Is a problem that prevents the system from working efficiently. The fact is that the battery in this case cannot heat up completely. prevents water from spreading throughout the radiator. Naturally, the issue needs to be resolved immediately. Otherwise, you will pay money for poor-quality heating and freeze, wrapped in a blanket.

The reason for this problem is repair or preparation of the system for the season, improper filling of pipes with water, poor sealing of elements, and the presence of air in the liquid itself. If the radiator heats very poorly, then you need to learn how to bleed air from the batteries. In principle, the procedure is not difficult, so you can do it yourself. Naturally, all actions must be done very carefully so as not to break the radiators.

First of all, you must make sure that your system is equipped with special air vents with valves on which faucets are installed. Before bleeding the batteries, decide whether you need any tools for the job. In principle, they are only required for manual air vents. In this case, for the procedure you will need a simple key or a screwdriver. WITH automatic systems everything is much simpler on the way down. However, they are very sensitive to dirt.

Before deflating the batteries, try tapping them lightly with a hammer. If you hear very ringing sound, which means there is a traffic jam in this place. Now you can start deflating. Since water will begin to drip from the pipe after it comes out, you will also need a towel or small container to collect it. Now take a wrench or other tool and open the valve. At this time, you should listen to the sounds that will be heard from the battery. The air should come out with a whistle or hiss.

Since it is quite simple to bleed air from the batteries, you should still be careful. Once the plug is gone, water will begin to ooze from the radiator. This indicates that there is no more air in the system and the valve can be closed. Do this carefully so as not to break anything. Otherwise, you cannot close the battery and you will have to call a repairman.

If, after carrying out this work, the heating does not work efficiently enough, then you will have to wash or blow out the batteries. If this procedure does not help, it means that the system is not well filled with water. You should also take into account that the air lock comes out faster if the liquid in the radiator is hot.

It should be noted that it is quite difficult to remove the problem from batteries made of aluminum. Therefore, try to bleed air regularly, even if the system heats well. If the heating is autonomous, then to deal with the plug, sometimes you have to drain water through the expansion tank.

Now you know how to bleed the air from the radiator yourself. Let your home be warm and cozy during the cold days of winter. Good luck!

The natural air content in the system creates problems during the season: cold radiators, noise, and corrosion begins over time metal pipes. To avoid uncomfortable operation and extend the service life of steel wiring and heating units, the system is freed from atmospheric plugs. Let's talk about why they occur and what ways to get rid of them!

Installing a tap on a radiator

Reasons for air concentration in the heating system

One condition for the accumulation of traffic jams is understandable - a long break in the operation of the heating system. Other reasons are as follows:

1. The home wiring calculation was done incorrectly. Slopes and bends are not taken into account. Thanks to this, even a professionally designed system will contain some air after being put into operation. is certainly formed and in some cases a rework of the entire system is required.
2. Uneven filling of the system with media. This happens due to unstable pressure in the pipeline, damage in areas outside the entrance to the house or when working intermittently. Filling of voids with atmospheric masses also occurs during heating season, if the media pressure value is low. Air vents are also used for bleeding.
3. Pipeline leakage. As a result of the operation of the heating system and, accordingly, repairs, replacement of sections with individual pipes can be carried out negligently. The absence or insufficient seal will lead to depressurization and, due to the force of pressure, the fistula will draw air into the water circuit, accumulating it in sections of the pipeline. Before removing the air lock, the pipeline is checked by soaping the prepared emulsion.
4. Air pockets appear as a result of heating the water. From school course physicists understand that when heated, the air in the heating system of a private house or apartment building expands and forms bubbles. When they burst, they release air, which immediately accumulates.
5. Absence of air intake devices or their improper operation. The air vent valve from the heating system is the first thing you should pay attention to when designing own heating Houses. Closed system With heating unit autonomous type V own home must have a similar device on the boiler or stove.

