Poor draft in the oven. Lack of draft in the furnace and ways to restore it. Backdraft Detection

A fireplace in your own home is the dream of any romantic. Who among us has not longed to find ourselves in a cozy chair by our own fireplace on a winter evening, blissfully absorbing the warmth spread by a living fire with our whole body?

But the smoke that fills the room and does not want to go up the chimney does not fit into this idyllic picture. Backdraft in the chimney is the name of this unpleasant phenomenon. Why does it occur and how to deal with it? We have collected information about this for you and provided it in this article.

We also paid attention to ways to check draft in a chimney and examined in detail the best options for solving the problem with draft.

Before understanding the reasons for this phenomenon, you should understand the essence of what is happening. The heating device installed in the house, together with the chimney, forms an exhaust structure.

The air pressure inside and outside the device is not the same. Because of this difference in pressure, draft arises - an aerodynamic directed flow of flue gases.

Safe and efficient operation of a heating device requires that combustion products move from the burning fuel along smoke exhaust paths. The air masses in the chimney have a lower density, as a result of which they tend to rise. They are replaced by colder outside air. This is exactly what a change in flow should ideally be.

Backdraft is not only an unpleasant, but also a dangerous phenomenon, the consequences of which can manifest as deterioration in the health of people and pets.

But sometimes a phenomenon called backdraft occurs. In this case, the smoke generated as a result of fuel combustion is directed not outside through the chimney, but into the room.

The occurrence of reverse thrust is not just an unpleasant, but also a dangerous phenomenon. The penetration of combustion products into the room leads to serious poisoning, and carbon monoxide is fatal.

The first signs of a malfunction in the movement of air masses may be not only smoke entering the room, but also a quickly smoked glass window in the firebox door. At first, the craving may just be weak, but if you don’t take action, it will reverse over time.

Sometimes another phenomenon associated with the movement of smoke occurs - the air flow changes its direction to the opposite direction for a multiple time. This is how the thrust overturns.

Causes of reverse thrust

There are several reasons for backdraft to occur. The main one can be considered mistakes made in the process. Perhaps the rules for using building materials were violated during its construction.

A problem of this kind will not arise at all if the chimney is designed in compliance with existing standards: the turn must be made at 90°, and the outlet must be positioned at an angle of 45°. Particular attention should be paid to the shape of the chimney section.

The most suitable shape is a circle. If there are corners in the design, turbulence may occur that prevents the removal of gases.

The profession of a chimney sweep, as you can see, has not yet lost its relevance, and, with the increase in the number of private cottages, it has even become even more in demand

If we compare brick and metal chimneys, the draft in the latter will always be of lower quality. The problem is that the metal heats up quite quickly, but it cools down just as quickly. And cold air, as you know, sinks.

Common reasons include the following reasons why there is no draft in your chimney:

• Chimney obstruction. It may very well be that it is simply clogged with debris or smoked as a result of long-term use. Rapid smoking can also occur if the chimney is made up of pipes of different diameters. Under no circumstances should this be done.
• Errors in calculations. Incorrectly calculated cross-section of the smoke passage. Quite often, when designing a structure by non-specialists, disproportions arise in the sizes of the elements of the device: the combustion chamber and the chimney. A powerful stove, for example, can produce a larger volume of combustion products than a narrow chimney can remove. Therefore, you need to follow it carefully.
• Design errors. The height of the smoke exhaust system is not sufficient for its effective operation. A short chimney pipe may cause insufficient pressure difference. The optimal height of the chimney pipe is five to seven meters.
• Narrowing of smoke channels. There are narrow and horizontally directed sections in the smoke exhaust paths. In such places, soot accumulates especially actively, which interferes with the free movement of smoke.
• Wind pressure. The chimney is located in the “wind backup” area. The cause of backwater could be, for example, a tall building located next to a chimney.
• Improperly organized ventilation of the room. Lack of ventilation or its improper arrangement leads to a lack of the required volume of supply air. Therefore, it is important to pay special attention in a private home.

If the roof ridge is located above the level of the chimney, then the overturning of the draft may occur when strong wind occurs.

