01.02.2016

Why is the bottom of the battery cold and the top hot?

Often on construction forums people complain about heating systems - the bottom of the radiator is cold and the top is hot. It is worth noting that any radiator on top is warmer than on the bottom, but if the gap between these temperatures is too large, then most likely there is something wrong with the system. Moreover, this means that the battery produces less thermal energy than it should. After all, everyone knows that the efficiency of heating devices directly depends on the uniform heating of their surfaces.

Today we will try to figure out why this phenomenon occurs and what needs to be done about it.

How to change the battery in an apartment

Previously, we talked about how to quickly and easily replace a heating battery in an apartment with your own hands, in addition to this article, we advise you to read this information

The main reasons for this phenomenon

The problem of “cold bottom” (let’s call it that) is faced not only by those whose system is equipped with fairly old heat exchangers, but also by people who have installed bimetallic heating radiators. There are many reasons why this problem occurs, so it is difficult to immediately say why the batteries do not warm up evenly enough. Typically, each specific case should be considered individually. So, let's try to figure out the main reasons for this malfunction.

Reason #1. Normal blockage

The very first (because the most common) reason for this phenomenon is contamination of heating radiators. Here are the main reasons for the temperature decrease in the lower part of the device:

1. low-quality coolant is used;
2. air has entered the system.

It is worth noting that the working fluid can contain not only heat, but also various solid particles. For example, when the heating season begins, and centralized lines are just starting up, the quality of the working fluid is, to put it mildly, disgusting. Things are much better in the case of an individual heating circuit - contamination can penetrate into it only through an open expansion chamber.

This is all clear, but how can the temperature difference be affected by the presence of air in the system? The explanation for this is very unusual - bacteria are to blame. There is a certain variety of such microorganisms that can exist only in the presence of a sufficient amount of oxygen. Such bacteria are known as anaerobic. There is nothing wrong with them, but their waste products settle at the bottom of the heating radiator in the form of sediment.

Note! It is also worth noting that the working fluid brings sludge into the battery from almost the entire heating line, and it settles there.

Finally, another reason why the bottom of the battery is cold and the top is hot can be considered special design heat exchanger. The liquid moves in it, permanently changing the vector of its own motion. And inside the heat exchanger there is enough a large number of“secluded places” where dirt can be deposited.

Video - Cleaning the heating radiator

This reason is more or less clear, so let’s move on to the next one.

Reason #2. Problems with shut-off valves

Sometimes the reason why the temperature of the lower part of the radiator is lower than the upper part can be due to the shut-off valves. In previous articles we have already examined the design features of such reinforcement, so today we will only briefly consider a few main points. The main purpose of shut-off valves in heating circuit– adjustment, as well as complete/partial blocking of the movement of the working fluid.

The fittings can be the following mechanisms.

1. Ball valve.
2. Thermal head, which is equipped with mechanical or electronic control.
3. Cone valve.

But what does the decrease in temperature at the bottom of the radiator have to do with it, you ask? The fact is that as a result of problems with shut-off valves, the circulation of the working fluid inside the heat exchanger is disrupted. After all, the tap may simply become unusable, which is why the coolant will not flow even in its open position. This, for example, could be a failed damper or any other mechanism failure. It is also worth adding that very important role In this case, the correct installation of shut-off valves also plays a role.

Note! All taps of this type have an arrow indicating in which direction the working fluid must move in order for the heating line to function normally.

And if the tap is installed incorrectly, then one way or another the movement of the coolant will be disrupted: in this case, it will not matter whether the damper mentioned above is closed or open. We also note that for some types of shut-off valves there are requirements regarding the position in which the valve itself should be located relative to the space. For this reason, in case of problems in terms of uniform heating of heating devices, it is necessary to inspect and shut-off valves.

Thermostat for heating radiator

Previously, we talked about the types, applications and technical characteristics ah thermostats for heating radiators, in addition to this article, we advise you to read this information

Reason #3. There is not enough pressure in the system

Low pressure in the line can lead to disruptions in the circulation of the working fluid, as a result of which it may happen that the bottom of the battery is cold and the top is hot. What to do in this case? First, you should make sure that everything is normal with the pressure in the network. As you remember, not so long ago - and we are talking about the times of the Soviet Union - batteries made of cast iron were widely used. They differed in that they had fairly wide passages, therefore, in order for the working fluid to pass through the entire heat exchanger, not so much pressure was required. But modern heating radiators have a slightly different structure.