Scheme for self-removal of an air lock

The formation of traffic jams is affected by the connection of other water circuits to the heating system - boilers, heated floors. The level of location of additional devices is strikingly different from the position heating devices, making the appearance of an atmosphere inevitable. To operate these types of heating, a bypass circuit is installed with check valve, the pressure in the instrument systems will remain stable and plugging will not occur.

Removing the air lock from an aluminum and bimetallic battery

When the cause of the accumulation is determined and eliminated, the elimination of the air obstacle begins. Before bleeding air from the heating system, it is important to know how the coolant circulates - forced or natural. The method of bleeding the plug mass depends on this. So:

Natural circulation

For such a system, an expansion tank at the top point is sufficient - the supply pipeline is laid to it at an upward slope. To bleed air from the heating system, each radiator is equipped with a bleeder or a Mayevsky valve to sequentially squeeze the mass towards the previously emptied tank.

Forced circulation

In this case, the supply pipeline slopes downwards. Drain valves are installed on it, and the return flow is directed to the water drain, so that if accepted emergency measures, it was possible to bleed air from the heating radiator quickly for subsequent repairs.

Tools for bleeding air from the heating system

Numerous taps and drain valves have a reset function. The most common in private house systems are the following:

• Mayevsky crane. In the documentation it is indicated as an air needle radiator valve for heating. Required to ventilate the heating system. Consists of a brass body containing a release hole and a screw. To use it, use a special key or screwdriver to turn it counterclockwise. When air stops escaping from the system, close the valve all the way. It is imperative to prepare a container for collecting water and a rag - throw it over the tap to avoid splashing on the walls dirty water. The pump in use is temporarily switched off.
• The air vent is automatic. The principle of operation is that the float built into the body is activated - the automatic air valve itself is already located at a point in the system. When air accumulates in the pipeline, the float moves down, thereby opening relief valve and deleting it. After the pressure normalizes, the mass of water presses the float again. To prevent media leakage, the device body is equipped with a screw cap. The device is indispensable for forced circulation.

Installation of a heating system in a house

• Separator. “Advanced” air vents in the heating system. It is installed mainly in long networks with autonomous heating. Allows you to discharge not only air, but also sludge - scale, dirt, sand and clay. Consists of two parts: a common cylinder body with two outlets - upper chamber for air and the bottom for solid debris, and a filter mesh that traps air bubbles and directs them upward into the chamber. In order to bleed air from the battery, open both taps and clean the line.

For quality work home heating network, experts recommend installing several types of bleeders. For example, an automatic relief valve for heating is mounted on a boiler or furnace - there the pressure is consistently high. Radiators are equipped with Mayevsky taps each. The collector is complemented by a separator.

Determining the airy area and removing the plug: how to bleed the air

There are several ways to determine whether air is trapped in a system. The main one is the cold section of the network. In addition, the sound when tapped is louder than through pipes with normal water circulation. A characteristic noise - gurgling and hissing - will indicate the presence of air. So, when the site is determined, proceed as follows:

• An important condition: air can be expelled from the heating system only in the direction of the coolant and from a point beyond a certain area using the nearest Mayevsky valve or other type of drain.
• Next, slowly open air valve for heating, having prepared the appropriate tools, containers and rags and bleed the air.
• The control release is carried out by briefly switching on circulation pump. After which the tap is closed, and the system operates as usual.

Thus, it turns out to remove air from the heating system. Uncomplicated and independent work will take no more than an hour.

If the system still airs

It also happens that Taken measures do not work, and it was not possible to remove air from the heating system. What to do in this case:

• Try to move the accumulation of air from places located far from the bleeder valve. To do this, raise the system temperature by increasing the fuel dose. Accordingly, the pressure increases. The method is good because it allows you to remove excess air automatically through valves, an expansion tank or an air collector for the heating system. At least it will be possible to adjust the mass of air to the valve.
• Impact method. Acting with a hammer on the radiators, they create vibrations in the carrier, which move the plug. For experienced craftsmen, this method helps move a mass of air to the desired location.
• Drastically. The heating will have to be dismantled and reassembled. To get by with “less bloodshed,” they dismantle from Italian manufacturers They are good for this purpose, as they have prefabricated elements that can be neatly twisted. The radiators are also disassembled, removing accumulated sludge from them, and reassembled using sealing gaskets. The method is available only to professionals and with the permission of the service company, since it is necessary to shut off the riser if we're talking about about an apartment building.