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Option #2 – special gate valve

If problems arise with the stove, you should check the position of the damper. The gate is a damper that is designed to regulate draft. It is usually installed on the uninsulated first meter of the chimney pipe. This damper allows you to make the heating equipment operate as efficiently as possible.

This device has several functions:

• after the fuel burns out, it is used to block the pipe, which allows you to retain heat for a long time;
• as a draft regulator, the damper is used to change the cross-section of the chimney: if there is excess draft, for example, the smoke channel can be narrowed;
• with its participation, it is possible to control the quality of fuel combustion.

The material for the manufacture of the gate is usually stainless steel, the thickness of which is 1 mm. Thanks to the polished surface of the product, soot can be easily removed from it.

The temperature that such a valve can withstand does not exceed 900 °C. It is quite durable and has a low coefficient of thermal expansion.

The retractable damper should not completely block the chimney opening: 85% is the indicator that ensures safety standards for the operation of heating devices

The gate is available in two models:

• horizontal retractable plate, which is most often used in brick chimneys;
• rotary gate or throttle valve.

The throttle valve is the same plate that is mounted on a rotating axis placed inside the chimney or pipe.

The contours of the rotary damper plate follow the cross-section of the chimney, which allows it to almost completely block the pipe when the heating device is not working

Due to the simplicity of the design, it is not difficult to do it yourself. Such a homemade product in operation will be no worse than a purchased product.

Option #3 – chimney stabilizer

A product with such a telling name is otherwise called a breaker. This is a mechanism that automatically and dosedly supplies air into the chimney, allowing you to optimize the operation of the heating system without involving a person in it. To prevent excess pressure from being created, the breaker is equipped with a safety valve.

Stainless steel is used to produce a chimney draft stabilizer. The maximum temperature this device can withstand is 500°C.

The draft stabilizer installed on the chimney must be adjusted in accordance with the recommendations that you will find in the operating manual for your heating boiler

The essence of the stabilizer is that it automatically adds cold air directly into the chimney. At the same time, the temperature and speed of gas movement inside the pipe decrease. As a result, the efficiency of using burned fuel increases without any changes in the operating mode of the heating device itself.

The breaker is usually installed on the chimney pipe. In this case, the distance from it to the heating device (boiler) must be at least 0.5 meters. The breaker should only be located indoors.

Since its operation is based on a system of precisely balanced weights, the influence of natural factors on the operation of this device must be excluded.

Setting up the stabilizer can be considered complete when the minimum draft value is set on its regulator in accordance with the data specified in the operating instructions for your heating boiler. You should set either the exact parameter or a division higher than the recommended one.

In addition to using the listed devices, to prevent backdraft, you can lengthen the chimney pipe, straightening it as much as possible. Bends and sharp turns of the shaft increase cavitation when gases are vented out.

Conclusions and useful video on the topic

If a problem with draft does not manifest itself in clouds of smoke throughout all rooms, this does not mean that it does not exist. A device will help you identify it; you can familiarize yourself with its structure by watching this video.

This product may save your life by calling attention to the problem in time, since carbon monoxide, for example, has neither color nor odor.

This video contains information about the appearance of the TsAGI deflector and its components. You can see how to build this device yourself.

If you feel strong enough to make your own traction stabilizer, then this video will become a real guide to action for you.

Any device operating in your home must work properly and not create a threat to the life and health of people during its operation. Heating in this sense is no different from other useful devices. A deflector, gate and stabilizer will help make its operation stable and efficient.

Do you have a problem with chimney draft and are you trying to solve it on your own? Did you find the answers after reading our article? Or do you still have unresolved questions that we missed? Feel free to ask them in the comments section, and we will try to clarify these points.

An unpleasant burning smell, smoke in the room, poor combustion of wood - all these are consequences of reverse draft in the chimney. This is a problem faced by many owners of fireplaces, stoves, solid fuel boilers and other wood-burning heating devices.

1. The chimney is clogged with soot

Perhaps this is the most common and main reason for deterioration in traction.