Quite often, even immediately after purchasing such batteries, people encounter a problem when the upper part has a much higher temperature. This is explained by the fact that the output and inlet pipes, as well as the labyrinth of the heat exchanger itself, have a small nominal bore. For this reason, in the line, which was originally designed for cast iron, the pressure is simply unable to overcome the resistance and “push” the working fluid through the entire heat exchanger.

In addition, the pressure in the heating line may drop for other reasons; let’s take a look at them.

1. The neighbors secretly equipped the apartment with a “warm floor” system that runs on water and is connected to centralized high-temperature heating.
2. Certain problems arose on the highway itself.
3. The same neighbors equipped their bypass with a tap.
4. Again, the neighbors significantly increased the volume of the heat exchanger, equipping it with several additional sections.
5. Finally, the same people living next door are experimenting with regulating their own heating radiators.

As you can see, often a sudden drop in pressure is associated with some actions of neighbors. As for the extended radiators, the volume of the heat exchanger in which exceeds that of the developer, and the “warm floor” system, it should be noted that all this is contrary to the law. All these manipulations lead to the fact that the pressure in the line decreases, so you shouldn’t even be surprised by the fact that the lower part of the batteries in your house will be cold.

Note! Some “experts” who visit specialized forums advise installing shut-off valves on the bypass. After this, it will be possible to adjust the degree of bypass passage by partially closing the tap so that the main flow of working fluid goes into the radiators. But doing this is strictly not recommended!

The fact is that if the relevant authorities find out about such tricks, they will force you to pay a fine and do everything as it was. By the way, if the bypass is located at a sufficiently large distance from the radiator, then the movement of the coolant in the latter may also be disrupted. And the situation will only get worse if the bypass diameter is the same as the diameter of the supply pipeline. Because of this, it can also happen that the bottom of the battery is cold and the top is hot.

Video - Bleeding air in case of cold heating appliances

Reason #4. Installation done incorrectly

Another common situation is that the battery is not connected correctly. Simply put, by mistake or for some other reason, the wrong device connection diagram was used.

Reason #5. The coolant is moving at insufficient speed

This kind of situation can be explained quite simply. If heated liquid flows at high speed through metal pipe, then as a result the pipe will be hot in all places. But if the speed of movement of the liquid is insignificant, then it will cool during circulation along the line, and the temperature of the end of the pipe will be noticeably lower. The same applies to the radiator, if it is colder from below than from above.

1. It is also worth noting that there are two main reasons for the low coolant circulation rate.
2. The cross-section of the pipeline is too narrow in a particular location.
3. If the working fluid, in principle, moves slowly along the line.

In turn, the reason for the low circulation rate (if you do not take into account the narrowed cross-section) is probably that the circulation pump has stopped working or has insufficient power for this. Moreover, this happens if there is no circulation pump at all, that is, there is a heating line with circulation of the working fluid of a natural (gravity) type. Or, alternatively, if the pipeline is already narrowed in another place.

It remains to be seen why the pipe may be narrowing. There are several possible reasons for this.

The reason why batteries in a private home do not heat up may be a number of factors. We can only consider the question in general. Eat different reasons and they are not always obvious. Sometimes such a small thing as a faulty faucet or a clogged chimney can become a stumbling block. Despite this, there are no hopeless situations, the main thing is to determine the reason why the battery in a private house does not heat, the rest is a matter of technology.

Insufficient boiler power

If the radiators in a private house do not heat well, then one of the reasons may lie in the heating boiler. In your home, you can say with almost 100% probability that the heating circuit is autonomous. So the boiler is standing.

• a gas boiler;
• electric boiler;
• solid fuel boiler;
• oil boiler.

Why do batteries heat poorly in a private home? The reason may be an incorrectly selected boiler power. That is, it does not have enough resources to heat required amount liquids. The first sign that the power has been selected incorrectly is the constant operation of the heating device, without shutdowns.

Although in this case the heat exchangers will heat up at least a little. And if the water in them is completely cold, it means that the boiler is broken or cannot turn on. Modern units have minimum pressure requirement in system. If this requirement is not met, it will not turn on. In addition, there is an automation and security system.

