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How to bleed air from the heating battery

The main cause of the problem is water leakage. Even an insignificant loss results in air bubbles in radiators and pipes.

The following factors can provoke an air lock in the heating system:

bleed, heating, battery
  • Overheating of the heating system. This most often happens when the heating is started after a long period of downtime in the summer.
  • Improper installation. Even if quality components are used for the construction of the system, the slope of the pipes must be taken into account. Therefore, in the absence of skills yourself is not desirable to install and repair the system.
  • The release of too much steam. This can happen due to the use of water of poor quality and significant temperature differences.
  • Use of low quality aluminum radiators. Aluminum alloys can react with ingredients with impurities flowing water.
  • The fluid that moves around inside the radiators and pipes contains gases with different densities.
  • Mistakes in maintenance and repair, after which a large amount of air enters the heating radiators and pipes.
  • Significant pressure drop.
  • Incomplete depressurization due to damage and wear and tear.

In homes, PVC-pipes are used most often, so the occurrence of air in them can be a consequence of insufficient quality of the barrier air valves.

Even in private utility systems it is not possible to completely prevent air leakage. However, by following the rules of maintenance, you can reduce the likelihood of abnormal situations.

Symptoms of air lock, its dangers

To understand that there is an air lock in the battery, you do not need to be an expert. Its accumulation may be evidenced by:

  • “Merry” bubbling, gurgling, hissing that began after the start of the coolant at the beginning of the heating season;
  • Uneven heating. cold parts of the radiator: air, which is a good insulator, prevents them from heating;
  • noticeable vibrations in the piping due to contact between concentrated air and metal surfaces.

Large plugs give other symptoms: in this case the radiators remain cold even when the neighbors are fine. Detecting the problem is easy. You should take any metal object and tap it on the radiator. If the sound is loud, not muffled, you can say with certainty that there was a leak.

Metal batteries and pipes in prolonged contact with the air mass will thin due to corrosion processes during which it will begin to decay, forming carbon dioxide and salt. Another possible consequence is the formation of lime scale. As a result the clearance of the pipes will decrease, and therefore the system will already be functioning less efficiently.

The circulation pump, working in an autonomous system, if the air enters it can fail at any time. If the bearing gets into the air instead of water, it will overheat, and the worst thing that can happen is that it will break.

How To Easily Bleed A Radiator

Uneven heating or any damage to the heating system is detrimental, they can provoke emergency situations. For these reasons, owners are recommended to get rid of air as soon as possible.

Rules for Filling Liquid Heat Fluid

If the heating system is constantly filled with water, the formation of air, or rather gas congestion in it is possible only in a fairly specific process. In most cases choke heating occurs precisely in the process of pumping the coolant, so charging the system must be carried out in accordance with a number of rules.

The water supply pipe must be installed at the lowest point of the system, usually the return pipe section just next to the boiler or additional outlets in the manifold nodes. It is desirable to have a valve as a shut-off valve, not a ball valve. This is due to the fact that the water supply needs to be at a low pressure, and the valve in regulating the flow helps in the best way possible.

Water will be squeezed out when it enters the piping system and an outlet connection must be provided for this. It must be located at the highest point of the system and installed vertically. It is good if after the faucet will be packed with a fitting with a hose, the end of which is lowered into a bucket of water placed on the floor. Then the signal of the end of the filling will be the cessation of formation of air bubbles, squeezed out of the system.

Before draining water from the system, it is recommended to shut off all looped sections: circulation pump, closed expansion tank and radiators. If they are left filled for the duration of the repair work, it will slow down the corrosion of metal surfaces and prevent the formation of plugs during refilling of the system.

Types of circulation

You can bleed air from the heating radiator in several ways. A lot depends on the circulation, which is divided into two types:

For example, with natural circulation it is quite easy to bleed air from the battery through the expansion tank. It is located at the highest point. Make a laying of the supply pipe with the ascent to this tank. Typically, such a system is in private homes. After draining the water, wait a while and unscrew the tap on the tank. the plug should come out by itself due to the increase in temperature.

There are several types of distribution, which bleed air in different ways

If wiring in the apartment at the bottom, it is correct to bleed air from the battery in the same way as in the system with a circulating pump. Release the plug in the forced mode is simple enough: at the highest point is installed air collector, which is just designed to release air. In such cases, the pipeline is laid initially with the rise as it moves. air bubbles move along the riser, removal is carried out through air cocks (they stand at the top points for convenience).

The return pipe is always laid with a slope in the direction of drainage, so that it is possible to carry out rapid emptying during repair work.

The procedure of bleeding air is enough to carry out twice at the beginning of the heating start. to check and control. The number of descents can be increased if the system is faulty or there are some defects in it. In the case of aluminum radiators the water is drained first. this increases their service life.

How to remove excess air from the battery

Depending on the system, this can be done in two ways. If the installation foresees it, the air is drained by the automatic air vent. This device should be installed at the highest point of the riser pipe or behind the boiler when installing heating. Its advantage is exactly in full autonomy.

You can also install an air separator behind the boiler. This device catches not only air bubbles, but also dirt. But the cost, of course, is more expensive.

To deflate the air in manual mode, most often used Maevsky tap or, as it is also called, needle valve. They are inexpensive and very reliable. It is installed on top of each radiator and, preferably, in each complex section of the pipeline, where there is a bend or large height difference. This is a small sized cone with a sealed screw. To bleed air, it has a small hole, through which a lot of water can not pour out, which eliminates the possibility of flooding. To install such a valve, you do not need to be a locksmith. Only carefully select the device of the appropriate diameter. A Mevskogo cocks are installed after the water is drained from the system. Needle valves come in different designs and are mostly made of brass.

Order of operation:

  • Using a special key or a regular screwdriver to turn the screw on the faucet Maevsky a couple of turns counterclockwise. There is no need to unscrew it completely, the pressure in the system may prevent you from screwing it back in. This will not affect the speed of the process because the amount of air and water coming out is controlled by the diameter of the outlet on the side of the faucet. The air comes out of the radiator with a characteristic hiss.
  • Bleed until a thin even stream of water without any air is coming out of the hole. A container or a cloth should be placed under the tap beforehand to collect the dirt.
  • Screw the screw in the opposite direction.

Some details

  • Please note that a clog in the water pipe can be the cause of poor functioning of the radiator. Due to an accumulation of rust or dirt. You will know that the problem is not air when you try to drain the faucet with a strong jet, but no air.
  • The likelihood of an air lock is the higher the closer to the upper floor of your apartment in a high-rise building.
  • The drain outlet on the Maevsky valve can be positioned at different angles, this can be seen in the video below. It is worth making sure that it is not turned into the wall, to avoid getting the wallpaper wet. It is best to turn it downward.

Removing the air lock from the radiator:

How often does the air need to be bled?

During the heating season, the air is bled every time there is a strange noise or the temperature of the radiator drops.

To do this as a preventive measure is also recommended at the end of the season and in summer.

Signs of an air lock and its harm

You can suspect the presence of an air lock in the radiator by the following signs:

  • the air temperature in the apartment is significantly lower than that of the neighbors;
  • the radiator is heated unevenly. the part with air remains cold;
  • Sizzling and gurgling sounds can be heard.

Due to the accumulation of air in the radiator, the heating system is disturbed. Possible consequences:

  • reducing the effect of the battery. the air in the room is not heated to the required level at a significant expense of energy;
  • damage to the elements of the pipeline due to the difference in temperature. some parts remain cold, others overheat;
  • Accelerated corrosion of radiators due to prolonged contact of metal with air;
  • Circulation pump failure due to “dry friction” effect.

Tip: You can detect air accumulation by tapping on the radiator with a metal object. In the blockage area the sound will be higher and more resonant than in the part filled with water.

How to bleed air from radiators and heating pipes

The formation of an air lock in the heating system is characterized by partial cooling of radiators or sections of the water underfloor heating. Sometimes you can hear a gurgling sound in pipes and radiators, indicating where air has accumulated. Interested in 2 questions: how to remove it from there and prevent similar troubles in the future. We offer to consider the causes of blowing air in heating units in private homes, and then suggest ways to remove air bubbles from the heating network.

How to deflate a heating radiator


Air will bleed from the top of the radiator, where the cold air is located. After starting the system, the radiator in the room will be completely or partially cold. The bottom part of the battery can get warm well. However, the problem may not be blown out, so identifying the cause of the problem is the main criterion for further problem solving.

