Signs of airing
Airing leads to inefficient operation of the heating system, as a result excessive resources are spent on heating the coolant. This leads to unjustified financial expenses and can significantly affect the family budget during the cold season. Signals, if the heating system is aired, are the following signs:
- No heating of heat exchangers. Airing in the heating circuit in the form of a plug prevents the passage of the coolant through the pipes, as a result of which it does not enter the radiators or the underfloor heating pipeline. If air enters the supply pipes, the radiators and floors remain cold when the boiler is operating at full power.
- Uneven heating of radiators. If there is air in the heating radiators, one of its parts will have a lower temperature, which is easy to determine by touching the surface of the sections with your palm.
- Increased noise. The movement of the coolant in the pipeline circuit with air pockets is often accompanied by noise, which causes the movement of microbubbles.
- Vibrations. An increased air concentration in the coolant leads to an acceleration of oxidative processes due to the oxygen contained in it, accompanied by the decomposition of metals with the formation of salts and carbon dioxide. Periodic emissions of insoluble metal oxides and carbon dioxide into the coolant can cause vibration processes in pipes.
Rice. 2 Air coolers in the thermal imager
Airing the heating system causes
When solving the problem of how to remove air from the heating system, it is useful to study the reasons that cause airing, the main ones are:
- Incorrect installation. In order for water to enter the boiler with natural circulation, it is necessary to maintain a constant slope when laying pipes. Failure to comply with this condition leads to the appearance of air jams in curved sections.
- Violation of tightness. If defects appear in the pipeline of the heating circuit in the form of various types of cracks and depressurization of threaded, soldered, compression joints, air penetrates through them, leading to airing of the entire system.
- Incorrect installation of air vents. Removal of air from the heating system of a private house is usually carried out using air vents in heating radiators (Maevsky taps), on distribution manifolds for underfloor heating and at the highest point of the heating circuit. If these conditions are not met in full, the probability of airing the system increases significantly.
- Air vent malfunction. The coolant may contain decomposition products (oxidation) of metal components, expired antifreeze or metal salts. The presence of solid suspended particles in the system leads to clogging of the inlets, channels of the air valves of the air vents and makes it impossible for them to function normally.
- Failure to comply with the rules for filling the coolant. One of the reasons why the heating system in a private house is aired out is its improper preparation for operation. When filling the radiator heating circuits and the underfloor heating system with coolant, simple rules should be followed, otherwise their violation will lead to the formation of air pockets.
- After the repair work. One of the reasons why the heating system airs is air entering the pipeline after repair or preventive maintenance of individual components.For example, if the circulation pump is removed, redirecting the coolant through a parallel bypass, after installing it in its previous position, there will be a problem with the presence of air inside the housing.
- When replenishing the volume of the coolant. After pouring an additional amount of the working medium into the circuit, the likelihood of airing the pipeline increases due to the fact that the liquid contains a high percentage of dissolved air.
Rice. 3 Scheme of forced and gravity systems
Proper filling of the system with coolant
In order not to face the solution of the problem of how to bleed air in the heating system, it is important to correctly fill the circuit with coolant, for this the following rules are observed:
Filling of any system is carried out from the lowest point, for this, at the installation stage, a ball valve is placed in the pipeline
The heat carrier should be supplied at a low speed, this is especially important when filling long contours of underfloor heating. When filling a closed system, they withstand a pressure of 1 - 1.5 bar, which is controlled by a portable or built-in pressure gauge
After filling the system (in the gravitational degree it is determined by the amount of water in the expansion tank, in the forced degree by pressure), they begin to bleed air from the batteries. Before this, it is desirable to turn on the boiler and heat the water to a temperature of about 60 ° C. After airing, the coolant is added and the uniform heating of the radiators is checked again - if the result is positive, the work is stopped. If uneven heating of the batteries is detected again, the airing procedure is repeated, after which the coolant is added to the circuit.
Rice. 9 How to bleed air from the heating system using a Mayevsky tap. Examples of their use in radiators
How to bleed air from the heating system recommendations
With proper installation of the heating main, automatic air vents are installed on the pipeline and other wiring nodes that do not require manual maintenance. Therefore, the implementation of the main method, how to pump the heating system, is associated with mechanical devices. This type of device includes Mayevsky taps built into radiators - with their help, the user will have to solve the problem of how to properly ventilate the heating system.
To carry out the battery de-airing procedure, the following operations are carried out:
- Prepare a container for draining the coolant, it can be a small jar or a plastic bottle.
- With a special key or a flat screwdriver, unscrew the screw on the head of the Mayevsky valve, substituting a container under the outlet.
- Air is bled from the heating system, draining a certain amount of coolant. The presence of bubbles is determined by the sound of the escaping liquid (this is a hiss) - when the noise decreases, tighten the screw back.
- The coolant collected from all batteries is poured back into the circuit.
Sometimes it is difficult to bleed air in the heating system from radiators if they have a plug at the end instead of a valve. In this case, proceed as follows:
- Turns off the water supply to the radiator from the riser with a ball valve or otherwise.
- They remove the screw plug and replace it with a pre-purchased kit with a Mayevsky crane of the same landing size with a plug.
- The device is screwed into the radiator using rubber or linen seals, the heat exchanger is filled with water and air is released through the Mayevsky tap.
Rice. 8 Mayevsky cranes - structural device
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.
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 at times.