Let's take, for example, a gas boiler. It contains a sensor that monitors that all gases go into the chimney. It is possible that the chimney or some smoke outlet pipe is clogged. In any case, the sensor will send a command to the control unit and it will not allow the boiler to turn on.

Problems with the batteries themselves

The batteries in a private house do not heat up, what should I do? If no problems are found with the boiler and it is working correctly, then the reason why the batteries are cold should be looked for in the circuit itself.

Possible options:

• airing;
• pollution;
• insufficient pressure;
• incorrect pipe routing;
• Incorrect connection of heat exchangers.

If the batteries are cold, then you need to check all the above factors. More specifically about what to do if the batteries do not heat up we already wrote. The specificity of a private house is that all characteristics can be controlled independently.

You need to check the circuit for air pockets. There are special taps and air vents for this.

Then make sure there is no dirt in the pipes and heat exchangers. How to do it? You will have to drain water from cold radiators in a private house. What to do is known, you need to unscrew one end (bottom) of the battery and substitute a larger vessel. If black water flows, then there is nothing to think about - this is pollution. It is necessary to flush the circuit until clean water. Sometimes thick liquid flows out of radiators along with water. This is dirt collected in copious amounts.

What other reasons could there be for cold radiators in a private home? If the problem is not air or pollution, then circulation is broken. This may be due to low pressure. In general, in an autonomous circuit the coolant pressure does not exceed two atmospheres. If you have new batteries, then look at their data sheet. In modern heat exchangers, the operating pressure requirements are higher than in Soviet models. Pay attention to this.

Disruption of coolant circulation

We will separately consider the disruption of coolant circulation due to improper pipe routing and piping of heat exchangers, as a result of which the batteries are cold. In your home, you are free to choose the method of pipe routing.

• two-pipe system heating;
• single-pipe heating system.

It so happened that many people previously preferred a single-pipe heating system, also known as “Leningradka”. It was believed that it was simpler and cheaper, but in reality this is not the case. In addition, in this scheme it is very difficult to regulate the temperature of the heat exchangers as they move away from the boiler room. The farther from the boiler, the more sections there should be. Therefore, it is not uncommon that the last battery in a private house does not heat. The coolant flows through one pipe. In such a scheme there is no return.

It turns out that water enters the heat exchanger, cools there and is again drawn into the general flow. Accordingly, after each radiator the overall flow becomes colder. The difference increases with distance from the heating element. As a result, the water may reach the extreme heat exchanger almost cold.

In a two-pipe system, errors may be made in the piping:

• incorrectly installed shut-off valves;
• incorrect connection of the heat exchanger (there are three types: side, bottom, diagonal);
• The diameter of the bends is incorrectly selected.

For these reasons, circulation is disrupted and a negative result is obvious, namely a cold battery.

Every year, many consumers unsuccessfully try to resolve the issue of what to do if the radiators in the apartment do not heat well.

Need to fix the problem

If the heating season has already begun, and utility services do not want to provide heat to apartments, then you need to try to solve this problem. It also happens that in the midst of heating season the batteries remain barely warm, then consumers of central heating services begin to decide where to turn.

Experienced lawyers recommend starting to call the appropriate authorities. Utility workers must respond to problems that are expressed in completely cold radiators. In this case, the pipes may be hot. Consumer requests must also be responded to in cases where the radiator is only partially warmed up. One heating element may remain cold while all the others may be hot.

Before contacting the appropriate services, you should familiarize yourself with the temperature conditions in heated rooms prescribed in the regulatory documentation.

Application procedure

If you are faced with a problem when the batteries do not heat up, what to do is necessary to solve. Initially, you need to make a call to the dispatch company, which is responsible for heat conservation at home. This can be either a private or public organization. You must record the time and date of submission of this application, and the number of the operator who accepts it. Within a day, the submitted application must be processed, and based on its results, a specialist is sent to the site. His task will be to inspect the thermal circuit, as well as measure temperature regime indoors. Based on the information, one of the copies must remain with the owner of the apartment. The document will be reviewed by the company within a week or less. However, it is worth remembering that the established deadlines are not met in all cases. If after this the batteries do not heat up, what to do next needs to be decided. Based on the report on the previously carried out measurements, you need to draw up a claim report. A lawyer will help with this; the document should indicate that the services are provided improperly.

What to pay attention to

The claim must be drawn up in two copies, one of which is transferred to the heat supply company, and the second remains with the consumer. It must be marked with the date of dispatch, which can be done by registered mail. Utilities respond to such statements quite quickly, however, it may also happen that the batteries do not heat up. What to do needs to be decided next.

Further actions

If the complaint remains unheeded and the batteries still do not heat up, then you should find out which authorities in your city deal with utility issues. This may include the local government administration, where the department for control over public utilities is located. The consumer can also contact hotline, where the inspector will answer your questions.

If the batteries do not heat up, this article will help you decide what to do. Experts advise simultaneously involving the consumer rights protection department in the case. Quite rarely, but still sometimes it is necessary to reach the final authorities, which are the prosecutor's office and the court.

Independent solution to the problem of cold batteries

If you decide to act on your own, then you can think about what problem could lead to the low temperature of the radiator. The most common case is air locks. If the house has the latest generation of radiators, they must be equipped with a hole for air removal. It is usually installed at the top of the battery, since air accumulates there.

If you turn the tap clockwise, you will hear a characteristic hissing sound. Once water begins to seep out, the tap can be closed. In order to make sure that the air has completely escaped, even after water has seeped out, you can keep the tap half-open, since air currents can escape with the liquid.

If the radiators in the apartment do not heat well, it is, of course, important to decide what to do. Experts say that it is not worth reducing the volume of water in the radiator for a long time; it will be more effective to open the tap after a while. This will allow the water and air to restart.

Reason: incorrect connection

Improper use of the bypass, which is an adapter, can cause unsatisfactory operation of the radiator. This element is installed in front of the radiator so that the battery can be removed.

If the room temperature does not suit you, then it is quite possible that the bypass taps are open. This indicates improper water circulation. If the radiators in the house do not heat well, almost all apartment owners are trying to decide what to do. In some cases, the cause of the problem is the incorrect selection of a one- or two-pipe system. Despite the fact that the energy of the water should be sufficient for heating, preparatory stage It is necessary to carry out calculations based on the volume of the batteries and the diameter of the pipes. This is very important, as is the type of system chosen.

Reason: system clogged

It also happens that the battery stops heating due to a blockage. Over several decades, the internal surfaces of the pipes become covered with rust, which blocks access to the water supply. In this case, experts advise cleaning the radiator or replacing it.

If you are faced with a problem that is expressed in the fact that the battery in the apartment does not heat well, we have discussed what to do and where to go above. However, the whole point may also be a simple gap. And if this is so, then using a bypass you will need to shut off the flow of coolant to the radiator, which will allow you to leave the battery in working condition. If cleaning is carried out, then it is best to use the tips below.

Such work must be carried out under high pressure coolant supply. You should not expect that all the dirt will come out of the radiator if you connect the hose from water tap. It is recommended to recheck the connections before replacing the battery. If you are trying to decide what to do if the batteries do not heat up, and you find a lot of excess in the radiator, then it is recommended to perform the same cleaning steps for all other batteries in the house.

Additional reasons

Cases when the temperature in the apartment is low are not so rare. The coolant may simply not reach the last radiator along the route. This may be relevant when the system is incorrectly designed, or the diameter of the pipes does not correspond to the calculated one. Quite often the ratio of water volume to intensity and circulation is selected incorrectly.

If you still don’t know what to do if the batteries don’t heat well, then it’s also important to pay attention to whether the pump is doing its job.

The associated radiator connection scheme (Tichelman loop) is called both “very stable” and “very gentle” - it does not tolerate inaccuracies and deviations from the rules during installation. Why are there conflicting estimates? It is not uncommon for several central radiators in this system to not heat up (perform poorly). It happens that one radiator does not work, regardless of location. What's the matter?

Troubleshooting a passing circuit is very easy

If you look at the hitchhiking diagram (Tichelman loop), you can note that all radiators are connected between the supply and return lines in parallel.

Moreover, there are usually more than 10 such heating devices. When their number is smaller, a cheaper dead-end circuit is often used.

Along the way, the coolant should be distributed approximately evenly between all radiators.

But this is ideal when the hydraulic resistance of the supply and return pipelines is small, “zero”. And the hydraulic resistance of the radiators is significant and noticeable.

Then the pressure graphs in the associated circuit look approximately as shown in the figure. The point here is this: highest pressure on the outer radiators, the smallest on the central ones, but this is not at all critical - the flow through all devices is large enough for their stable operation and maximum power output.

Therefore, eliminating violations and malfunctions in the ride, first of all, involves proper installation according to the instructions.
But in practice, there are a wide variety of nuances in installations, due to which this scheme does not work. Let's take a closer look.

Saving money is not for the Tichelman loop

The main increase in the cost of the Tichelman loop is the need to lay a ring of pipelines large diameter. Typically an internal diameter of 25 mm is required. Fittings for such pipes cost a pretty penny; the design turns out to be 30 percent more expensive than the shoulder design.

If you save money and place pipes in the middle of the ring (say from 3 in the supply to 3 in the return, with 15 connected devices) with an internal diameter of 20 mm, then the hydraulic resistance of the pipelines (supply and return) compared to radiators will immediately increase and begin to affect .

The entire principle of this heating system will not be followed - the pressure on the radiators will vary too much for the circuit to work stably. At the extremes it is still large, but in the center problems will begin.

How is pressure distributed in a non-working associated circuit?

The issue with a thin pipeline will become even worse if radiators with almost zero self-resistance and a large internal cross-section are used - aluminum or cast iron. And these are not rarely used.

Then the increased resistance of the ring pipelines will noticeably affect the distribution of coolant through the radiators.

In fact, on the outer radiators the pressure drop will be large, but on devices inside the ring there will simply be no pressure - the entire flow will go through the outer ones in the ring.

The pressure graphs along the length of the pipeline in such a scheme for supply and return are parabolas that almost converge in the middle, or even completely converge (the pressure drop across the central radiators is 0), or even overlap each other.

It also happens that several radiators in the center do not heat, but for some reason the most central one works. Because in it the coolant stream is completely overturned, the movement of the liquid occurs in the opposite direction (the graphs overlap each other).

How to fix the problem

It is clear that the problem is with central radiators in passing, with a thin ring pipeline, it can be solved in an elementary way. You just need to increase the hydraulic resistance of the outer radiators, and the flow will begin to move through the central devices. Those. use balancing valves on the inlets to turn off those that are working.

Then the total resistance of the radiators relative to the pipelines increased, we returned to the classical formulation of the question, and the circuit works.

But all this is elimination emergency situation, and not a complete solution to the issue.

How should a Tichelman loop be created?

The diameter of the pipes throughout the entire ring should be optimal, so that at the end sections a low coolant velocity is ensured, within the norm, up to 0.6 m/sec.

If you take the opposite route - save on pipes and plug the outer radiators, then the overall resistance of the system simply increases. The circulation pump is loaded and it absorbs more electricity. The difference in the price of electricity offsets the savings on pipe diameters.

In addition, with this approach, you can exceed the performance characteristics of the pump, you will need a more powerful one, which is simply not a profitable action...

The associated scheme should be created by pipelines of optimal diameter.
Each radiator must have a trim valve. They are eliminated possible problems with a difference in the number of sections between devices, different lengths of leads to heating devices, different heights of their installation...

Polypropylene - harm

As you can see, the passing scheme is “very gentle” and does not respond well to any non-typical pressure distributions around the ring. They can arise due to installation circumstances - some radiator’s own resistance may be high, it’s just a different type, or it’s connected with long leads... Balancing taps will help out, with which you can set the same flow everywhere, slightly muffling devices with a large amount passing coolant.

But there is an option when nothing will help. This is the use of polypropylene pipes and the associated uncontrolled reduction in the flow area at the soldering points, and an uncontrolled increase in the hydraulic resistance of pipelines. Which is not rare.

Therefore, if “the ride doesn’t work, it was made on polypropylene...”, then the reason is clear. Or, “...a good polypropylene pipeline, they made a Tichelman loop, and it...” is simply a deception of consumers.

As a conclusion

Experienced installers have both used and continue to use the “Tichelman loop” system as an optimal system for large areas (with a number of radiators from 12 pcs).

At the same time, they try to do the following.

• Pipelines are laid under floor covering to avoid high-altitude contours of obstacles along the ring.
• Flexible pipelines are used, often metal-plastic with a good oxygen barrier.
• In the supply and return ring, only one maximum diameter is used - internal 20 mm or 25 mm.
• The most commonly used steel or bimetallic radiators With bottom connection. By the way, they have a slightly higher hydraulic resistance, which automatically balances the system.
• Each radiator is equipped with a balancing valve on the return side, and often also a thermal head on the supply side (only with an automated boiler), which is what users like.

