How to bleed air from the heating system

Air in the heating system prevents water from circulating. As a result, individual batteries or even entire risers will not heat up. In addition, due to the fact that water with air plugs in it can move along the circuit in jerks, the likelihood of water hammer increases. Therefore, it is important to understand how to deflate the air in the heating system.

Causes of air plugs formation

People usually encounter "air traffic jams" immediately after the start of the heating season. As soon as the heating in the house starts, some residents may complain about the lack of heat in the apartment. There are many reasons for this. The most common are:

• improperly designed or installed heating system (the mains are made on a slope, not all batteries are equipped with a Mayevsky valve);
• system leaks;
• disruption of the system filling with coolant;
• breakdown of the automatic air vent valve;
• installation of a "warm floor" when pipes are laid at different levels;
• the release of oxygen from water after it is heated;
• Adding a new portion of water to an existing system.

Methods of air removal

Proper planning and installation, periodic cleaning, and accurate filling with coolant will help to avoid the formation of "air plugs" in the system. But even if air does appear, you can use one of the methods described below.

Application of the expansion tank

In a system where the coolant circulates naturally, the expansion vessel helps to remove air. When installing the system, the pipe line must rise vertically to the expansion vessel.

At the top point, a container is installed where the coolant can expand when heated, ensuring the natural movement of the liquid in the circuit.

The return line is installed on a slope. This will allow the coolant to move naturally in the system.

If the system is designed correctly, the air that enters the coolant will be displaced by the hot water flow and leave the pipeline, bypassing the expansion tank.

Installation of air vents

This method is used in systems where the coolant is forced to move. An open-type expansion vessel is mounted at the top of the boiler, and a closed-type expansion vessel is mounted at the boiler inlet.

There should be no slope in the straight pipeline. To move the water inside, a pump is used in conjunction with a device that discharges air plugs. Such air vents are placed at the very top of the system and at the turns of the circuit.

Removing air from the radiator

A Mayevsky valve is a device used when it is necessary to remove air from a heating battery.

The process of venting is very simple. Simply open the tap and wait for the air plug to come out of the system. This happens with a characteristic hissing sound. The tap is closed after water flows out of the radiator hole. This procedure is used to evenly distribute heat over the surface of the battery.

Additionally installed automatic air vents will work if the pressure inside the system changes. They can be vertical and horizontal. They are installed where there is a high probability of blockage formation (loops, pipe turns).

Automatic air vents are always installed in closed heating systems. They are mounted at certain points of the circuit, which makes it possible to locally remove air at the stage of its movement to the highest point of the circuit.

Using an air separator

This device is suitable for large autonomous heating systems. Its function is to extract air from the system and then remove it. The separator usually has a separator sludge. Working together, they save space and manage impurities (rust, sand) by removing them from the system.

The separator is a metal cylinder. It has an air vent at the top and a sludge discharge valve at the bottom. A mesh is soldered to the tube, which is located in the center, and vortex water flows through it. This allows air bubbles to rise up, exiting through a special chamber. A drain valve is used to remove the filtered debris particles.

Correct filling of the system

To avoid air in the heating pipes, the system must be properly filled with water. This is done as follows:

1. All fittings are opened, except for the drain.
2. All the taps on the radiators are shut off, except for the last battery in the loop.
3. The assistant maintains a system pressure of 1 bar. This is done by using a pressurization pump or a feed line.
4. The water supply is opened to fill the main line, boiler and expansion tanks. At the same time, air will go through the air outlet and valves that are in the safety group.
5. At the same time, slowly open two taps on the radiator first from the boiler. This should be done as slowly as possible. Using the Mayevsky tap, air is released from the inside.
6. The same manipulation must be performed with all radiators.
7. Bleed the circulation pump (unscrew the pump air screw).
8. The heat generator and circulation pump start up.
9. After the water in the system begins to heat up, the radiator taps are reopened and the air is removed from them.

Preventing air from entering the system

To avoid the formation of airiness in the heating system, several devices are used:

• air separator;
• Mayevsky's crane;
• automatic air vent.

They help to avoid the formation of air locks. In addition, it is necessary:

• periodically check the system for leaks;
• follow the rules for installing the heating system and filling it with water.

Knowing what causes airiness and how to drain the air from the heating system, you can avoid disruption of its operation and other serious problems associated with the formation of air plugs.