WATCH THE VIDEO

So, having found out why the heating system is airing, it is no longer difficult to eliminate the cause and expel the accumulated masses - the process is clear.

It is important to constantly carry out preventative maintenance on your own heating model, so that future operation will avoid such unpleasant surprises that affect comfort.

Bleeding air from the battery is not difficult, the main thing is to study all the nuances!

At the beginning of the heating season, owners of private houses and residents of the upper floors of city high-rise buildings are forced to solve the difficult question of how to remove air from the heating system. Because the problem of airing disrupts the circulation of the coolant and reduces its productivity. This fact leads to poor-quality heating of the home, excessive fuel consumption, and sometimes to defrosting of the system.

Reasons for the formation of air jams

Getting rid of air in the system

Why does air appear inside a sealed heating system? This may happen due to:

1. Non-compliance with the standard for the direction of the slope and places of kinks main pipelines during installation work.
2. Incorrect filling of the entire system with water.
3. Various loose connections components and elements that facilitate the absorption of air from the external environment.
4. Incorrect operation of air vents or their absence.
5. Carrying out repair work for replacing risers, locking mechanisms, heating devices, causing air to enter the heating system
6. Using fresh water to top up the system, Cold water contains enough a large number of dissolved oxygen. As the temperature increases, its concentration in water decreases significantly. Air from the coolant is released into small bubbles that rise and are collected by an air lock in the extreme high points heating system and radiators.

What does the presence of air in the heating system lead to?

Air pockets in radiators lead to uneven heating of battery surfaces. The upper cold part of the radiators with a warm lower zone indicates that they are not completely filled with coolant. Therefore, heating radiators do not give off enough heat to the interior of the room.

When the coolant moves in the heating system, the resulting air pockets contribute to vibration of the pipes and the occurrence of specific unpleasant problems. sound effects in radiators in the form of noise, crackling or bubbling.

Air contains oxygen and carbon dioxide, promoting the decomposition of magnesium and calcium bicarbonates dissolved in water, as well as the formation of carbon dioxide. As a result of the action of elevated temperatures, hydrocarbonate compounds turn into limestone stone plaque, and carbon dioxide leads, after some time, to corrosion of the metal.

The presence of air in the heating system also causes a disruption in the operation of the main circulation pump. During normal operation of the system, the plain bearings on the pump shaft are constantly in an aqueous environment. During education air jams, they are subject to the effect of “dry friction”, and the heat generated during their operation can damage the sliding rings or put the shaft out of working condition.

Therefore, after the summer season, when starting the pump, it is necessary to remove air from the heating system.

Types of air vents and their installation locations

There are several types for venting air from the heating system. special valves in the form of manual or automatic air vents. Let's look at each of them in more detail.

Mayevsky crane

According to state system standardization, Mayevsky's manual valves are called needle radiator air valves. They are made of brass, have a reliable and simple design, are used to de-air the heating system.

Today's market offers several types of these taps, which allows each homeowner to choose the most suitable for their heating system. convenient option. The traditional classic design of this air valve has two main parts:

1. Frame.
2. Conical screw.

Mayevsky crane

Thanks to calibration, all valve elements are tightly positioned relative to each other, which ensures reliable retention of the coolant. Air from the radiator is bleed through a hole in the side area of ​​the case. Depending on the design, the Mayevsky tap opens:

• hand;
• screwdriver;
• a special ICMA key.

Starting the heating system after its installation requires its mandatory de-airing.

How to remove air using a Mayevsky manual faucet

Before carrying out air removal work, you need to prepare the appropriate tools, a rag and a container to collect water so as not to flood the floor.

1. If the autonomous heating system has a built-in circulation forced pump, it must be turned off during the air bleeding procedure.
2. Then one turn, very slowly with a screwdriver, you need to turn the tap counterclockwise. Air will begin to hiss out of the radiator.
3. The tap can be closed tightly once air stops escaping and water begins to flow out of the hole.