Under such circumstances, there are no problems with a ride...

A change in the heating operating temperature can be caused by a number of internal reasons. Many of them negatively affect the efficiency of the system, increasing energy costs. In such cases, a reasonable question arises: why does the heating not heat up: radiators, batteries, pumps, systems? The first step is to find the causes of the problem.

Common heating problems

The operating principle of any heating system is the efficient transfer of thermal energy from the energy carrier (gas, solid fuel, diesel, etc.) water in pipes. The task of heating devices (radiators, radiators, pipes) is to transfer the resulting heat into the room.

And if the heating radiator does not heat, the reasons for this may lie both in the design itself and in the parameters of the system as a whole. Let's consider the common reasons for a decrease in the efficiency of a heating system:

• Low efficiency of the boiler heat exchanger. The water does not heat up to the required temperature;
• A particular radiator does not heat well. Possible reasons– incorrect installation, formation of air pockets;
• Changes in the technical characteristics of the system - an increase in hydrodynamic resistance in certain sections of the pipeline, a decrease in the bore diameter of pipes, etc. Most often, the consequence of such phenomena is that the heating circulation pump gets very hot.

In some cases, not one, but several of the listed problems arise. Often the main one is the root cause of the appearance of the following ones. Thus, the formation of an air lock affects the increase in hydrodynamic resistance, and as a result, an increased load on the circulation pump occurs.

Decorative grilles should not be installed on a heating radiator with poor heating or covered with a panel. Thus, the already low efficiency of its work will be artificially reduced.

Radiator does not heat up

Most often, problems with normal heat transfer occur in heating radiators. This is explained by their specific design - the coolant does not move through one pipe, as in a transport line, but is distributed over several.

In what cases does the heating radiator not heat? There are several factors that directly affect the correct operation of the battery.

Air locks in heating

There are several reasons for the appearance - excess temperature, water evaporation, etc. It is important that the consequence of this is the appearance of places in the line that are not filled with coolant. Most often these are heating radiators. To eliminate them, it is necessary to install a Mayevsky valve - an air valve that releases excess air from the device.

How to determine why a radiator does not heat well? The simplest method is a temperature difference on the surface. At the point where the air lock forms, it will be significantly lower, thereby preventing the normal passage of the coolant. To eliminate it, you must perform the following steps:

• Using a screwdriver or a rotary lever, the Mayevsky tap is opened;
• Add water to the system until the coolant begins to flow out of the tap along with the air;
• Shut off the water supply.

Afterwards, the surface of the radiator should heat evenly. Otherwise, repeat the procedure.

For normal heating of the radiator, you need to install an adjustable thermostat. Depending on the set temperature, it will automatically adjust the volume of coolant.

Improper installation and limescale deposits in pipes

The efficiency of its operation depends on the correct installation of the radiator. It should not be inclined relative to the plane of the floor and wall. If this condition has not been met, then the question will inevitably arise - why the heating battery does not heat.

To check the correct installation of the radiator, you can take a standard building level. If the upper plane of the battery has deviations, re-installation should be performed. It is best to use new reinforced fasteners for this.

If after this the question of why the heating radiator does not heat remains unresolved, it is recommended to flush the heating system. This problem is relevant for old pipes and radiators made of steel and cast iron. Over time inner surface a limescale layer accumulates, preventing the normal flow of coolant. There are several ways to perform the washing procedure:

• Hydraulic. A special pump is connected to the system circuit, which creates high water pressure. Under the influence of this force, the scale is broken into small fractions and retained in the pump filter;
• Chemical. Special additives act on limescale, which loses its uniformity and flakes off from the inner surface. Subsequently, hydraulic flushing is performed to remove residual debris.

Experts recommend using a comprehensive method to solve the problem in which the radiator does not heat up. After checking the correct installation, the system is flushed, and then filled correctly with the Mayevsky tap open.

If two-pipe heating system does not heat due to clogged pipes - you need to carefully choose the cleaning technology. For pipelines made of polypropylene, chemical cleaning cannot be done.

The boiler does not heat the radiators

Often, a two-pipe heating system does not heat due to the low heat transfer rate of the boiler exchange circuit. This leads to a decrease in temperature and, as a consequence, a loss of efficiency of the entire system. Not every boiler model provides an easy way to dismantle the heat exchanger. If the heating does not heat well due to the appearance of plaque on the internal elements of the boiler, you can perform flushing without this procedure. To do this you will need a pump with a filtration system. The cleaning procedure is as follows:

• Disconnecting the boiler from common system heating;
• Connection to the inlet and outlet pipes of the pump hoses;
• Filling a special cleaning liquid into the boiler heat exchanger;
• By using centrifugal pump the speed of liquid passage through the boiler increases.

After this, the radiators should not heat up poorly. Special attention should be given to the washing liquid. It should not harm the metal elements of the boiler and system. Therefore, at the end of the procedure, the entire system should be rinsed with distilled water.

To avoid the appearance of scale, before pouring water into the heating system, you need to reduce its hardness level. Usage running water not recommended as it contains large amounts of calcium and magnesium bicarbonates. They are the main source of limescale deposits not only in the boiler heat exchanger, but also in pipes and radiators.

The best way to clean the heat exchanger is to dismantle it. This way you can not only remove the entire volume of scale, but also ensure its integrity. After this procedure, the heating system should not heat poorly.

Pipelines: reasons for low heating

Failures in the heating mode are typical for a two-pipe heating system. In this case, the supply line that distributes the coolant to the radiators does not heat. Identification of the “problem” area can be done by measuring the temperature on the surface of the pipes or a thermal imager.

Natural circulation

What could cause such problems? If the heating does not heat well, the slope of the line may not be observed. This only applies to natural circulation systems. According to the standards, the slope of the pipes should be 10 mm per 1 m.p. In addition, the direction is taken into account - from the accelerating riser to the radiators. For the return pipe, the slope must be towards the boiler.

At the first stage, you need to use building level measure this indicator. If it meets the standard, but the heating radiator does not heat, there is a possibility of air pockets forming. In this case, an integrated approach is recommended, which includes the following steps:

• Measuring the angle of inclination. If necessary, change it to the required value;
• Flushing pipes to remove limescale;
• Filling the system with coolant with open Mayevsky taps on the radiators.

This technique will eliminate the low heat transfer rate of the heating system.

To improve circulation in open systems you can install a circulation pump. If it overheats, you need to install an additional one. This is often necessary for branched heating systems.

Forced coolant circulation

For a system with forced movement of water in pipes, the formation of air locks can be avoided by using an air vent installed at the top of the system. Partly it performs the functions of an open expansion tank, but does not reduce the pressure in the pipes to a critical level. Its absence is an indirect cause of poor heating of the radiator.

The specificity of closed heating systems is that it is not necessary to comply with the installation level of the pipes. However, when the critical heating level of the coolant is exceeded, steam is released, which is the main cause of air locks. Since air has a lower density than water, it will concentrate in the upper region of the pipeline sections. If the heating radiators do not heat well closed system– the reason may be a decrease in the volume of coolant in the pipes due to air resistance.

What needs to be done in this case? First of all, check the functionality of the air vents. If left idle for a long period of time, the valve may become covered limescale, which makes it impossible to open it under air pressure.

In addition to this factor, it is necessary to take into account the excess of hydraulic resistance in the system. This is why the heating battery does not heat if the initial calculation is incorrect. Therefore, before proceeding with the installation new system or modernization of the old one, the calculation part of the operational and technical parameters should be performed:

• Selection of pipes of the appropriate diameter - the larger it is, the lower the hydrodynamic resistance. However, this increases the volume of water;
• The likelihood that a two-pipe heating system will not heat is significantly less than that of a single-pipe one. Therefore, it is preferable to install radiators with parallel connections;
• Heat circulation pump heating occurs due to incorrectly selected power. It directly depends on the calculated hydrodynamic parameters.

For what reasons may the radiator not heat up? This may be due to an incorrectly selected radiator model. Each of them has a certain heat transfer rate depending on the thermal operating conditions of the system. These data are indicated in the device passport. If you choose the wrong model, then even with ideal operation of the heating system, the radiator simply will not heat up to the required temperature.

The video shows the main reasons for poor radiator heating for a single-pipe heating system: