place the hose onto the inlet of your heat exchanger.
2. Raise it above the column.
3. Insert a funnel into the hose and pour in the prepared solution in a thin stream.

Important! Be sure to pour slowly, otherwise a reaction may occur and the solution will splash back out. The solution contains hydrochloric acid, which can cause burns. Take special care of your eyes.

1. The Antiscale solution must remain in the heat exchanger for several hours.
2. If you did not turn off the gas, you can heat the solution on the already burning igniter. The reaction will go much faster, which means it will take less time.
3. Place a plastic bucket or basin under the tap and turn on the water supply to the tap. Just a little bit.
4. Pay attention to what comes out of your hose:
   • If there is a lot of dirt, and the pressure after washing is good enough, then everything went very well.
   • If not, repeat the entire washing process again, but using Antiscale, you are unlikely to have to do this.

Important! If you could not find anti-scale agent, you can use a 100 g package citric acid, having previously dissolved it in 500 ml of water.

Warranty period (three years) NEVA LUX-5013 worked flawlessly, and in the fourth year of operation water began to drip from it. The hope that one of the gaskets had worn out was not justified. When the casing was removed from the gas water heater, a fistula was discovered in the heat exchanger, from which water was gushing.

After discovering the fistula, the first desire was to replace the geyser heat exchanger with a new one, but when I found out that its cost was 1/3 of the cost of a new column, I decided to try to repair the geyser heat exchanger myself, soldering it with solder using a soldering iron. I reasoned as follows: water flows through the heat exchanger tube, the temperature of which, when heated, cannot exceed 100˚C. The melting point of solder, depending on the brand, is about 200˚C. Consequently, the solder will not melt and the soldering will seal the leak reliably. The repair of the geyser heat exchanger was successful.

Communication with sellers of spare parts for geysers and friends identified the existing problem of water leakage in heat exchangers, both in gas water heaters from domestic and foreign manufacturers. As it turned out, the service life of geyser heat exchangers is mainly determined by the method of water disinfection during purification in the city water supply system.

Currently for disinfection tap water Chlorine or its dioxide is mainly used. Water containing chlorine, passing through the copper tube of the heat exchanger, heats up during operation of the gas water heater, and, as is known from chemistry, when heated, chlorine begins to react with copper, forming copper chloride. Thus, the tube is destroyed from the inside, which leads to the appearance of fistulas. In cities where water disinfection at treatment stations is carried out by ozonation, fistulas practically do not appear in the heat exchangers of flow-through gas and electric water heaters.

It is also worth noting that currently manufacturers have begun to install copper tubes with thinner walls and made from lower quality copper into heat exchangers. This is also one of the factors that reduces the service life of heat exchangers.

if the fistula is located in a place accessible for soldering

Before starting soldering, it is necessary to drain the water from the heat exchanger, otherwise the water will remove heat and it will be impossible to warm up the soldering area to the required temperature. To do this, open the hot water tap in the sink or sink and unscrew the union nut from the cold water supply pipe of the geyser. Since the column is located at a level higher than the tap, most of the water will drain, but not all. I use a blower to remove residue. This can be done with a compressor, a vacuum cleaner or your mouth. When blowing with your mouth, you can use a flexible hose from a shower head. One of the union nuts of the flexible hose is screwed through the gasket onto the thread of the water supply tube of the heat exchanger, and through the second end of the flexible hose the heat exchanger tube is blown through the mouth. The remaining water is drained through the tap, and you can begin repairing the heat exchanger.

The soldering itself is not difficult. If you do not have experience working with a soldering iron, you can familiarize yourself with the soldering technology on the website page “How to solder with a soldering iron”. Using fine sandpaper, clean the location of the fistula from oxides. As a rule, in this place the copper oxidizes and a greenish stain forms (clearly visible in the photo above). After cleaning, wipe the area with a cloth soaked in solvent to remove grease and dust. Tin with any solder, for example POS-61, (melting point not lower than 180°C) with a soldering iron with a power of at least 100 W.