Automatic air vent

Automatic air vent device

An automatic air vent is a float-valve type device that independently bleeds air from the heating system. Its design is presented:

• brass body;
• float;
• articulated arm;
• exhaust valve.

At the same time, to prevent water leakage, automatic air vents are equipped with screw locking caps. To prevent external contamination Exhaust valve equipped with a spring-loaded protective cap.

The automatic air vent system works this way. In the absence of air, its float keeps the exhaust valve closed. As air accumulates in the float chamber, the float lowers, which opens the outlet valve. After the air leaves the chamber, the float is raised again by the action of the lever and closes the outlet valve.

Air separator

Air separators are installed in large autonomous heating systems. The principle of their operation is to extract air from the water, then convert it into bubbles and further remove it.

Air separators are often produced in the same housing as sludge separators. This tandem allows you to save space and additionally capture impurities:

• mud;
• sand;
• rust.

Air separators consist of a metal cylinder equipped with an air outlet on top and a valve at the bottom through which sludge is discharged. Inside the cylinder there is a special tube in which is soldered metal grid. Water from the heating system passes through this mesh. It is the mesh that creates vortex coolant flows, which contribute to braking and the rise of small air bubbles upward. Thus, the separated air exits through the air chamber. The resulting dirt particles can be removed through the bottom drain valve.

Multi-stage system

System with air removal devices

To avoid problems with the formation of air pockets, even at the design stage autonomous system heating, you need to provide one very important point. It is based on a multi-stage air exhaust system from each group of heating devices separately. In this case, they must use specific types air vents in several installation locations. For example:

• To bleed air from the boiler heat exchanger, install an automatic air vent directly on the boiler.
• Each collector has its own local air vent.
• Each radiator is equipped with its own Mayevsky manual tap.
• For risers, special air vents must be used, which must be planned for installation at the highest points.

Conclusion

The functioning of the heating system of any home directly depends on correct execution installation work and ensuring operating conditions. An important factor in this case is the lack of air in the heating system.

Usage necessary equipment to reset it, allows you to create comfortable conditions indoors and trouble-free operation of the heating system.

Before starting the heating system, it is important to properly prepare it. If a person lives in a city high-rise building, this problem It's unlikely to affect him. After all, housing office employees are responsible for carrying out such a procedure. But the owners of the private sector run the heat themselves. But even during the heating season, the batteries can heat poorly, and in some places they can even be cold. The system is probably full of air.

In any case, you need to know how to bleed air from a heating radiator in order to avoid situations associated with ineffective operation of the equipment. Why an air lock occurs, its consequences for the operation of the heating device, what methods are available to remove it - you can learn about all this by reading the article.

If there is air in the battery, nothing good will come from it. Excess air is an obstacle to the normal functioning of the system. It can also cause corrosion on the walls of the radiator.

If installed in the circuit, an air lock may also disrupt its operation. When the system is functioning correctly, the plain bearings on the shaft pumping unit are constantly in the water. And in the presence of air, a “dry friction” effect occurs, which negatively affects the sliding rings and can damage the shaft. Therefore, it is important to know how to remove air from your home heating system. Timely measures will help prevent damage to the heating network.

How can you tell if there is an air lock in the battery?

Before you bleed air from the heating system, you need to figure out why it forms 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.

An air lock can also occur under the following 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 there is air.

Such situations are not uncommon. Surely every owner of an apartment or private house has encountered a similar problem. Therefore, it is important to understand how to remove air from the heating system at home, especially since doing it yourself is not at all difficult. It should be noted that most often an air lock forms in batteries that are installed on the upper floors of the house.

Important! Sometimes the cause of a plug is a poor quality radiator.

In this case, no matter how much excess air is released, it will form again. And the reason lies in the fact that the material from which the battery is made promotes the formation of gases. There is only one way out of the situation - buy a new radiator. Therefore, it is better to immediately purchase heating devices from reputable manufacturers.

How to remove excess air from a battery?

Before you bleed air from the heating system, you need to thoroughly understand the features of this procedure and prepare everything necessary tools and materials. Let's look at how to remove air from the heating system in more detail. For this 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 be drained. And also have a couple of rags nearby in case of unexpected situations.

The algorithm for how to properly bleed air from the heating system is given below:

In addition to Mayevsky taps, automated air vents are often used for heating systems, which bleed off excess air on their own. Such automatic units are compact and reliable. But at the same time you need to be extremely careful. After all, the valve operates without supervision. And the slightest violation in the process can cause flooding of the attic or riser.

Some nuances

There are situations when craftsmen, when installing a heating system, do not install special valves to release excess air. Let's look at how to bleed air from a heating battery in this case. To work, you will need an adjustable or gas wrench. Use it to unscrew the plug. This needs to be done very slowly. Sometimes the plug won't come off. Most often this happens if. In this case, you need to apply a special lubricant to the threads and try again after some time.

When the plug is unscrewed, the same algorithm of actions is performed as with a regular tap. When the plug is screwed into place, you must remember to wrap either FUM tape or flax around the thread. This will avoid leaks and make the connection tight.

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 little, and then turn off the tap expansion tank. Usually, when the battery temperature rises, the plug comes out on its own. If such actions are unsuccessful, then the water in the circuit should be brought to a boil. In this case, the plug will definitely come out.

How often should I bleed?

Knowing how to bleed air from a heating system can prevent and solve many problems. But how often should such a procedure be carried out for preventive purposes? As a rule, this should be done at the beginning of the heating season. Twice is enough (the first time for checking, the second for control). Of course, if the system has defects or is faulty, then the number of descents may be greater.

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 vent a radiator is important and necessary. But it is better that airing of the system occurs as rarely as possible. It's better to warn this situation and install an air vent.

At the moment, air collectors for heating systems can be of two types: manual (represented by the Mayevsky crane) and float-type (or automatic). Each of the above types can be set to various places, in which there is a danger of air pockets appearing. The configuration of the Mayevsky crane is traditional. Automotive air vents can have an angular or straight design.

In order not to rack your brains about how to ventilate the heating system, it is imperative to install an air vent on each radiator.

Manual type air vent

Air vents manual type usually mounted at the end of the radiator. With their help you can easily bleed off excess air. It is enough to have only a special key. Performance similar devices small. Therefore, such an air collector for the heating system is installed only for home use.

Automatic air vent type

Regarding air vents automatic type, they operate autonomously. There is no need to unscrew or open anything. The device does everything on its own. Mount them strictly in horizontal or vertical position. But it must be said that such a valve for bleeding air from the heating system has one drawback - high sensitivity to contamination of various nature. Therefore, you will need to additionally install a filter that will clean the device from mechanical contaminants.

Important! If air has formed in the heating system, you should find out the cause of this situation. Especially if such problems have not arisen before. It is important not just to remove the airlock, but to take all measures to prevent it from appearing again. Therefore, it is necessary to check the device for leaks. Perhaps somewhere the nuts should be changed or the bolts tightened, or the joints should be sealed better. Or perhaps the air vent is installed incorrectly or the automatic air separator for heating has failed.

Bottom line

To summarize, we can say that the problem of airing the system is quite urgent. It can occur in urban high-rise buildings and in private homes. There can be many factors behind the formation of excess air. It is very important to install the real reason and know how to bleed air from a heating radiator correctly so that similar situations do not occur in the future.

An important role in the proper and efficient work Installation of special air vents also plays a role in radiators. By installing such a device, the owner of a house or apartment will be able to forget about the problem of air locks, save time and money, and also extend the service life of the entire heating system.

Apartment owners apartment buildings and everyone who has central heating has often encountered the problem of air jams in heating systems. This is reflected in the appearance of various noises, poor heating of the batteries and corrosion of metal parts.

It is typical that even from a perfectly designed and executed system central heating You need to bleed the air periodically. Its appearance inside is possible not only due to possible poor tightness of the system, but also for other reasons.

Let's look at the reasons why air jams occur:

1. In case of heating repairs.
2. In apartments it is quite difficult to de-air the pipes by immediately filling them with water.
3. This problem often occurs with heated floors, in cases where their lines are not completely horizontal.
4. The appearance of gas in water is always associated with an increase in its temperature. In systems autonomous heating After a while there is no air left, however, if the coolant is constantly renewed, the problem will appear again and again.

Problem Definition

To identify air pockets in heating you need:

• try to touch the batteries, and if part of the surface is cold or barely warm, this will mean there is air in the system;
• if the temperature in the room drops for no reason;
• if gurgling is heard in the radiator.

It is very easy to check whether the system needs bleeding by tapping a metal object on the top of the battery, and then doing the same at the bottom. Where the traffic jam occurs, the sound will be louder.

Consequences of airy heating

If the plug is not removed in time, prolonged contact with oxygen will negatively affect the metal, and it may become covered with scale and begin to deteriorate. In addition, the airiness of the system affects the circulation of water, as a result of which some places overheat and others are poorly heated.

Exist various ways for bleeding gas, and priority should be given to one or the other depending on the choice of coolant. And also, on the method of water circulation in the system: natural or forced.

As a result, an air valve is used to allow the air plug to be released from the radiator or a Mayevsky valve.

How can you bleed air?

Systems with forced circulation use a small air collector at the top for bleeding. However, it can only be vented if the supply pipe is at an angle in the direction of flow of the coolant.

In this case, the air pockets that rise with it will exit through a series of special valves.

Today, the use of manual and automatic methods is more often used to bleed air and enter water into the system. Hand held instruments(Maevsky cranes) are distinguished by their compact dimensions

It should be taken into account: You can bleed off only after the coolant has completely cooled down.

Features of automatic air vents

In order to bleed air in heating systems closed type, such as heated floors in the house, do not require human participation.

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 remove air most effectively, their design has stages, which makes it possible to remove oxygen from each group of devices.

If the pipes were installed in a private house at a slight angle in the direction of water flow, the drain mechanism allows the heating to be ventilated with a large flow of coolant and increases the pressure.

Removing air through a bleeder in aluminum, bimetallic and cast iron batteries

Benefits aluminum batteries are affordable price and excellent thermal conductivity. But aluminum is not a very good heating material due to its ability to react and release hydrogen.

When such a battery is air-filled, a Mayevsky crane will help 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.

Bimetallic radiators are another great invention. Where the internal parts touch the water, a different metal is used, and the fins are made of aluminum. In cases where a thermostat is installed on the radiator, opening it allows you to bleed the system and release oxygen.

The airing of such radiators is similar to other types.

Cast iron batteries are also vented through a Mayevsky tap or an automatic air vent, thanks to which plugs in the pipes can be removed.

Using the Mayevsky crane The device is very popular due to its simplicity. If the system gets airy, he helps to blow it out heating pipe excess air. The Mayevsky faucet 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, since in addition to releasing the air, some water will leak out. It is important to know:

Use a screwdriver to unscrew the tap and place the container. Further, if there is a cause for airing, you will hear a hissing sound, after which the air will begin to escape with drops of water through the air vents. The air will be completely deflated when a small stream of water flows through the vent. This will increase the service life of the boiler. While the system is pushing through the gas bleeder, water droplets may occur.

Using an 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 never found in heating systems.

Therefore, you need to install filters. Before this you need, which takes a lot of time. However, even this cannot guarantee you correct work

mechanism, since sometimes it will need to be cleaned. Note:

There are times when you need to shake the battery a little to force air out. You can install a regular tap at the bottom of the battery with water supply in the water supply. If you need to release air, open the tap and let the water flow. This allows it to be driven through the system and pushes the air through the air vent system.

If the heating installation sites have an incorrect 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 cause water hammer, cracks appear and the pipe bursts. Ball valves, valves, automatic air vents, and Mayevsky valves help get rid of air in the water supply system.