During the burning of wood, soot is formed. It consists of particles of combustion products that stick together and settle on the inner walls of the chimney, which leads to a narrowing of its diameter. As a result, air movement becomes difficult.

Therefore, soot must be removed regularly. This way you will not only improve traction, but also increase the operating efficiency and fire safety of the heating device. To make the chimney walls less contaminated with soot, you can use fuel wood briquettes, which contain less moisture and other harmful impurities.

2. Insufficient air flow

When burning wood, the air needs to move from bottom to top. That is, from the room into the chimney and out into the street. To do this, in the room where the heating device is installed, there must be an air flow - draft.

If all the windows are closed, if the ventilation is not working properly, then the smoke begins to move in the opposite direction - from the chimney into the room. That is, reverse thrust occurs.

The easiest way to solve this problem is to create proper air movement in the room. For example, open a window before lighting a fire and close it 10-15 minutes after the flame has flared up.

3. Cold outside air pressure

The draft in the chimney may worsen due to a decrease in outside temperature. Since cold air is heavier than warm air, it sinks down and “presses” inside the pipe. This problem especially often manifests itself in the presence of the previous two - lack of air flow and a clogged chimney. It strengthens their influence.

Therefore, the solution is: insulating the chimney, removing soot and creating an air flow.

Often a canopy is installed on chimneys, which can prevent smoke from escaping from the chimney. As a result, an air “plug” of smoke is formed and draft deteriorates.

In such cases, the visor should be replaced with a higher one or removed.

5. Incorrect chimney design

Backdraft can occur as a result of improper chimney design: narrow diameter, too high a height, or the presence of a large number of bends or narrowings.

To eliminate problems of this kind, you will have to rebuild the chimney, which will entail a significant investment of time, effort and money.

6. Brick collapse

Due to the constant heating and cooling process of a brick chimney, it can collapse. Bricks will fall off, fall down and clog the chimney.

To avoid such a situation, the chimney must be insulated. This will also solve the problem with cold air pressure.

CONCLUSIONS

So, how to increase draft in a chimney? Here are a few simple steps that don't require much time or money:

• Clean the chimney of soot. This is the first thing to do. You can do this yourself, with minimal investment of time, effort and money.
• Provide air flow. Open the window for 5-10 minutes before lighting the fire. This will create the correct movement of air in the room from bottom to top. The window can be closed after the fire has burned out.
• Insulate the chimney if it is not insulated. This will reduce the influence of cold air and also extend the life of the chimney.

Eco-friendly homestead: Poor draft in the stove, smoke goes into the room and not into the chimney, soot quickly accumulates in the chimney, the flame flares up and goes out quickly - everyone who has a stove has encountered these problems. Is it possible to solve these problems yourself, without resorting to the help of professionals? Let’s figure it out together.

There can be several reasons for poor traction. When the device is not used for its intended purpose for a long time, cold air accumulates in the chimney, which does not allow the heat that comes from the stove to escape outside. Therefore, smoke accumulates in the room in the first minutes after ignition.

The situation can be corrected, but you will have to make an effort. First of all, it is necessary to remove cold air from the chimney, which forms an air lock. See if there is a hole right under the pipe through which the chimney can be cleaned. If there is one, you should open it and put in it some lighted paper twisted into a rope. Thanks to this simple action, the pipe will warm up and the cold air will gradually come out of it.

If there is no cleaning hole, you can try pushing paper through the hole where the slide is located. The oven itself will tell you how long this procedure should take. When the traction becomes good, we proceed to the second stage. It involves heating the chimney. To do this, curled and lit paper is placed in the firebox, as far away from you as possible and closer to the furnace heat. It should burn to warm the air throughout the chimney. If everything is done correctly, the stove can be lit without fear of smoke entering the room.

How to light a stove correctly

Before putting wood or other types of fuel into the firebox, you should clean it thoroughly. You need to remove ash not only from the firebox, but also from the ash pit. It must be clean between the grate bars, otherwise air will not flow into the firebox. Then you should lay in the firewood, and at once as much as is necessary for the stove to light up normally.

Experts recommend using logs of the same type for kindling. Their thickness should be such that the fire starts on the wood. It is very important to leave gaps between the firewood when laying. It is best to place wood chips, splinters and small firewood in the very bottom layer, which will quickly start the fire and transfer the flame to thicker logs.

There are two ways to stack woodpiles: in a row or in a cage. Gaps are necessary so that the firewood flares up at the same time. Another feature that should be remembered: the firewood must be laid in an even layer on the grate.

It is important that the fuel compartment is completely filled with logs, but the firewood should not reach the top; you need to leave a space where the highest air temperature is created. Thanks to this, the stove warms up quickly, and wood or other fuel burns almost completely. To safely light the stove, you must first open all doors, dampers, and valves of the structure. When the firewood is well lit, the firebox door is closed and the ash pan is left slightly open for air flow.

And finally, one more good piece of advice. If you have not fired the stove for a long time and want to get as much heat as possible from the device, which will warm you for a long time, it is best to heat the structure twice. The break between fires should be approximately 4 hours. In this case, greater efficiency will be achieved than when organizing continuous combustion, when whole armfuls of firewood are burned, and the result is not satisfactory. published

How nice it is to warm up on a cold winter evening by a warm stove or fireplace! The crackling of logs coming from the firebox has a very relaxing effect on the human body. The heart becomes warm and light.

What is smoke draft?

A person who has recently become the owner of his own home with stove heating is wondering what to do if there is backdraft in the chimney. This phenomenon is noticed immediately and occurs in the chimney area. Formed as a result of heating and chimney ducts not working properly. As it turns out, there are a lot of different factors that lead to this phenomenon. In order to choose a way to combat this problem, it is necessary to understand this issue as thoroughly as possible.

Backdraft is a flow of flue gases that does not tend upward, as any stream of warm air should, but into the room where the stove is located. The main reason for this phenomenon can rightfully be considered the difference between the pressure created in the firebox and the pressure outside. As a result, the flow is directed along the path of least resistance.

The formation of reverse draft occurs when the flue gases, which are actually formed during fuel combustion, are not directed through the pipe to the street, but move downward, that is, into the house. Also, in parallel with the concept of reverse thrust, there is such a phenomenon as its overturning. At the same time, smoke also rushes into the room in a stream. So, let’s try to answer the question of what backdraft in a chimney is, what to do, and how to restore the system’s functionality.

Traction standards

A person cannot help but be upset that reverse thrust occurs. What to do can be decided only by carefully understanding the origins of the problem. It is very important that the chimney channel operates in full mode. If any failure occurs, the fuel does not burn completely. This, in turn, leads to the accumulation of smoke in the firebox area. It reaches a certain volume and after that it begins to release into the free space that is the room. This does not fit into any fire safety standards and has a negative impact on human health.

There is also nothing good in the fact that the draft is excessive, since this leads to excessive heat losses. Due to this, the oven becomes very hot, which can cause its deformation and even a fire. Therefore, you need to carefully monitor the condition of the entire heating system. The average pressure in the chimney area should be 10-20 Pa.

Backdraft in a chimney: what to do?

Reasons for appearance:

• Low chimney pipe. This results in a small difference in pressure. As a result, very poor smoke draft or its complete absence.
• Incorrect installation design. This is an incorrect relationship between such parts of the heating system as the combustion chamber, the height, and the diameter of the chimney duct.
• A wind surge caused by a taller building nearby.
• Poor ventilation and insufficient supply air.
• Atmospheric indicators.
• If the roof ridge is located above the level of the external chimney, then in strong winds the draft may overturn.
• Pipe clogging with a wide variety of debris.

Only when it is known what causes the backdraft in the chimney, what to do and how to improve the operation of the stove will be immediately clear.

Backdraft detection

In order to answer questions about how strong the backdraft is in the chimney, what to do, what methods of combating are suitable, it is necessary to initially determine the fact of its presence. You can determine that there is reverse draft in the area of ​​the chimney duct using a special device - an anemometer. This type of diagnosis is the most accessible. It should be noted that determining the presence of reverse draft is possible only if at the time of testing there is sufficient wind flow, the indicator of which exceeds 1 m/s. If its value is lower, then determination is impossible. It is very bad when the readings indicate that there is backdraft in the chimney. What should I do to fix it?