Rosin can be used as a flux; the kind that is used to rub violin bows is also suitable. If you don’t have rosin, you can successfully use aspirin tablets (sold in pharmacies in the form of tablets called “acetylsalicylic acid”). It’s a wonderful flux, I use it all the time in cases where it’s impossible to clean. For example, when tinning stranded wires. You paint the tablet and sprinkle the tinning area with small crumbs, or rub the tablet over the heated surface. If, during tinning, the solder does not spread, but lies in a loose layer, it means that the soldering area is not heated sufficiently. In this case, you can additionally heat it with another 40 W soldering iron, hair dryer or iron, placing it next to the soldering area.

When the solder has evenly covered the required surface with a thin layer, you need to build it up to a thickness of 1-2 mm. The fistula on the heat exchanger has been eliminated and will never appear again.

Now carefully inspect the geyser heat exchanger tube along its entire length. If you find a green spot, it means that in this place there is most likely a microhole that allows water to pass through. You need to clean the tube with fine sandpaper until it shines and see if there is a small black dot. If there is one, then it should definitely be tinned and soldered. Otherwise, in a couple of months you will have to do repairs again.

How to solder a geyser radiator,
if the fistula is in a place inaccessible for soldering

If the location of the water leak occurs on the wall of the heat exchanger adjacent to the base of the gas water heater, then repairing the heat exchanger by soldering on site is impossible, and it must be removed from the gas water heater. The designers of NEVA LUX-5013 did their best. To remove the heat exchanger for repairs, you need to disassemble almost the entire gas water heater and, most unpleasantly, disconnect the gas pipe. I didn’t want to mess with gas pipes, as it’s dangerous.

The removal of the heat exchanger for repair was hampered by an umbrella for removing gas combustion products, secured with four aluminum rivets to the base of the gas water heater. I had to drill out these rivets with an electric drill, remove the umbrella, and only then did it become possible to remove the heat exchanger. During assembly, instead of rivets, the umbrella was secured to the base with two M4 screws. If the wall does not interfere, you can secure the umbrella with self-tapping screws.

Next, the repair of the gas water heater was carried out using the technology described above. In two last year I had to repair the heat exchanger, soldering the fistulas, five times. The last time, water began to leak from the side adjacent to the wall of the heat exchanger, and I decided to buy a new one, which I did. I'm going to repair the old heat exchanger of the geyser, I'll tin and solder the tube along its entire length. Photo of the heat exchanger from the side attached to the base.

When purchasing a heat exchanger for a geyser, I was surprised to find that they gave me not a new one, but an already repaired one. The heat exchanger tube had the same soldering that I did when repairing my old heat exchanger. As a result, out of four available in the store, only one heat exchanger was not soldered. It turns out that the plant ships repaired heat exchangers for spare parts that failed during the warranty period. They seal fistulas in them and sell them again. The heat exchanger has a warranty period of only 1 month. It turns out that in a few months the gas water heater will have to be repaired again!

If you have to buy a heat exchanger for a geyser, carefully inspect it. If soldering is detected, it is better to refuse the purchase. If you replace a heat exchanger in a gas water heater under warranty, make sure that you are not getting a refurbished heat exchanger that was in use, but a new one.

Repair of a replaced geyser heat exchanger

For almost three years, the NEVA LUX-5013 geyser worked properly after replacing the heat exchanger, but the happiness did not last forever, and suddenly water began to drip from it. I had to do the repairs again.

Removing the casing confirmed my fears: a green spot appeared on the outside of the heat exchanger tube, but it was dry, and the fistula, from which water was oozing, was on the side inaccessible for inspection and soldering. I had to remove the heat exchanger for repairs.

A problem arose while searching for the location of the fistula on the back of the removed heat exchanger. The fistula was located at the top of the heat exchanger tube and water oozed from it and flowed along all the tubes below. As a result, all the turns of the tube below the fistula on top turned green and were wet. It was impossible to determine whether this was a single fistula or whether there were several.

After the green deposit had dried, it was removed from the surface of the heat exchanger using fine sandpaper. Visual inspection heat exchanger tubes did not allow us to detect blackened spots. To find leaks, we had to pressure test the heat exchanger under water pressure.

To supply water to the heat exchanger, the above-mentioned flexible hose from the shower head was used. One end of it was connected through a gasket to water pipe supplying water to the gas water heater (on the left in the photo), the second is screwed to one of the ends of the heat exchanger tube (in the center of the photo). The second end of the heat exchanger tube was plugged using a water tap.

As soon as the water supply tap to the gas water heater was opened, drops of water immediately appeared in the suspected locations of fistulas. The rest of the tube surface remained dry.

Before soldering the fistulas, it is necessary to disconnect the flexible hose from the water supply network, open the plug valve and drain all the water from the heat exchanger, blowing it out. If this is not done, then the water will not allow the soldering area to be heated to the required temperature, and the fistula will not be able to be soldered.

To solder the fistula, which was located on the bend of the heat exchanger tube, I used two soldering irons. One, with a power of 40 W, was placed under the bend of the tube for additional heating, and the second, one hundred watt, performed soldering.

Recently purchased a farm construction hair dryer, and soldered the fistula in a straight section, additionally heating the soldering area with it. It turned out that soldering with a hairdryer was much more convenient, since the copper heated up faster and better. The soldering turned out to be more accurate. It’s a pity I didn’t try to solder the fistula without a soldering iron, using only a hair dryer. The air temperature from the hair dryer is about 600˚C, which should be enough to heat the heat exchanger tube to the melting temperature of the solder. I'll definitely check it during the next repair.

After the repair, the place of the heat exchanger tube where the fistula is located is covered with a millimeter layer of solder, and the path to water is reliably blocked. Repeated pressure testing of the heat exchanger showed that the tube was leak-tight. Now you can assemble the gas water heater. Water will no longer drip.

I bring to your attention a short video on how to solder a gas water heater radiator.

It is worth noting that with the help of the presented technology it is possible to successfully repair not only the heat exchangers of geysers, but also copper heat exchangers and radiators of any other types of water heating and cooling devices, including copper radiators installed in cars.

Restoring pipe flanges
geyser soldering

Somehow my eye caught two pieces of copper tubes with flanges, onto which American union nuts were put on. These parts are designed for installing a water supply system made of copper pipes.

When soldering the heat exchanger of the gas water heater, I remembered them, and the idea arose to restore the previously cracked copper pipe connecting the outlet pipe of the heat exchanger to the hot water supply, soldering to them new flanges that had been collecting dust on the shelf. The task was somewhat more complicated, since the copper tube for the available parts was bent at a right angle. I had to take a hacksaw for metal.

First, a part of the tube with a flange was sawed off at the place where the bend begins. Next, the expanded part of the tube was sawed off from the opposite end for further use as a connecting ring. If the tube were straight, there would be no need to saw. The result was two pieces of tube about a centimeter long.

The next step is sawing off the cracked flange from the pipe. The sawn piece of pipe should be equal in length to the section of pipe with a flange prepared for repair in the previous step.

As you can see in the photo, the sawn-off piece of the gas water heater pipe had many cracks at the place where the flange formed.

The photograph shows parts prepared for soldering. On the left is the end of the gas water heater pipe, on the right is a new flange with a union nut, in the middle is a connecting ring.

Before soldering, you need to check how the prepared parts fit together. The pipes of the nozzle should fit into the ring easily, with a small gap.

Before joining by soldering, the mating surfaces of the tubes and rings must first be cleaned with fine sandpaper to remove the oxide layer. It is convenient to clean the inside of the ring by wrapping sandpaper around a round rod, such as the handle of a small screwdriver. Next, the cleaned surfaces must be tinned with a thin layer of POS-61 tin-lead solder using a soldering iron with a power of 60-100 watts. As a flux, it is best to use acidic zinc chloride flux, in other words, hydrochloric acid slaked with zinc. Since copper parts are soldered, rosin or aspirin will also work.

When soldering, you need to ensure that the joint of the pipes is inside the ring approximately in the middle. If after tinning the tubes do not want to fit into the ring, then you need to heat them with a soldering iron, the solder will melt and the tubes will fit. Do not forget to put a union nut on the tube before soldering the pipe.

Once the tubes are joined, all that remains is to fill the gap with molten solder. As you can see in the photo, the result is a completely sealed and mechanically strong connection. The pipe has been repaired, and you can install it in place in the gas water heater; it will serve no worse than new.

The check showed that the pipe was tight at the soldering point, but a leak arose at its other end, and a microcrack appeared for the same reason. I had to repair the other end of the pipe in the same way. The geyser has been working with the repaired pipe for more than a year. No water leaks were observed.

Using this technology, it is possible to restore the tightness of not only copper and brass tubes, but also stainless steel and iron tubes. The technology is applicable not only for repairing geysers, but also for repairing other devices and machines, including cars.

Connecting the flue pipe
to the geyser umbrella

To repair the heat exchanger, it is necessary to dismantle the gas exhaust pipe. When installing this pipe in place, it is necessary to ensure the tightness of its connection with the geyser hood.

Even a large gap of up to a centimeter can be easily sealed using asbestos soaked in water. This is a heat-resistant material that is available in sheet form. In water, asbestos disintegrates like cardboard and forms a soft mass that molds well. After drying, asbestos becomes quite hard and dense again. Asbestos can be reused. Soak the extracted pieces of it in water.

The functioning of the gas water heater is ensured not only by the burner, but also by the presence of a heat exchanger. It is designed to transfer heat from the gas burning in the body of the water heater to the coolant flowing through copper tubes. If this component fails, the entire column will malfunction.

Before you start soldering the column heat exchanger, it’s worth figuring out whether it’s profitable. If you do the math, the cost of a new heat exchanger, including delivery and replacement work, will still be lower than a complete replacement of a geyser. In addition, you can solder the heat exchanger yourself.

During the work you will need the following tools and materials:

• soldering iron with a power of more than 100 W;
• fine sandpaper or metal brush;
• lead-tin alloy solder;
• flux - rosin or crushed aspirin will be enough.

After this, you can proceed to inspect the gas water heater to determine the location of the leak. Do not rush to turn off the water supply.

First, remove the outer casing from the device; if necessary, unscrew the bolts. Open the water and inspect the heat exchange element of the column to identify the location of the leak. If the hole (fistula) is easy to reach, then the heat exchanger can be soldered right on the spot without removing the entire gas column.

To work in a hard-to-reach place, you will need to dismantle the water heater, so turn off the tap at gas pipe, all the coolant is drained from the column heat exchanger by opening hot tap and unscrewing the nut on the cold water pipe. It is even easier to drain water from modern models of dispensers with plugs - you need to open the plug so that the water flows out by gravity.

Please note that before moving on to the work of soldering the fistulas, the heat exchanger should be dried - you can use a vacuum cleaner or compressor. Otherwise, the brazed heat exchanger will soon start leaking again as the leak will soon recur.

The area of ​​the heat exchanger where a leak was discovered should be cleaned with a metal brush or fine sandpaper. Often, characteristic green spots appear on damaged areas, indicating copper oxidation.

Stripping must be done carefully as the thin copper tubes are easily damaged. Upon completion of this procedure, the work area should be degreased with a special alcohol-based composition or any other.

Soldering methods

There are three main ways to solder a heat exchanger in a gas water heater. They differ in the tools they use.

Using a soldering iron

IN in this case For soldering you will need a good soldering iron with a power of more than 100 W, solder and flux.

First of all, flux is applied to the soldering site - a special paste, rosin or aspirin. This component allows you to clean the surface of oxide so that the solder is distributed more evenly.

The solder layer must reach 1-2 mm so that the soldering area can withstand the coolant pressure in the circuit.

Gas-burner

To solder holes in the heat exchanger in this way, you will need a torch, a liquefied gas cylinder, solder and flux. After connecting the burner, ignite it, adjust the intensity of the flame - it should not be high, so as not to damage the coolant elements of the gas water heater during soldering.

The fistula in the copper pipe is dried with a torch to remove any remaining moisture. Flux is applied (usually borax powder). Then they begin to gradually warm up the pipe itself so that the solder applied further begins to melt.

Upon completion of soldering, the remaining flux is carefully removed so that it does not corrode the surface of the heat exchanger pipe.

Cold welding

Using chemical method When soldering using cold welding, it is advisable to use a material that will retain strength and will not melt when in contact with hot water. Otherwise, a fistula will form again in the brazed plate heat exchanger, and work will have to start all over again.

When working with cold welding, gloves are required to protect your hands. A small amount of the substance should be kneaded in your hands for about 3 minutes. When the weld begins to harden, the patch is applied to the leak and pressed tightly until it sets completely.

In cases where the heat exchanger has leaked in several places at once, or the fistulas are very large, it is advisable to solder a patch from a copper plate or a piece of copper tube.

How to check for leaks

After soldering the geysers, you need to check the tightness of all pipes. To do this, they are carefully examined to see even the smallest fistulas - their presence is indicated by small green spots. To avoid re-disassembling the column in the near future, these defects are also cleaned and soldered.

After this, you need to connect water to the gas water heater with a soldered heat exchanger and open the tap.

Water is supplied slowly and gradually so that it displaces the air from the column. Once the entire heating system has been filled, the tap can be opened to full capacity. In this way, the strength of soldering joints is checked under maximum water pressure. At the same time, the soldered joints are re-inspected for water leaks.

At the very end, the boiler with a gas water heater is turned on to check its performance when in contact with hot water. In this case, the soldered areas can be wiped with a dry cloth to detect the slightest signs of moisture.

Flange repair

Sometimes soldering may be required for copper pipes located at the junction of the water supply with the outlet pipe of the heat exchanger. In this case, you can use pieces of copper pipe with flanges and American union nuts - they are usually used for installing a water supply system from copper pipes.

If you have straight pieces of pipe, there is no need to modify them, but curved pieces need to be cut off. At the bend site, a piece of pipe with a flange is cut off. The extended section of the pipe located on the other side also needs to be sawed off. It will be used later as a connecting ring.

Now you need to cut off the cracked flange from the pipe on the gas water heater. Its length must correspond to the pre-prepared tube with a new flange.

Before starting further joining, you should make sure that the elements fit together freely - the heat exchanger pipe fits into the ring with some clearance.

To improve adhesion, before soldering, it is recommended to sand the surface of the tube and ring with fine sandpaper until the oxide layer is completely removed. A thin layer of solder is applied over the prepared areas with a soldering iron with a power of 60-100 W; you can use tin-lead POS-61. The flux in this case can be either hydrochloric acid quenched with zinc, rosin or aspirin.

When starting to solder a tube to a flange, make sure that the junction of the two pipes is located in the center of the connecting ring. In cases where, after applying a layer of solder to the surface of the tubes, they will not fit into the ring, the surface should be heated with a soldering iron to melt the solder. Make sure that the union nut is placed on the tube before soldering begins.

When the joining of the elements is completed and they are positioned properly, the soldering of the heat exchanger is completed. To do this, the gaps between the elements are filled with molten solder.

Model differences

note that various models geysers can differ significantly in their design - this must be taken into account if you plan do-it-yourself repair water heater. So, Chinese geysers of the Vector brand are not worth soldering at all. The fact is that the radiators in them are formed from very thin copper tubes, in which new fistulas are formed during the soldering process. Thus, if you have a cheap column, it is best to replace the heat exchanger in it with a new one rather than repair it.

In terms of reliability and quality, among the best representatives of speakers are Oasis brand products from a German manufacturer. They are equipped with heat exchangers that have a long service life. Since the components for such equipment are quite expensive, repairs will be advisable. Soldering leaks on the heat exchanger of the Oasis column will allow it to be used for a long time.

In the middle price segment there are gas water heaters from the Swedish company Electrolux and domestic Niva. In such products, heat exchangers with anti-corrosion protection are installed, the soldering of which will significantly extend their service life.