Deterioration in heating performance can be due to several factors. One of them is airiness - the appearance of voids inside pipes and radiators. At the same time, the circulation of the coolant becomes more difficult, the efficiency is significantly reduced and the risk of breakdowns increases. How to remove an air lock from the heating system on your own? To do this, you need to find out the main factors for the appearance of such a defect.
Causes of air pockets
The formed air plug in the heating battery can occur for a number of reasons. The main one is coolant leakage. Even a slight decrease in the volume of water in the system entails the formation of air gaps in pipes and radiators.
In addition, we must not forget that water is characterized by the degree of oxygen saturation. During heating, not only expansion occurs, but also steam is released. It can be concentrated in the upper points of the highway. Most often, an air lock in a heating radiator is formed precisely because of this. After the coolant cools, its volume decreases, the resulting space is occupied by air. During the operation of the system, in order to avoid the occurrence of these phenomena, the following recommendations should be followed:
- Compliance with the level of the location of pipes and heating appliances. Even a slight skew of the battery will pose a question to the owner - how to expel an air lock from the heating system;
- The use of system elements, the material of which does not allow oxygen molecules to pass through. The most common mistake is the installation of XLPE pipes without a protective sheath;
- Compliance with the operating modes of heating. This applies to both the temperature curve of operation and the pressure. To do this, manometers and thermometers should be mounted on critical sections of the highway;
- For closed systems, it is recommended to install automatic replenishment with coolant. In the event of a decrease in even a small amount of water due to leakage or evaporation, this mechanism will automatically add the required amount of coolant.
But how to break a cork in the heating if it has already formed? First you need to find. A clear sign of its appearance will be a sharp drop in temperature at a certain point in the pipeline or radiator. There will also be characteristic sounds - gurgling and fluid flow. Gentle tapping will help to find the exact location of the defect. At this point, the metal will create slightly higher sounds than when completely filled with water.
If it is necessary to avoid a situation in which it is difficult to remove the formed air lock from the heating pipes, it is recommended to install a separator after the boiler. This device reduces the amount of gas in the water.
Methods for eliminating air congestion
Before you remove the airlock in the heating, you need to find out its properties. Chief among them is the density, which will always be lower than that of water. Accordingly, the liquid will displace air up and in the direction of circulation.
Therefore, to remove airiness, it is necessary to ensure the release of steam. To do this, you should install special devices - air vents and Mayevsky taps. They work on the principle of a check valve. When a certain pressure is exceeded, steam acts on the valve seat. The rod moves, releasing air from the radiator or pipe. After the normalization of pressure under the action of the spring, the rod takes the old position.
An air lock in a cast iron or aluminum radiator can damage the housing. Therefore, when such a situation arises, it is necessary to immediately solve the problem.
Mayevsky crane
It is designed to eliminate the air lock in the heating battery. Despite its small size, Mayevsky's faucet contributes to the effective removal of accumulated steam not only in radiators, but also in pipes.
Structurally, it is a needle valve enclosed in a metal case. How to remove an air lock from the heating system with it? First you need to decide on the device model.
Manual taps
After installation in the upper branch pipe of the radiator, air is released after turning the union nut on the tap. Removing an air lock from the heating system using a Mayevsky manual crane is performed according to the following scheme:
- Filling the system with coolant. The valves on the radiators are in the closed state;
- When the maximum level is reached, the water supply stops;
- Having set the required gap of the needle limiter in the devices, the taps open;
- At the same time, the coolant supply is resumed.
Water is added to the system until liquid begins to flow from all Mayevsky's taps. Be sure to check the absence of an air jet. This method is effective for removing an air lock in heating radiators when the system is first started, before the season, or when air is released during operation.
Manual models will effectively eliminate the air lock in the radiator for both autonomous and central heating. The main thing is to choose the right mounting thread. In most cases, it is equal to 1/2”, but there are models with a non-standard size of 3/4”.
Automatic taps
In contrast to the model described above, in their design, a seat with a certain surface area is installed on the end of the needle valve. In combination with a return spring, the degree of pressure of which determines the critical pressure value at which the valve opens. A detailed device is designed to automatically break through a plug in heating when a critical temperature value and, as a result, pressure is exceeded.
However, before installation, you should familiarize yourself with the specifics of this model:
- To prevent water from entering the floor, a pipe must be provided in the structure to drain excess water into the sewer;
- If left standing for a long time, the valve seat can become covered with limescale, which makes it difficult to open it. Therefore, it is recommended to open the tap manually once every 2-3 months. The steps of the procedure must be done before the first start of heating;
- The set maximum opening pressure must not exceed the critical value of the whole system. In order to remove the air lock from the heating in automatic mode, the pressure value on the tap must be less than the maximum by 5-10%.
What is better to install: automatic or manual Mayevsky crane? If the operation of the system does not provide for sudden pressure surges, manual models can be placed on the radiators. For autonomous heating, automatic heating is preferred.
It is best to choose models made of brass. During the expulsion of the air plug from the heating, they can withstand not only the critical pressure value, but also the temperature. The steel case is subject to destruction and rusting.
Heating air vent
But in addition to radiators, situations often arise when it is necessary to expel an air lock from the heating system in the pipes. To do this, it is necessary to install air vents in certain sections of the highway. Their design is in many ways similar to the described Mayevsky automatic cranes. However, there are significant differences - they are designed for the largest volume of air released and are not installed horizontally, but vertically.
In order to remove the resulting air lock from the heating system, you first need to install air vents in the right places:
- At the highest point on the highway. For an open system, this is only possible if a sealed expansion tank is installed on the return pipe;
- In collector heating - on each comb;
- For tee wiring - in front of each trunk branching node.
After installation, it is necessary to correctly set the pressure value at which the air vent will work. To remove an air lock from the heating system, a coolant is injected into the pipes until the air vent on the return line works.
Removing the airlock in autonomous heating, you need to reduce the temperature of the coolant to a minimum. This will reduce the volume of water and help you troubleshoot more effectively.
In combination with the functional qualities of Mayevsky taps, this makes it possible to effectively break through any plug in the heating. It is important that the response parameters of the devices do not exceed the critical pressure value. Otherwise, the security of the system may be compromised.
The video shows an example of airing a heating radiator:
Apartment owners in apartment buildings and everyone who has central heating have often encountered the problem of air congestion in heating systems. This is expressed in the appearance of various noises, poor heating of the batteries and corrosion of metal parts.
It is characteristic that even from an ideally designed and executed central heating system it is necessary to bleed air from time to time. Its appearance inside is possible not only because of the possible poor tightness of the system, but also for other reasons.
Causes of air entry
Consider the reasons why air jams occur:
- In case of heating repair.
- In apartments, it is rather difficult to ventilate the pipes by immediately filling them with water.
- This problem is often found with underfloor heating, in cases where their lines are not completely horizontal.
- The appearance of gas in water is always associated with an increase in its temperature. In autonomous heating systems, air does not remain after a while, however, if the coolant is constantly updated, the problem will appear again and again.
Problem Definition
To identify air congestion in heating, you need:
- try to touch the batteries, and in the case when part of the surface is cold or barely warm, this will mean there is air in the system;
- if the temperature in the room has dropped for no reason;
- if you hear gurgling in the radiator.
It is very easy to check whether the system needs to be bled by tapping a metal object on the top of the battery, and then do the same in its bottom part. At the site of the cork, the sound will be more sonorous.
Consequences of airy heating
If the plug is not released in time, prolonged contact with oxygen will negatively affect the metal, and it may become covered with scale, and destruction will begin. In addition, the airiness of the system affects the circulation of water, as a result of which some places overheat and others are slightly heated.
There are various ways to bleed gas, and priority should be given to one or the other depending on the choice of coolant. And also, from the method of water circulation in the system: natural or forced.
As a result, an air valve is used to release an air plug from the radiator or a Mayevsky crane.
How can you let the air out
Forced circulation systems use a small bleed air box at the top. However, bleeding is possible only if the supply pipe is at an angle in the direction of the coolant flow.
In this case, the air pockets that rise with it will exit through a series of special valves.
To date, the use of manual and automatic methods is more often used to bleed air and water into the system. Hand-held devices (Maevsky cranes) are distinguished by their compact size
Consideration: it is possible to bleed only after the coolant has completely cooled down.
Features of automatic air vents
In order to bleed air into, such as underfloor heating in a house, human participation is not required.
High performance does not reduce the strong sensitivity to impurities in the coolant, so they are installed together with filters. Filters are installed both on the supply line and on the return line. In order to most effectively remove air, their design has steps, which allows you to remove oxygen from each group of devices.
If the pipes were installed in a private house slightly at an angle in the direction of water flow, the release mechanism allows you to ventilate the heating with a high flow rate of the coolant, and increases the pressure.
Removal of air through the bleeder in aluminum, bimetallic and cast iron batteries
The advantages of aluminum batteries are affordable price and excellent thermal conductivity. But aluminum is not a very good material for heating, due to its ability to react and release hydrogen.
When such a battery is air-filled, the Mayevsky crane will help to solve the problem of dumping excess air. In order to expel hydrogen from the inside, such batteries are covered with a special film, but this is only enough for a while, and then the gas is not removed.
Bimetal radiators are another great invention. Where the internal parts touch the water, a different metal is used and the fins are made of aluminium. In cases where a thermostat is installed on the radiator, opening it will allow you to bleed the system and release oxygen. The airing of such radiators is similar to other varieties.
Details of the use of thermostats in heating radiators are discussed in this article:
Cast iron batteries are also vented through a Mayevsky crane or an automatic air vent, so that plugs can be removed from the pipes.
Using the Mayevsky crane
The device is very popular due to its simplicity. If the system is airy, it helps to blow out excess air in the heating pipe. The Mayevsky crane is a compact, convenient air vent that is mounted on the side of the battery. When the pipes are airy, you should take a screwdriver and a small container, because in addition to releasing air, some water will flow out.
It's important to know: air will shorten the life of the water pump!
Use a screwdriver to unscrew the tap and substitute the container. Further, if there was a cause for airing, you will hear a hiss, after which the air will begin to come out with drops of water through the air vents. The air will be completely deflated when a small trickle of water flows through the vent. This will increase the life of the boiler. While the system is pushing through the gas bleeder, water droplets may form.
Using the automatic air vent
For ease of bleeding, you can install this device, especially on bimetallic batteries. It has a float that tightly closes the discharge hole when there is water in the system. When air enters, the float lowers and releases it out.
True, in order for the devices to work correctly, it is recommended to use only very clean water, which is practically not found in heating systems. So you need to set filters.
Before that, you need, which takes a lot of time. However, even this cannot guarantee you the correct operation of the mechanism, since sometimes it will need to be cleaned.
Note: there are times when you need to shake the battery a little to push the air. In it is possible to install a conventional faucet with power supply in the water supply at the bottom of the battery. If you need to release air, open the tap and let the water in. This allows it to be driven through the system, and pushes air through the air vent system.
If the heating installation sites have the wrong slope, additional air vents can be installed.
Air may also appear in the water supply system, which negatively affects its operation: pipes and adapters are destroyed, air in the pipes can provoke a water hammer, cracks appear and the pipe bursts. Ball valves, valves, automatic air vents, Mayevsky valves help get rid of air in the water supply system.
Watch the video in which the specialist tells how to determine the airiness of the system and how to bleed air from the batteries:
Before starting the heating system, it is important to properly prepare it. If a person lives in a city high-rise building, this problem is unlikely to affect him. After all, the employees of the housing office are responsible for carrying out such a procedure. But the owners of the private sector start the heat on their own. But even during the heating season, batteries can heat poorly, and in some places even be cold. Probably the system is vented.
In any case, you need to know how to bleed air from a heating radiator in order to avoid situations associated with inefficient operation of the equipment. Why an airlock occurs, its consequences for the operation of the heating device, what are the methods for removing it - you can find out about all this by reading the article.
If there is air in the battery, nothing good will come of it. Excess air is an obstacle to the normal functioning of the system. And it can also cause corrosion on the walls of the radiator.
If it is installed in the circuit, an air lock can also disrupt its operation. When the system is functioning correctly, the plain bearings on the shaft of the pump unit are constantly in the water. And in the presence of air, the effect of "dry friction" occurs, which negatively affects the sliding rings, and can damage the shaft. Therefore, it is important to know how to expel air from the heating system at home. Measures taken in time will help prevent damage to the heating network.
How to understand that there is an airlock in the battery?
Before you release air from the heating system, you need to figure out why it is formed in the circuit and how to understand that there is an air lock in the radiator. Most often, excess air accumulates as a result of improper filling of the system with water. The reason may also be the result of errors made during installation. Low pressure in the circuit, low-quality coolant with the presence of dissolved oxygen can also lead to airing.
Air lock can also occur under such circumstances:
The following signs may indicate that excess air has accumulated in the system: hissing and gurgling sounds in the battery, the quality of heating decreases, heating becomes uneven, and the radiator may be cold in areas where air is present.
Such situations are not uncommon. Surely every owner of an apartment or a private house faced a similar problem. Therefore, it is important to figure out how to remove air from the heating system at home, especially since it is not at all difficult to do it yourself. It should be noted that most often an air lock is formed in batteries that are installed on the upper floors of the house.
Important! Sometimes the cause of plug formation is a low quality radiator.
In this case, no matter how much you bleed excess air, it will form again. And the reason lies in the fact that the material from which the battery is made contributes to the formation of gases. There is only one way out of the situation - to buy a new radiator. Therefore, it is better to immediately purchase heaters from conscientious manufacturers.
How to remove excess air from the battery?
Before you bleed air from the heating system, you need to understand the features of this procedure well and prepare all the necessary tools and materials. Consider how to remove air from the heating system in more detail. For such work, you will need a special key with which you can open the air valve on the radiator.
A radiator wrench is best. It is sold at any hardware store. If a modern battery is installed, you can take a simple screwdriver. It is also necessary to prepare a container into which the coolant will merge. And also have a couple of rags nearby in case of unforeseen situations.
The algorithm of actions on how to properly bleed air from the heating system is given below:
In addition to Mayevsky taps, automated air vents for heating systems are often used, which bleed excess air on their own. Such automatic units are compact and reliable. But at the same time, you have to be extremely careful. After all, the valve works without supervision. And the slightest violation in the process can cause flooding of the attic or riser.
Some nuances
There are situations when the masters, when installing the heating system, do not install special valves to release excess air. Let's consider how to release air from the radiator in this case. To work, you will need an adjustable or gas wrench. Use it to open the cap. This must be done very slowly. Sometimes the plug won't open. Most often this happens if . In this case, it is necessary to apply a special lubricant to the thread and after a while try again.
When the plug is unscrewed, the same algorithm of actions is performed as with a conventional tap. When the cork is screwed into place, one must not forget to wrap either FUM tape or linen on the thread. This will avoid leaks and give the connection a tight seal.
If air has accumulated in the heating system of a private house, the water will have to be drained using an expansion tank.
This container is always located at the highest point of the heating system. When the water is drained, you need to wait a bit, and then unscrew the tap on the expansion tank. Usually, when the temperature of the battery rises, the cork comes out on its own. If such actions turned out to be ineffective, then the water in the circuit should be brought to a boil. In this case, the cork will definitely come out.
How often do you need to bleed air?
Knowing how to bleed air from the heating system can prevent and solve many problems. But how often should such a procedure be carried out for prevention purposes? As a rule, this should be done at the beginning of the heating season. Twice is enough (the first time for verification, the second for control). Of course, if there are defects in the system or it is faulty, then the number of descents can be large.
If the apartment is installed, then before starting the system, it is necessary to drain the water. This will help increase battery life significantly.
Preventive measures
Of course, knowing how to blow out a heating battery is important and necessary. But it is better to air the system as little as possible. It is better to prevent this situation and install an air vent.
At the moment, the air collectors of heating systems can be of two types: manual (represented by the Mayevsky crane) and float (or automatic). Each of the above types can be installed in various places where there is a risk of air entrapment. The Mayevsky crane configuration is traditional. Auto air vents can be angled or straight.
In order not to puzzle over how to ventilate the heating system, it is imperative to install an air vent on each battery.
Manual air vent type
Manual type air vents are usually mounted on the front side of the radiator. With their help, you can easily bleed excess air. It is enough to have only a special key. The performance of such devices is small. Therefore, such an air collector for the heating system is installed only for use at home.
Automatic air vent type
As for automatic air vents, they operate offline. You don't need to unscrew or open anything. The device does everything on its own. Mount them strictly in a horizontal or vertical position. But I must say that such a valve for bleeding air from the heating system has one drawback - high sensitivity to pollution of a different nature. Therefore, it will also be necessary to additionally install a filter that will clean the device from mechanical impurities.
Important! If air has formed in the heating system, you should find out the reason for this situation. Especially if there were no such problems before. It is important not only to remove the airlock, but to take all measures so that it does not reappear. Therefore, it is necessary to check the device for tightness. Perhaps somewhere you should change the nuts or tighten the bolts, better seal the joints. Or perhaps the air vent is installed incorrectly or the automatic air separator for heating is out of order.
Outcome
Summing up, we can say that the problem of airing the system is quite relevant. It can occur both in urban high-rise buildings and in private homes. There can be many factors for the formation of excess air. It is very important to establish the true cause and know how to bleed air from the heating radiator correctly so that similar situations do not occur in the future.
An important role in the proper and efficient operation of radiators is played by the installation of special air vents. By installing such a device, the owner of a house or apartment will be able to forget about the problem of air jams, save time and money, and also extend the life of the entire heating system.
The heating system needs constant monitoring. Often, air congestion occurs in it, which disrupts its functioning and can cause an emergency. To avoid this, you need to know ways to help bleed the air from the batteries. Thanks to this, it is possible to improve the quality of space heating and eliminate unpleasant sounds that often appear in such cases.
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Causes of airiness
Although the heating system is airtight, air often accumulates in it. Especially often this problem is observed in multi-apartment and private houses in the first days of the heating season. The main reasons that provoke it are the following:
In some cases, airing is associated with the composition of the water. To fix the problem, you need to install a special filter. In private homes, plastic pipes are often used., so the appearance of an air lock may indicate the use of low-quality barrier valves during installation.
Signs and dangers of air locks
Some argue that it is not necessary to air the battery in an apartment or private house before the start of the heating season, but this opinion is erroneous. If you take a thermal image of a radiator that contains air bubbles, you can see that the places where they accumulate have a low temperature. They are cold to the touch.
That is why when the system is aired, the heating efficiency drops noticeably. Even when the temperature outside does not drop below -3 °C, the room will be cool. In a private house, during the operation of a heating boiler, there is also a low heat transfer associated with the presence of air in radiators or pipes.
The owner of the house, when trying to start the heating system, can hear murmuring and gurgling in the batteries, which indicates the need to lower the air masses. In some cases, the sounds are sharper and resemble a knock on metal with a wooden stick. It is urgent to correct this, as a malfunction of the boiler is possible. If there are no signs, but the radiators still heat up unevenly, you can knock on them in different places with a metal object. In the area of accumulation of air masses, the sound is louder and higher.
In the presence of a large amount of air, the pump that helps fill the heating system with water simply cannot push it into the pipes. This results in a sharper and louder knock. This often leads to failure of not only the pump, but also the boiler, since the latter overheats due to the lack of normal circulation of the coolant.
Tap on the battery - for air release and water drain.
In addition, the metal of batteries and pipes, upon prolonged contact with air, begins to thin out, areas of corrosion appear, which gradually disable the device. It should also be borne in mind that constant and uneven heating of the material harms the system and provokes emergency situations. That is why it is recommended to bleed air from heating radiators at the first signs of traffic jams.
Ways to solve the problem
Today, there are several ways that help to release air from the radiator. In apartments and private houses, this process may differ. As a rule, this is due to the principle of operation of the system in the house, and in multi-apartment buildings, central heating functions in the same way.
To work, you need a special adjustable wrench. If the radiator is a new generation (bimetallic or aluminum), then a regular screwdriver will do. It is worth keeping a sufficient number of rags nearby, as well as a wide basin, since water leakage is inevitable. After that, you can begin to lower the airlock using one of the popular methods.
Mayevsky crane
Mayevsky's crane is often used in apartments. It is a kind of needle-type valve located on the top of the battery. Models are available with and without a plastic handle. In the first case, no tools are needed. When working with a tap, there is no need to block the entire riser and wait for the coolant to cool. This will reduce the operating pressure. To bleed air, you must perform the following manipulations:
Next, you need to close the tap. If the manipulation was carried out in an apartment, the system is independently filled with coolant. In a private house, it must be filled again in the case when the pump is turned on manually.
Automatic air vent
Such a system is called a float, it is fully automatic and does not require human intervention. The air vent is installed on the radiator in a horizontal or vertical position, reacts to the amount of coolant and, when air masses accumulate, releases them. With a decrease in the amount of water, it lowers and automatically opens the valve that releases the cork. This is very convenient and eliminates various emergency situations.
#86. HOW TO BLEED THE AIR FROM THE HEATING RADIATOR?
However, the device has a drawback - it is very sensitive to the chemical composition of the coolant and, in the presence of a large amount of harmful impurities, quickly fails. Special water filters and regular replacement of the o-ring will help to avoid this.
An automatic air vent is considered an ideal option for a private house, since it does not require restarting the system and draining a large amount of water. With proper use, it can last a long time.
Battery plug
The previous methods are relevant provided that modern radiators are installed in the apartment or house. However, cast-iron batteries work properly in many buildings. It is problematic to properly bleed air from them due to the lack of a Mayevsky crane. Instead, special plugs are installed on the radiators, fixed with paint and tow. To bleed air, follow these steps:
Tighten the cap carefully, but firmly. It is recommended to additionally wrap the threads with a special tape, which will help to avoid leakage of the coolant. Only after fixing is it allowed to reopen the tap supplying water to the system. This method is rarely used in homes and requires certain skills. In their absence, it is better to contact a specialist.
In a private house
Mayevsky is installed in many houses, so when airing the system, you can use the same method as in an apartment building. However, usually such devices are not available, which is why the only way will be to descend through the expansion tank.
Such a device is an indispensable element of any heating system in the house. It can be open or closed. The first option is easier to operate, and airing the system usually means lowering the water level in the tank. To fix the problem, it is enough to replenish the missing amount of fluid.
If the heating system has a closed tank, the only solution to the problem is to bleed air through the radiators. Before this, it is recommended to try to completely fill the system so that at least 10 liters of water pour out of the control pipe coming out of the tank.
After that, you need to start the system again. If the problem persists, it is recommended to bleed air masses from the battery, following the general recommendations. It should be noted that in old-style heating systems, air in the radiators may appear during intensive operation of the heating boiler.
This is especially often observed when installing solid fuel models without a built-in thermostat. The water heats up excessively, begins to boil away and pour out through the control pipe of the expansion tank. As a result, it becomes empty and in the presence of cracks that violate the tightness, air masses begin to enter the system. It is then possible to bleed air in any of the listed ways, but before that it is necessary to eliminate holes or cracks. Otherwise, the descent will have to be repeated regularly.
How to bleed air from the Audi 80 cooling system. [@2015]
Prevention methods
In order to constantly not bleed air from the radiators, it is necessary to perform all actions correctly when starting the heating system. The open type of the system provides for self-filling of pipes with coolant. To do this, open all the valves, ensuring the unhindered movement of water.
The pressure should not be too great. It is recommended to pay attention to the drain valve, which must be closed when filling the radiators. If the heating system is closed, the algorithm is somewhat different. The first step is to close all valves, except for the one that starts the water. Next, you should connect a pump that provides stable pressure in the pipes. The next step is to fill the system with coolant. Only after that should air be bled from the radiators using the Mayevsky crane.
Air in the battery is a common problem in homes and apartments. preventing normal heating of the room. When following the recommendations of specialists, an ordinary person without professional skills will be able to cope with it.
It is not uncommon for radiators to suddenly stop heating during the heating season. One of the reasons for the failure of the system is an air lock, and then the residents face the problem of how to bleed the air from the radiator in order to restore circulation. There are several effective ways to normalize heating and how to bleed air from the system. In this case, the procedure should be determined depending on the type of heating system and the specific place where air accumulates.
The appearance of an air pocket
It is quite easy to detect that an air lock has formed in the heating system. Signs of airing the system:
- gurgling sounds are sometimes heard in pipes and radiators;
- batteries either do not heat at all, or only heat up to half;
- Some rooms are hot, while others are not warm.
This means that the accumulated air is to blame, and how to release it from the heating system must be decided in accordance with exactly where it has accumulated. Air bubbles always accumulate in the upper part of the heating system, therefore, radiators in rooms on the top floor most often cool down. To find the location of the air lock, you need to consistently feel the supply pipeline and all batteries, checking the degree of their heating. It is also advised to tap the pipes with a hammer and determine by the sound where the void has arisen, but this must be done carefully so as not to damage the paint layer on the pipes.
As a result, having found a problematic place, it is already possible to choose a method of how to bleed air from a heating radiator or, if necessary, from a pipeline.
The air lock not only interferes with the circulation of the coolant, but provokes corrosion of metal pipes. The presence of air in the system also negatively affects the operation of the circulation pump.
Where does air come from in the system?
The reasons for the formation of an air lock can be both natural and related to improper system design and poor-quality installation.
Naturally occurring causes:
- when the coolant is heated, the air dissolved in the liquid is released, it rises up and forms a plug;
- gas bubbles appear in the process of interaction of a hot coolant with certain types of metals (in particular, aluminum);
- due to evaporation, the liquid level in the open expansion tank drops below a critical value;
- the air does not have time to completely exit the pipes and batteries if the system is too quickly filled with water with a complex configuration.
It is important to know how to drain the heating system if necessary and then refill it so that no air remains in the pipes and radiators.
In addition to natural causes, the appearance of air congestion also leads to:
- incorrect layout of horizontal pipes and installation of radiators;
- pressure drops in the feed water supply;
- poorly sealed connections;
- deterioration of old pipelines;
- expansion tank failure.
When during the operation of the heating system it turns out that it was originally designed incorrectly, it will have to be redone. But in order to urgently restore the heat supply, you need to decide how to bleed air from the heating system.
Air lock removal
If the heating is properly designed, then how to bleed the air out of it will not be difficult. It can be arranged so that the bleeding of accumulated air will occur automatically, as it accumulates. For this, special devices are used - air vents installed at critical points. In other cases, it is necessary to acquire skills on how to bleed air from the heating system in manual mode.
It matters:
- open or closed type of system;
- natural or forced circulation of the coolant;
- top or bottom piping option;
- whether the horizontal slopes of the pipes are observed.
Drain cock on the radiator
In apartment buildings, residents do not have a question about how to bleed the air from the heating, specialists of the management company should worry about this. Although in the old five-story buildings the heating is arranged in such a way that it is possible to bleed air from it only through the radiator in the apartment on the top floor, and the residents themselves periodically have to do this. The problem of airing looks more acute for owners of private houses with autonomous heating - it is sometimes necessary to bleed the air. To bleed air from a water heating radiator, a needle air valve is used, the so-called. Mayevsky crane. Such a device is installed at the upper end of the radiator battery, instead of a plug. Sometimes it is also used to bleed air from a heated towel rail pipe. Different models of Mayevsky cranes are somewhat different, so before you bleed air in heating radiators, you need to read the instructions. Open the faucet valve either with an open-end wrench, or with an ordinary screwdriver, or simply with your hand.
Let's consider how to release an air lock from a heating battery using the Mayevsky crane installed on it:
- prepare tools (wrench or screwdriver) and a container for collecting water;
- open the thermostat completely, then unscrew the Mayevsky tap half a turn;
- air will begin to exit through the valve with a slight hiss;
- substitute the container and keep the valve open, since it is necessary to bleed air from the heating radiator until water flows;
- when a dense stream of water appears, you can turn on the tap.
If, after you have bled air from the radiator, it still does not heat up well, drain another 200 grams of coolant through the same tap to completely remove the air lock.
Air bleed through expansion tank
In private houses, the arrangement of heating systems is different, it depends on the features of the layout of buildings. For different types of systems, appropriate expansion tanks are used - open or closed. Therefore, individual homeowners often have to think about how it is more expedient - to bleed air from a heating radiator or through an expansion tank .
In an open system, air bubbles have a free exit through an expansion tank installed in the attic. If the heating is working normally, there is no need to bleed air from the system, since it comes out on its own. But the liquid gradually evaporates, and the water level in the open expansion tank can drop so low that an air lock appears in the upper part of the supply pipe. In this case, the circulation of the coolant will slow down or stop altogether, and in this situation we should already be talking about how to bleed air from the heating system.
To drive out the air lock, you can add water to the expansion tank from above, but it is better to replenish the volume of liquid in the system through the bottom tap connected to the water supply. The water coming from below will fill the void in the pipe and squeeze the air out through the opening of the expansion tank.
During the heating season, it is necessary to ensure that the expansion tank is constantly filled with water to about 2/3 of the volume, and top up with water when the level drops.
In closed systems, diaphragm expansion tanks are used. Sometimes the membrane ruptures in them, and then air enters the system. If it is possible to establish that the cause of airing is a faulty expansion tank, it will have to be replaced. But before starting repairs, before draining water from the heating system, you need to prepare everything you need so as not to leave the house without heat for a long time.
What should be the correct structure of the system
When designing, it should be foreseen that air can accumulate in horizontal pipes, and how to drain it from the heating system will be a difficult task. Therefore, it is important that the top supply pipe has a slight slope, starting from the riser and further in the direction of the coolant. At the highest point, a device is installed that allows you to bleed air from the heating. It can be a regular faucet or Mayevsky faucet, but it is better to use an automatic air vent. In a more complex heating system, air vents are installed in all places where an airing problem may occur. Then there will be no question of how to bleed air in one or more heating radiators, since the accumulating bubbles will be gradually bled from each group of elements that make up the system.