Since it is not always possible to use special devices, in this case proven folk methods will come to the rescue. First of all, determination is possible using simple visual perception. If it is noticed that there is no smoke in the room, this is direct evidence that there is direct draft. Special attention should be paid to the color of the fire. If the flame is predominantly white, we can talk about high draft. In addition to the color, this is indicated by the sound that comes from the firebox. It's more like a hum. The orange color of the flame indicates that there is no draft. The correct level of draft is characterized by a golden color of fire.

When determining traction, the most ordinary matches or a sheet of paper will come to the rescue. If at the moment of burning a match or a sheet of paper there is a deflection of the flame, then this indicates that there is draft.

In the case when you need to determine the absence of smoke draft, you just need to look into the middle of the firebox. If there is a lot of smoke in the cavity, this means there is no draft. It is necessary to treat this phenomenon with a high degree of responsibility, since this can lead to gases beginning to escape from the firebox and accumulate in the room. If it is discovered that there is backdraft in the chimney, what to do should be decided as quickly as possible.

Installing the deflector

If you managed to figure out the main reasons, and it turned out that reverse draft occurs as a result of deviations in air flows, the deflector will decide what to do about it. This is a special device whose operation is based on the aerodynamic effect. It reduces the pressure level as quickly as possible when certain obstacles arise in the path of air flow. The high quality of operation of this device is noted in strong winds.

Stabilizer installation

The stabilizer is installed in the cavity of the smoke exhaust duct. There is a special hole at the bottom of the case, thanks to which free air circulation occurs. Due to the fact that the stabilizer has a special design shape, it has the ability to completely control the air pressure in the pipe. The operation of this device is carried out in conjunction with a special sensor that monitors the temperature of the exhaust combustion products. If the draft suddenly deteriorates, and as a result, smoke accumulates in the pipe, which leads to heating of its walls, the sensor immediately triggers.

Using a Rotary Turbine

A rotary turbine will help if there is backdraft in the chimney. She will help you decide what to do and how to fix it. The work is carried out by using the wind energy generated in the turbine. It is installed directly at the very top of the chimney pipe. Due to the fact that the turbine constantly rotates in a certain direction, it is in the area of ​​the smoke channel. But this is not the only function that this device performs. It prevents debris from getting inside. Despite such significant positive features, the rotary pipe has its own specific drawback. The thing is that it continues to work continuously even during the end of the heating season, that is, in the summer. This, in turn, leads to a strong increase in the draft level in the chimney area.

What are the dangers of improper operation of the heating system?

Good and safe operation of the heating system directly depends on the level of smoke draft. If the very first signs of a problem appear, you need to check, and if any malfunctions are detected, you need to eliminate them as quickly as possible. In some cases, poor draft leads to carbon monoxide entering the room. As you know, it is very dangerous to human health and in some cases can even lead to death. It is quite possible to fix most existing faults with your own hands. If you do not have experience or skills, it is better to seek help from specialists in this field, who will effectively complete all the necessary work in the shortest possible time.

Temporary backdraft

In some cases, backdraft is not a permanent phenomenon, but rather a temporary one. We answered the question: “If backdraft occurs in the chimney, what should I do?” Restoring the normal process will take very little time. Often the main reason is cooling of the stove and chimney. The fact is that during this period of time, cold air accumulates in the cavity of the firebox, which is heavier than heated air, and it is this that interferes with normal draft. As a rule, smoke can completely fill a room in a short time. In such cases, a draft stabilizer installed in the chimney cavity will help get out of this situation.

Having a heating boiler without automatic ignition, a fireplace or a stove, you will have to learn the profession of a stoker. You will need to know how best to place fuel, how best to light it, and much more. One of the necessary knowledge is what chimney draft is, what it depends on and how to make sure there are no problems with it. It's not as simple as it seems. There are many nuances.

What is chimney draft?

To understand what draft is in a stove chimney, how it is formed and what it depends on, we need to remember the laws of physics:

• Warmer air weighs less and rises, while colder air weighs less and sinks.
• Gaseous substances move from an area of ​​higher pressure to an area of ​​lower pressure.
• At the surface of the earth the pressure is higher, the higher we rise, the lower the pressure.

Based on the operation of these laws, smoke removal is arranged in heating boilers and furnaces: due to the difference in pressure/temperature, smoke and combustion products are discharged outside the room through the chimney. During normal operation, smoke moves from bottom to top, leaving the room through the chimney.

So, what is chimney draft: this is the movement of air along the chimney - from a lower point (indoors) to a higher one (outside above the roof). Essentially, air is “pulled” from the furnace/boiler into a zone of lower pressure (at a height of 5 meters above the “boiler level” the pressure is noticeably lower). Hence the common name for this phenomenon is “traction”.

During normal operation of a boiler or furnace, smoke “goes” into the chimney. At the initial stage, while the stove is not yet heated and the fuel is not burning, air flows into the chimney due to the pressure difference that is formed due to the height of the pipe. Later, when the temperature in the furnace rises, the air heats up and becomes lighter, and the speed of gas movement through the pipe increases. The traction “works” normally.

But there is draft in the chimney if there is an influx of fresh air in the room - due to ventilation holes or cracks in the windows - depending on who you are. If sealed double-glazed windows are installed and there are no supply openings/ventilators leading to the street (or at least to a room with air flow), then there will be no draft. There is no air movement and everything does not work. The smoke escapes weakly/poorly or generally into the furnace room. There is simply no draft in the chimney - no air movement from bottom to top. The solution to the problem is to make inlet holes and everything should work. In general, there are quite a few reasons why there is no traction, but this is one of the main ones.

How to check

You can check the presence and “quality” of draft in the chimney very simply: using a lit candle or match or a sheet/strip of paper. It is easier to determine with a sheet if the draft in the ventilation duct is checked, with a flame - when checking the operability of the chimney.

The easiest way to check for draft in a chimney is to hold a burning match or candle

First, let's figure out how to check the draft in the ventilation duct. Take a piece of paper and bring it to the opening of the exhaust ventilation duct. If there is a grate, the sheet is attracted to it and “sticks” and is not easy to tear off. In this case, the draft in the ventilation duct is considered normal. If it is easily removed, the traction is insufficient; if it does not stick at all (falls), there is practically no air movement.

You can also check the traction using a strip of paper - if there is traction, the strip should be pulled inward

When checking the chimney draft, the situation is similar, only we use the flame of a candle or match (not as convenient as with a candle). We bring a lit candle or match to the open door of the boiler (solid fuel, liquid fuel) or to the slot for igniting a gas one. Observe the behavior of the flame:

In case of insufficient draft or its complete absence, it is necessary to take urgent measures to normalize smoke removal. Otherwise, you can get burned - smoke and carbon monoxide (CO) will go into the room, which will lead to poisoning. Automated gas boilers, if there is insufficient draft or its complete absence, will not work at all. They have built-in sensors and if the air movement through the chimney is insufficient, the gas is shut off. Disabling the sensor is very dangerous. It’s better to figure it out and improve the draft in the chimney.

What to do if there is reverse draft in the chimney

Sometimes while the stove/boiler is operating, smoke begins to enter the room. In this case, they talk about the occurrence of “reverse thrust” or its “overturning”. A very unpleasant and, in some cases, dangerous phenomenon. There are several reasons, as well as solutions.

Draft overturning (reverse draft) usually occurs when the chimney height is insufficient

No air flow

In the struggle to reduce heating costs, home and apartment owners often make the mistake of sealing the room. Plastic or metal-plastic windows with double-glazed windows are installed, and all cracks and crevices are carefully sealed. There are no supply ventilation holes at all. In this case, heating boilers will practically not work. While the pressure in the room is higher, air/combustion products are still removed from the room. This happens through the chimney, the hood above the kitchen stove. There is no inflow, the pressure in the room decreases. When the pressure outside becomes higher than inside, smoke enters the room. They say that “the draft has capsized.”