The radiator can get very hot, so you must be extremely careful when deflating. It is not superfluous to use special protection for the face and hands. Situations can be as follows:

  • With minimal heating of the batteries on the upper floors of the house, and the maximum heating of the batteries on the lower floors will indicate the lack of pressure inside the system. Hot water is simply not able to get to the upper floors.
  • If in addition to the general problem under the radiators is a regular formation of puddles, then there is a small leak. The heating is turned off, the nuts are all tightened (on the outlet valve of the radiator in the first place). However, the problem may not be solved, because the nut can rot. Such an element must be replaced.
  • A more serious problem will be indicated by very hot or very cold batteries. The problem will be in the boiler or heater, inside which sediment (sludge) may have accumulated over the years, which must be completely removed.

Wrench for the radiator

To open the air valve you need a special device. a radiator wrench.

There will be a small valve at the top that you need to find (grope). On its surface will be a small square part, by turning which you can adjust the valve. In fact, such a tool will not cost much, but for opening and closing valves, it is simply indispensable. It can be purchased at any hardware store. The size of the spanner must be chosen correctly.

A wrench from a plumber’s kit may also be suitable for turning. modern models of batteries will be equipped with adapters that allow you to perform the scrolling of the element and with a screwdriver. In most cases a needle-type Maevsky valve will be used. To turn the valve you need to put a spanner in the special thread, then slowly turn it against the clock hand.

Before you start deflating the system, you should check all the tools (a wrench and screwdriver will also be needed). Similar manipulations should be done with each radiator in the house.

Turning off the heating system

Before draining the air bubbles, you should turn off the heating system. For private houses it will not be a problem, but for apartment residents it is somewhat different. In this case you will have to wait for the spring, when the heating will be turned off by the municipal services of the city.

When you open a valve in the process of heating the radiators, the system will be further strangled. All the radiator contents must settle before the system is deflated. After the system has cooled down, you can proceed with the next steps.

Opening valves on the radiator

Outlet and inlet valves must be open at the same time (position. open).

In the photo the position of both flaps is open.

After inserting the pre-prepared key, which is located at the top of the heating radiator. Turn it slowly and counterclockwise to open the valve.

After there will be a characteristic hissing sound, which will indicate that everything is done correctly, and the air is leaving the system. When the air valve is opened, cold air masses will come out, which do not allow the collection of liquids through pipes that are connected to the common system.

Draining the water from the radiator

At the moment when the air masses leave the radiator, the water will start to ooze (drip). To avoid any discomfort, use a towel or cloth to remove drips from the surface. A plate or a bowl may also be helpful.

It is recommended to bring the vessel to the tap before you start to open it.

Wait for the water to drain out

After a while the water will stop dripping altogether. After a steady stream of liquid (without air) from the valve, you can stop manipulation, because the air from the system is completely removed (in this area).

The air valve is tightened again (clockwise). There shouldn’t be any leaks. Any liquid can be removed with a cloth, including puddles near the radiator.

Repeated manipulation

Similar operations should be repeated for all radiators in the house. Once all the air has been completely removed from one radiator, you should check the others as well, because the problem will not occur in just one area.

In order for the system to work at full capacity and without malfunctions, the system is vented once a year, with the onset of the heating season or with the arrival of the first cold weather. In this interval it is recommended to make all the necessary modifications and repairs to the heating system.

Draining air from the radiator in the presence of a boiler

If there is a boiler connected to the heating system the pressure value inside the system should be checked. After removing excess air from the system, there will be a significant reduction in overall pressure.

If this reaches a critical point, some batteries may be left without coolant (upper floors). In this case you will need to add flowing water to the system to restore the pressure indicator.

If an automated system is installed, which is responsible for the delivery of the coolant, the pressure will be about 0.8-1 bar. External intervention will not be required. If such a device has not been installed, the coolant is added manually until the pressure indicator reaches 0.8-1 bar. For a small private house, this figure is more than enough.

The higher the pressure, the higher will be delivered coolant. The capacity of the system itself and the boiler in particular will depend on this.

The first sign of air may be a lower temperature in the radiator heating in the upper part of the radiator, or become very cold.

  • Noise of heating operation, hissing or bubbling can be heard;
  • When tapping the radiator, you can hear a ringing sound;
  • if there is a lot of air in the pipes, if the coolant is heated strongly, parts of the system may even vibrate.

In these cases, it is necessary to begin removing it immediately.



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