A prerequisite for the presence of traction is the presence of air flow

In this case, getting rid of reverse draft is simple - providing air flow. The easiest way is to open a window or window. The smoke should go up the chimney, the situation will return to normal. But of course, this is not a solution to the problem. To get rid of draft overturning completely, it is necessary to make fresh ventilation.

Low pipe

When installing a chimney, it is necessary to follow the recommendations of the boiler equipment manufacturer. They are prescribed in the operating instructions. There is such a point as the minimum chimney height. Under any conditions, your chimney cannot be lower than the value specified in this paragraph.

But there is one more “general” rule: the pipe above the roof ridge must rise at least 50 centimeters. In most cases, this pipe height is sufficient for good traction. If the pipe is not high enough, when there is a gust of wind, the air flow swirls and enters the pipe. Since it is much colder than the air in the chimney, it rushes down, carrying smoke into the room with it. The solution to the problem in this case is to extend the pipe to the required height.

Insufficient insulation

(metal single-walled or asbestos too) can cause the draft in the chimney to tip over in winter during frosts. Even if your pipe is insulated (sandwich type), with strong gusts of wind there is a sharp removal of heat, which is why the smoke cools sharply and rushes down.

Solid fuel boilers usually cope with short-term gusts - the temperature of their gases is higher and it is not so easy to cool them down. But gas ones (especially low-temperature condensing ones) often turn off - the reverse draft sensor is triggered, and the gas supply stops.

The solution to the problem in this case is additional insulation (“Isover”, in colder regions with additional brick lining).

Large room with drafts

This problem often occurs in cottages with a fireplace. A fireplace is usually made in the living room - a large and spacious room with high ceilings. If there are drafts in the room, it is quite possible that the draft will overturn.

The second case is a house under construction. Having put up the box and installed the stove, the owners continue to carry out finishing work. Doors are often only entrance doors. If in such a situation the draft in the chimney overturns, install doors to the furnace room (or to the room where the stove is located). At the same time, do not forget that there must be an air flow (supply ventilation ducts). This should solve the problem.

Incorrect chimney arrangement

Often the cause of unstable draft is improper chimney design. For normal operation of the boiler/sauna or heating stove/stove, it is necessary to raise the chimney from the roof by at least 50 cm. Then it can be turned in the desired direction, making a horizontal section (but not with a reverse slope). This vertical section is necessary to “accelerate” the flue gases. In it, they pick up speed and then overcome horizontal sections without problems (their total length is no more than 3 meters).

An important point: the accelerating vertical section of the chimney is best made from a pipe with smooth walls. Even if you have a boiler with a low-temperature exhaust, do not use a corrugated pipe. Due to the unevenness of the walls, “acceleration” is slowed down, and periodic overturning of the thrust is possible.

Another reason for poor draft in the chimney is its small cross-section. Sometimes, to save money, they install a chimney with a diameter less than the nominal one. The solution is obvious - increasing the cross-section of the chimney. If the fuel burns quickly and there is little heat, dampers are installed on the pipe to regulate (reduce) the draft. But installing a pipe of a smaller diameter is not something you should do for sure.

Blockages and soot

Sometimes the draft in the chimney “disappears”. Most often the cause is a clogged smoke duct. It could be soot, some foreign object, a bird caught in it, etc. It can be treated simply by cleaning the chimney.

First you need to inspect the pipe, checking if there are any foreign objects in it, and then start cleaning the pipe from soot. There are many methods - from traditional mechanical cleaning using special brushes, to chemical cleaning - special logs or liquids that are used to heat the stove/boiler. There are also folk methods - heating with aspen wood (can be dangerous if there is a large amount of soot), burning potato peelings (a longer method of cleaning a chimney from soot, but also safer).

Ways to improve chimney draft

In some cases, everything has been checked, all defects have been eliminated, but the draft in the chimney is insufficient, or periodically overturns. Most often, this is observed in areas with complex terrain, with unstable winds, if large trees grow nearby or taller buildings are located nearby. Air flows are reflected from a nearby obstacle and enter the chimney. For such cases, there are devices to increase chimney draft, you can: