Backdraft in the chimney, what to do, why it occurs and occurs

Often, owners of private houses and bathhouses are faced with a rather serious problem - smoke from the heating furnace.

There are a huge number of reasons for this phenomenon - from violations of the technology of constructing the device to a decrease in smoke draft. Smoke may be temporary or permanent, but in any case requires prompt elimination. First of all, it is necessary to determine the probable reasons why the stove smokes in the house and bathhouse, and choose effective ways to eliminate them.

Where to start checking your furnace

Smoke comes out of the house, and you need to start checking from the roof - from the chimney.
If the draft was good, but suddenly stopped, the cause may be an object that blocked the pipe. This happens especially often if there is no cap over the chimney and there are tall trees nearby. Any object can mechanically narrow the chimney channel: a nest made by birds, a brick falling out of the chimney, an accumulation of branches, debris. If there is no cap, the draft also disappears during strong winds. The air mass creates a turbulence in the pipe and blocks the path of smoke. It comes back and exits through the latches and doors. In calm weather there is no smoke in the house, and from this sign you can already understand its cause.

Wind

A temporary cause of backdraft can be the wind, the direction and strength of which “drives” the smoke back into the chimney. Tall trees or buildings located near the house can contribute to this.

Install an umbrella or deflector on the top edge of the pipe. These devices significantly improve draft, protect from rain and prevent the wind from blowing smoke back into the chimney.

To date, many deflector designs have been developed. There are rotating models that are themselves installed by the force of the wind so that there is no interference with the smoke.

Many people are interested in the question: how to line an iron stove with bricks? Read useful information in our article. For information on self-repair of Ariston water heaters, see here.

Read about winter kits for air conditioners at this link.

Causes of smoke in new heating stoves

What to do if a newly installed stove smokes? Often the cause of smoke is structural inconsistencies, non-compliance with the technology of the masonry process, insufficient ventilation, and the absence of a distribution box.

Incorrect chimney height

The main reason for smoke in new stoves is a miscalculation of the height of the chimney pipe. Heating equipment for a Russian bathhouse and a private house must meet the following parameters:

The size of the stove pipe opening depending on the type of fuel: 140×140 mm (coal) and 140×270 mm (peat briquettes, firewood).
The height of the chimney above the roof is 75 cm, the elevation above the ridge is 50 cm. If the ridge is more than 1.5 meters away from the chimney, then the chimney can be of a similar height.

If the height of the chimney is not sufficient to prevent smoke, then you can increase it yourself.

Why does the stove smoke when the door is opened during the lighting process? A similar problem arises when there are serious design miscalculations: incorrect cross-section of the exhaust pipe, low location of the inlet channel, unswept chimney. To eliminate the shortcomings, a major overhaul of the heating equipment will be required.

Violation of stove and well construction technology

The required clearance of the chimney pipe ensures quick and safe removal of fuel combustion products. The minimum pipe diameter for a house is 15 cm, for a bathhouse – 10 cm. The height of the pipe and its installation location on the roof must correspond to the chosen design of the heating stove.

In addition, the inlet to the first well (in the combustion chamber) must be located no lower than the top of the door, otherwise this may lead to smoke every time the stove is lit. The shortcomings can only be corrected by rebuilding the furnace structure.

When assembling the chimney, you should avoid using elements of different sections, which can be the main cause of smoke in the stove. The best option is a round pipe. Rectangular smoke exhaust channels can create unnecessary air vortices and increase soot deposition.

Poor ventilation

Another reason why a new furnace starts to smoke is poor ventilation. As a rule, when installing a forced-type ventilation system, building owners provide exhaust hood only in functional rooms - a sanitary unit, a kitchen or a dressing room. However, a separate smoke channel must also be equipped in rooms where normal movement of air masses is required: in the steam room and washing room.

No distribution box

If there are two heating stoves installed in a building, for which a common smoke exhaust system is provided, then smoke occurs as a result of the absence of a distribution box.

To eliminate this problem, it is enough to make a distribution box with two separate channels or operate the furnaces alternately.

The distribution box is a special brick partition located inside the common chimney.

Reasons for the brick stove

We have identified the main common cases caused by shortcomings in the heat generator and/or the combustion products exhaust system combined with it. All of them, one way or another, lead to worsening traction. But almost every situation can be corrected either on your own or by calling cleaning and repair specialists.

1.1 No distribution box

The problem arises when two systems are turned on in the house at the same time, and combustion products are discharged through one common channel, in which there is no dividing partition. As a result of this, the gases move towards each other, collide, create turbulence, and reverse draft enters one of the fireboxes.

It is simple to prevent or even correct such an unpleasant phenomenon: just install a distribution box under the chimney. It will prevent the flows from mixing, directing each one strictly up the channel.

1.2 Brick collapse

Any material wears out over time - under the influence of temperature changes and condensation, due to the accumulation of soot and periodic blockages. Artificial stone is no exception: it collapses, and pores and microcracks form on the surface, which at first simply trap gas masses, and then, at an advanced stage, lead to collapse.

Damaged areas, except in the most difficult cases, can be restored as follows:

remove worn-out building materials and clean problem surfaces;
apply a solution of clay and sand to the treated areas;
lay a brick (preferably heat-resistant) and plaster the surface.

Now you know what to do when the stove in the house smokes due to a collapse, but it is much more correct to avoid even partial destruction of the channel for the release of combustion products. Timely and regular prevention is simply necessary, and at the end of the review we will definitely look at how to carry it out.

1.3 Defects in the door and combustion chamber

There can be several of them at once:

The heat generator does not close tightly, but with a gap. This deficiency needs to be corrected. As a temporary measure, you can block the hole through which smoke enters the room with a piece of brick, and cover this place with clay. Although it would be better to simply choose a new damper that will not have any cracks.
The vent is too short for the fuel used (if it is firewood, dry bushes or other plants, hay, straw). In this case, it is necessary to lengthen the ash pit, if possible, even if it is necessary to shift part of the masonry.
The firebox is designed with errors: there are gaps in the fan area of the frame or the channel outlet begins below or at the level of the door. In the first situation, it is enough to simply close the draft sources, in the second, you will have to install a brick jumper on the back wall of the chamber.

1.4 Errors in laying a well

It is typical that the problem appears only when the firebox door is open (and if it is closed, everything is in order). This is due to an incorrect design that changes the natural path of gas flow. As a result, there is enough traction in a confined space, but in any other cases it is no longer enough.

To prevent combustion products from ending up in the room, you will have to relocate the well - all defects will be physically eliminated.

1.5 Presence of cracks in a brick kiln

They form over time as a result of wear and tear of the brickwork material. They worsen the combustion of fuel; if they appear in the upper part of the chimney, then the wind blows into them, if in the lower part, the waste combustion products flow from them back into the room. Over the years, they expand, further reduce traction, and provoke brick collapse.

Therefore, the cracks need to be sealed - with a solution of sand and clay, taken in a ratio of 1 to 1 and diluted with water to a thick plastic mass. After you prepare it, do the following:

clean the problem areas, removing not only the settled dust, but also the whitewash layer;
moisten the treated areas with water and apply a cement primer;
fill the gaps with mortar so that they are level with the walls;
walk over the restored surface with finishing plaster.

According to this scheme, first the internal and then the external cracks are covered. By the way, if they appear on tiles, it is better to prepare another solution - from plaster and chalk, it will bind more strongly.

Soot adhesion

The most common source of deterioration in draft is the adhesion of soot on the walls of the chimney. The internal diameter of the pipe becomes so narrow that smoke, accumulating, exits through any cracks in the unit body. The degree of soot adhesion does not depend on the location of the stove: in a bathhouse or in a house. Incorrect operation and certain types of burned wood contribute more to its formation. The first factor is insufficient, and the second is the burning of coniferous logs. The only way to repair in this case is to clean the chimney.

How to clean a chimney?

The mechanical cleaning method requires special devices:

ruff, cable, weight.

First, a weight attached to a cable is lowered into the chimney. This way you can find an obstacle or a place where the pipe has narrowed. If it is necessary to push through any object that has blocked the channel, the weight is thrown down with force. At the next stage, the pipe is cleaned with a brush. It has the shape of a square or round brush, its dimensions should be slightly larger than the pipe hole. Using down/up movements, the chimney is cleared of soot and accumulated small debris.

Reason 7 - no junction box

If there are two stoves that use one common chimney, then the smoking in this situation is probably due to the fact that there is no distribution box in the chimney.

This cause can be eliminated in two ways: by constructing a distribution box or by using only one oven at a time. How the distribution box should be installed is shown in the figure:

Installation of a distribution box in a chimney common to two stoves

Checking the draft quality in the chimney pipe

To determine further measures to eliminate smoke from the stove, it is necessary to check the quality of draft in the smoke exhaust system. Verification is carried out in one of the following ways:

Using an anemometer. High-precision professional device for determining smoke draft.
Ignition of flammable material. The burning material is brought to the chimney grate - with good draft, the flame is directed upward, with poor draft or its absence, it remains motionless.
Visual check. If, when lighting the stove, the flame acquires a dark red tint, this indicates a decrease in draft. Good draft provides a light, almost white flame.
Presence of a strong smell of smoke. If strong odors appear when the firebox is open, this indicates a mechanical blockage of the chimney system.

The full list of reasons why a heating stove starts to smoke is quite long. In each individual situation, it is necessary to take into account: the nature (temporary or permanent) and duration of smoke, indoor temperature, weather conditions, design features and equipment service life.

If the technology for arranging and lighting the stove is followed, the likelihood of smoke in the structure is minimal. But if a problem is still detected, then timely diagnosis and troubleshooting will ensure a long service life of the heating equipment.

There are many stoves in the modern world, but multi-variance is not suitable for a bathhouse; here, since ancient times, the first violin has been played by a wood-burning stove - brick or made of metal. Their internal structure is identical, and the problems that can arise are almost the same. The main thing is a “pillar of smoke” in the wrong direction. In order to correctly determine the cause of unauthorized smoke in a room that occurs when lighting an iron stove (this type of sauna heating device is more popular among owners of private baths), you should first understand what it consists of and how it works.

How to detect reverse draft in a chimney

Now one of the most modern ways to detect its presence (in non-obvious situations) is considered to be an anemometer test. This is an easy-to-use device, today it is not only mechanical, but also digital: just bring it to the inlet and outlet of the pipe, and it will show the current pressure. If its indicators are lower than the already mentioned 10-20 Pa, it’s time to sound the alarm. There is only one thing: this equipment will take readings only in the presence of a wind flow of more than 1 m/s.

What to do if such equipment is not at hand? Use traditional methods:

Light a match, or better yet a candle, bring it to the heating unit and see how the fire behaves. If the tongue pulls into the channel, then everything is in order, but when it remains motionless, there is no air circulation; if it goes to the side, there is a problem.
Visually, that is, see if the room is smoked - even the slightest signs of billowing steam indicate reverse draft. Although this is the most inaccurate way.
If you bring the combustion mirror closer to a working furnace, it fogs up, which means the steam is not being fully released.
Pay attention to the color of the flame when burning wood (peat, gas). If it is golden, everything is fine; when it is white, the extraction is too strong; if it is reddish or red, there is a return effect.
Bring a tape, a paper sheet, a plastic bag to the firebox, holding it by the edge, and see where it moves. If it stays in place, there is no air circulation; if it moves away from you, the system works correctly; if it moves toward you, there is a problem.

Solution

If the stove in your house smokes, first of all you need to check the draft. Throw a lit piece of paper into the firebox and see if the smoke goes up the chimney. If yes, everything is fine. If he tries to escape into the room, this indicates poor traction. Most likely, the chimney needs to be cleaned. There are also more modern methods of checking using special tools - a differential pressure gauge, anemometer, draft meter, but only professionals use them.

If the stove has not been lit for a long time, you can heat the chimney by burning paper and small wood chips

Troubles with reverse draft are eliminated by heating the chimney pipe. This can be done through the cleaning door located as high as possible, by opening the hog in the attic, or by throwing burning paper into the exit hole. Experiments with ignited cellulose are carried out if the first two methods do not work. To avoid this problem, the stove needs to be lit regularly.

Burning paper will also help eliminate gas locks. But you need to burn it in a firebox with the door open, laying one sheet after another. You can also use shavings, sequentially throwing them in handfuls.

To ensure that the stove can operate properly, install deflectors on the top of the pipe. These devices create an obstacle to wind gusts:

The air flow hits the cylinder walls.
It stratifies into many small “winds” and weakens.
Weak currents rise through the pipe and merge with the smoke, pulling it out.

Deflectors increase draft, prevent the creation of turbulence and the return of smoke to the chimney.

Rollover traction

This process can occur after a long period of absence of heating in the stove. Simply put, it hasn’t been drowned for a long time. The chimney and stove cool down to a temperature comparable to the street temperature. As a result, warm air cannot leave the chimney, since there is no heat-conducting flow. To eliminate rollover, there are several proven folk methods. All of them are aimed at increasing the temperature in the chimney area. Here are a few of the most obvious ones:

Every stove contains a door for cleaning the chimney. It is worth trying to heat the air here by setting fire to paper or any readily available fast-burning material;
the previous point can be repeated for a hog in the attic. That is, open it and warm the air in this area;
Well, the most emergency way is to throw burning materials inside the pipe. This method is worth using if others have not helped.

Rules and regulations

If you do not clean the chimney for a long time, it becomes clogged with soot and creates an obstacle to the passage of smoke.

Most often, smoke occurs due to problems with the chimney. It is either clogged or initially arranged incorrectly. The most important point is the height of the chimney. SNiPs indicate the exact dimensions for different structural dimensions of roofs or the location of the pipe structure itself on the roof. For houses with flat roofs, this parameter cannot be less than 60 cm, measured from the highest point of the parapet or superstructures, for example, a terrace canopy.

If there is a garden with tall trees around the house, or neighboring houses are located nearby and higher, it is better to make the pipe larger so that the smoke does not hit obstacles, but goes freely into space.

Wind influence

Air currents generated by the wind penetrate the chimney at high speed, bending around its edge and causing turbulence. If the force of this flow turns out to be greater than the force of the smoke exit, the latter has no choice but to return back to the room. In other words, if the wind is very strong, the likelihood of smoke will be greater.

The effect of wind on draft can be eliminated using a special windproof cap, which should be mounted on the main chimney. It will separate the air flows so that they do not cause turbulence and do not penetrate inside the chimneys.

Smoke when lighting

The stove smokes when lit in the cold season. This problem often occurs with ovens that are not used regularly. For example, the unit is located in a bathhouse or country house. A column of cold air forms a plug in the chimney that blocks the draft. Stove makers advise getting rid of it in the following ways:

bring a burning torch to the smoke collector,
burn a piece of paper directly next to the smoke collector.

These techniques allow the plug to warm up, rise up and come out. The problem of cold plug occurs not only with brick, but also with metal stoves that are installed in bathhouses and saunas (heaters). If the house is 2-story, you should know that the plug often collects in the horizontal part of the chimney, if it is on the 2nd floor. According to masonry technology, the length of this section (box) should not be more than 2 m.

Other causes of stove smoke

Poor-quality mortar, too thick masonry joints, lack of firebox lining or deformation in it lead to cracks in the furnace body. This causes constant smoke; it is not recommended to operate the unit in this condition. Repairs are carried out by sealing the cracks with special adhesive solutions. If this does not help, you will have to disassemble the body and build the stove again.

Smoke coming from a stove into a heated room is an unpleasant and dangerous phenomenon, but it is sometimes difficult for an inexperienced person to determine the reasons for its appearance. Why the stove smokes, possible reasons for its malfunction and tips on how to eliminate them from an experienced stove maker are given below.

Sometimes in calm weather the stove works normally, but in windy weather it either burns or “releases” smoke into the room from the stove door or damper. The cause of this is most likely a tall tree or wall located next to the house. The wind, hitting such a barrier, enters the chimney and prevents the smoke from escaping. To correct the situation, it is necessary to install an umbrella cap on the pipe, which will protect it from the wind. Such a cap is also needed if the stove is difficult to light in hot weather.

If there are no high barriers to the wind near the chimney, then a possible reason why the stove smokes may be the location of the chimney below the highest level of the roof. According to the rules, the pipe must be located at least 25 centimeters above the ridge.

It is very easy to check whether a cap is needed over the chimney if the stove is smoking. Two halves of brick are placed at the corners of the pipe, and a sheet of iron is placed on them. If after 3-5 minutes the stove stops smoking, then a stove hood is needed.

Another possible reason why the stove smokes may be the destruction of the upper seams of the pipe masonry (if it is brick) by rain and exhaust gases, as a result of which the upper bricks fall out of it. The wind gets into the damaged areas of the chimney, and the stove begins to smoke. In such a situation, the pipe must be repaired.

A very possible reason why a Russian stove smokes is the small size of the pipe or views, as well as a poorly closing view door. It is necessary to make overlaps at the top of the pipe, which not only create good draft for the stove, but also improve the appearance of the pipe.

The blower in a Russian stove must be shorter than the firebox, otherwise the cold air entering the blower in large volumes reaches the back of the firebox and, pushing away from it, displaces smoke from the firebox. If you put such a vent in half a brick, then the stove will not smoke.

It happens that the stove smokes in any weather, and when you open the door, the smoke seems to “stretch” after it and enters the room. When this happens, you need to look into the firebox. If there is an oven under the stove stove, then there must be a brick wall between it and the combustion chamber. If it or the cabinet is lower than the top of the door opening, then you need to make a clay border on the wall so that it is higher. The draft in the oven will be excellent even if the height difference between the side and the stove is several centimeters.

Another possible reason why the stove smokes is that the gases exit the firebox below the opening of the fire door. This situation can be corrected by building a brick wall across the firebox, the height of which will exceed the height of the door opening.

If the stove smokes and smoke comes out of the valve or valve, it means that the pipe is clogged with soot or, for example, a brick that has fallen into it. The chimney needs to be cleaned.

Another, quite common, possible reason why a stove smokes is the clogging of the vent with ash, and if the stove is a heating and cooking stove, then the oven burns out.

...and repair the stove

The structure of the furnace is more complicated. To even inspect it from the inside, you need cleaning doors (cleaning). But in a complex stove you may need so many of them that they will spoil the appearance of the room, and a forgotten or loose cleaning can cause smoke and fumes. Therefore, in many house furnaces, cleaning doors are replaced with cleaning bricks sitting dry in the masonry. By the way, according to the same professional ethics, a conscientious stove maker, when handing over the stove to the customer, had to show where the cleaning bricks are. And according to pre-revolutionary legislation, failure by the previous owner of the furnace to indicate to the new owner the location of the cleaning bricks could lead to criminal liability.

If there are no necessary cleanings, then replacement bricks can be easily found by punching. And, what is important, suddenly the cleaning bricks (bricks) showed themselves externally, this is a sure sign that something is wrong with the stove, even if it is still fully operational.

The cleaning brick can “appear” as a depression in the wallpaper (item 1 in the figure), its bulge, or a change in color. A crack appears on the whitewash under the plaster, outlining the brick (item 2), through which air can be sucked into the oven. Further - dirty and hard, but simple, pos. 3-6.

How to find a cleaning brick in a furnace

If the stove is lined, it is more difficult to find cleaning bricks on it. For example, tiled cladding can be tapped with great difficulty. However, even in this case, an ordinary housewife is quite capable of finding hidden cleanings, cleaning and repairing even such a rather complex stove as a Swedish one, see the last video:

Pipe cleaning

Work should begin with cleaning the chimney. All doors in the stove and smoke ducts must be tightly closed and secured. If a large amount of soot falls from a height of 3-4 m, dust may be released into the house. A special brush is used for cleaning; if you don’t have a ready-made one, you can do it yourself. The device will require a strong rope or cable. At one end you should attach a weight weighing 2-3 kg and a pair of old hard washcloths. You can use a fluffy ball of wire, stiff cord, or something similar. The fastening must be strong; parts that come off and get stuck in the pipe can cause a lot of problems.

You need to climb onto the roof with the brush, lower it into the pipe, pull it up and down several times, if possible, rotating and swinging it to the sides. Similar work needs to be done to understand why the fireplace is smoking. If after cleaning the operation stabilizes, the problem is solved. Otherwise, you need to look further.

Minor defects on the inner surface of the walls

Have you eliminated the visible causes of smoke, but the stove still continues to smoke? Another reason for this is cracks on the walls of the chimney and combustion chamber. Cold air penetrates through these cracks, lowering the temperature level, as a result of which the stove smokes. What to do to get rid of small cracks? To do this you need:

Clean the surface, widening the cracks with a chisel.
Prepare a liquid primer by mixing cement with water and thoroughly coat the cracks.
While the treated surface dries, prepare clay grout for plastering, using 2 parts clay and 1 part sand. In order to increase the strength of the mixture, add 0.1 parts of asbestos. Add as much water to the crumbly mixture as needed to achieve a thick consistency.
The cracks are filled using a triangular trowel, the surface is leveled and rubbed with a wooden float.
Leave the plaster and wait until it is about 80% dry.
A finishing layer of grout is applied on top, carrying out independent repairs of the stove, moving in the direction from bottom to top.
After waiting for the surface to dry completely, you should moisten a wooden grater in water and rub in the remaining irregularities, performing smooth circular movements.

Remember that small cracks that form in the tile cladding are rubbed with a solution based on alabaster and chalk.

Experts recommend replacing tiles with significant defects. New and intact products are placed on a solution of clay or fireclay mortar.

Smoking from the stove due to incorrect chimney height

Often the outside of the pipe is built of insufficient height. There is a rule according to which it must exceed the height of the roof ridge by an amount depending on the distance to it:

by 0.5 m at a distance from the ridge of up to 1.5 m;
not lower than the level of the ridge, if the distance from it is 1.5-3 m;
not less than an angle of 10° from the ridge level at a distance of more than 3 m.

If these conditions are not met, the stove will smoke due to insufficient draft and wind currents from the street. This error can only be corrected by extending the chimney. In case of severe wear, a major overhaul is carried out. It involves restoring the masonry and lining it with a metal pipe.

Prevention and testing methods

We told you why there is backdraft in the stove and what to do to eliminate it, and now we want to share the secret of how to prevent its occurrence. There is no secret in this, you just need:

clean the chimney in a timely manner;
regularly heat the system so that it does not stand idle;
eliminate sources of drafts in residential premises;
monitor the condition of devices installed on the pipe.

We have already described the testing methods in the section on identifying the problem, so here we will mention cases in which it is worth carrying out tests with a candle, paper or an anemometer. This should be done when the house has not been heated for a long time, there is (or has recently been) bad weather outside - heavy rain, blizzard, gusty wind, thick fog - and you want, for example, to light a fireplace. This is also true if the rooms, despite the kindling, are cold, or you suspect a malfunction.

And as a conclusion to the review of backdraft in the chimney and what to do when it appears, we offer a video - watch a useful video on this topic:

Channel cleansing

The installation of chimneys in brick walls has two main options:

vertical wells;
horizontal channels.

If the building has a fireplace and stove with a common chimney, it is possible to block the gas path of the fireplace with the flow of flue gases from the stove. For optimal functioning, you can use smoke extractors for fireplaces.

When installing brick chimneys, special cleaning doors must be installed to service them.

What to do if there are no cleanings? You should tap the walls for voids and determine the position of the channels. In places of turns, openings should be made for access to the inside of the channels. When the wells are located vertically, cleaning should be done at the upper and lower bends.

If the channels are located horizontally, cleaning should be done on the sides, on the left and right turns, in the lower part of the channel. Cleaning should begin under the chimney outlet, gradually moving to the side and down.

One of the options for why the stove in the bathhouse smokes may be damp masonry of the stove and smoke duct. In this case, you need to periodically heat the stove with a small amount of wood chips and ventilate the entire system by opening the firebox and vent doors.

The stove always smokes for one reason - the draft is broken. And there are many factors that weaken cravings. Smoke can only occur during kindling or be constant, but in any case the problem must be eliminated immediately, as it poses a danger to humans. To find out why the stove is smoking

and combustion in the furnace has worsened, it is necessary to check all channels of gas movement. In addition, the body is examined for cracks and errors during laying.

The chimney is clogged

It also happens that for some time everything works flawlessly and suddenly one day the stove in the bathhouse starts smoking. What should you do in this case? The reason for this may be a chimney clogged with soot. The problem is solved by simple cleaning. You need to know how to clean a chimney in a bathhouse correctly. If the pipe has no bends, then this will be quite easy to do. Take a rope, attach a brush with a weight to it, and use this device to clean the chimney.

An overcooled chimney pipe can also cause poor draft. This happens in cases where the stove has not been used for a long time. To solve this problem, the chimney should be heated. This is done using a lit rag, which should be soaked in kerosene. The pipe will heat up and there will be no more problems with the operation of the furnace.

Due to the use of low-quality firewood, soot may settle on the inner walls of the chimney. To avoid this, you should first light the stove and then add firewood.

There are stoves in which the size of the blower is equal to the width of the stove. The air entering the furnace from the blower is pushed away from the back wall and goes out. To solve this problem, it is necessary to close part of the blower.

External inspection and repair

To understand why the stove smokes, you need to carefully examine the entire structure from the chimney to the ash pan.

In this case, you need to pay attention to the integrity of the structure, the absence of cracks, loose seams, traces of soot and smoke. Peeled pieces of plaster should be removed, carefully check the condition of the seams between the bricks in a cleaned area

All detected defects must be corrected.

What to do if there is a lot of damage? The best option may be to completely replace the masonry in the damaged area. When used in the upper part of a metal pipe, it can be fixed by arranging temporary fastenings to the roof and attic parts. Then you can begin dismantling the masonry. The brick must be cleaned of old mortar, soot and carbon deposits, and sorted. Then make a new laying.

If there are minor damages, you can remove defective bricks, old mortar, and lay new ones. In this case, it is necessary to ensure that the seams are filled as completely as possible. After repairs, the walls need to be plastered with clay mortar; after drying, it is advisable to whitewash them. In addition to a neat appearance, defects that may occur during further use will be more noticeable on a light surface. After completing the repair work, it is necessary to clean the pipes and chimneys.

Presence of cracks

It's no secret that over the years the stove becomes covered with a network of cracks and cracks. Especially at the junction of clay and metal elements, for example, around a slab. Wells can also crack at the seams.

The cracks could remain in the place where a knockout brick is inserted for cleaning, or the vent and firebox doors have become loose over time.

Also, atmospheric phenomena sometimes destroy the outer part of the pipe on the roof.

It is possible and necessary to deal with cracks, because air is sucked in, its natural flow is disrupted, and at the slightest disturbance in draft for other reasons, smoke finds its way out, even with the door closed!

The cracks are sealed with clay mortar, similar to the one on which the stove is made. Deep cracks are widened using a knife or similar tool to allow the mortar to penetrate deeper between the bricks. Then the gap is moistened with water and sealed well. Small cracks can be whitened.

Furnace structure

Ash pit.

It collects ash and ash - the remains of burnt fuel.
The ash pan is usually closed, which has its own tasks: to remove ash from the chamber and regulate air flows during combustion. Firebox.
Its place is above the ash pit, fuel burns out in it, “charging” the air with heat, after which it leaves through the chimney channels, warming up the walls of the stove and the heater.

In order for fuel waste to fall into the ash pan, the bottom of the firebox occupies

Heater - the location of the container with stones - the concentration of all the heat and steam from the sauna stove. The entire “weather in the bathhouse” depends on the correct shape the bathhouse owner chooses for the heater, and what size it will be.

The heater can be open or closed; this determines what mode of operation of the firebox will be - constant or periodic.

The last structural elements are the chimney pipe and chimney shaft

. Through them, warm air, heated in the stove, goes outside, beyond the walls of the bathhouse.

Temporary backdraft

This is not a permanent problem, but a one-time or periodic one, manifesting itself within a short period of time, literally a few days. In practice, it most often occurs after prolonged bad weather (with dense fog, constant downpours, snowfall) or prolonged downtime of the heating system.

It can be explained simply by the formation of a plug of cold air in the pipe. It can also be easily eliminated - by burning several sheets of paper. This way you will warm up the channel and break through the barrier. It’s even better to install a stabilizer - it will help normalize the pressure in the sleeve.

Main causes of smoke

The stove smokes due to design defects or blockages in the chimney

Owners of private houses are often faced with the fact that on windy days the stove “spits” smoke. This usually occurs due to insufficient head height. But it doesn't always need to be rebuilt. Enough to fix it, increase the visor.

There are other reasons for smoke:

The craving weakens or disappears. It can occur due to the chimney being clogged with soot or snow, insufficient air flow, and sometimes due to structural defects in the smoke duct.
The stove's power is increased. Smoke occurs in improved designs, for example, a bell-type stove, if they try to “heat it up” more than it is capable of.
There is not enough air flow. If the doors and windows are tightly locked, the stove begins to “suffocate.”
The draft overturns. Most often, this occurs if there has been no kindling for several days. Due to idle time, the air flow does not go outside, but is drawn into the room along with the smoke.

The operating time of the furnace depends on the quality of its construction and materials. But sooner or later any structure wears out. When a stove ages, a thick layer of soot accumulates inside, reducing the clearance of the chimney, and cracks form in the brick sides, breaking the seal. These are also possible causes of smoke. This requires cleaning and restoration of the device.

The wind cap also protects the pipe from destruction

If a completely new stove has problems with smoke, it is usually due to imperfect design. You need to call a stove-maker to determine whether something can be changed with little effort. Most likely, it will be easier and cheaper to modify the structure than to destroy and rebuild the stove.

These reasons apply to almost all modifications, including the Russian stove. But with simple large heaters it is hardly possible to boost the power.

The stove in the bathhouse, sauna or garage may have special reasons for smoke. If the chimney becomes clogged with soot and dirt, she will also begin to “strain” and “snort.” The same goes for cracks in the wall that urgently need to be covered up. But there are special problems that arise when heating small buildings with stoves. There may be an obstacle located near the bathhouse. The smoke hits it and comes back. To cope with the disaster, you need to equip the sauna pipe with a windproof cap. Since the sauna is not used every day, due to temperature changes, the top of the pipe begins to collapse. It needs to be repositioned and, if necessary, increased a little.

If the stove in a bathhouse or utility room is built incorrectly, it needs to be redone.

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

Now that the causes of backdraft in a chimney or boiler and their elimination are clear, let's see what happens if the problem is ignored.

If nothing is done, combustion products will accumulate in the pipe, which will then return to the living quarters. They are dangerous because they contain carbon monoxide, which can cause poisoning or even death. Anyone who does not want to correct problems risks the health of themselves and their loved ones.

It should also be noted that the efficiency of the equipment decreases, and therefore the cost of heating the house increases. This, of course, is not a threat to life, but it is a moment that punches a hole in the budget, that is, it cannot be neglected either.

Why does it smoke?

Smoke in a bathhouse is not only unpleasant. It is also very dangerous. Any schoolchild knows: during the combustion process, carbon monoxide is formed - a strong poisonous substance. So you need to carefully ensure that only steam and heat, and not smoke, remain in the room where you like to have a good time.

So, for what reason does the stove smoke in the bathhouse and what to do about it?

The simplest reason (this can occur if you did not design and install the bathhouse and stove equipment) is that the stove “does not work” due to the internal diameter of the smoke exhaust pipe being too small. If this figure is less than 120 mm. - change the pipe.
This reason is more difficult to eliminate (and most likely, you will not be able to master the process on your own), but you will still have to do something: if a metal sauna stove starts smoking during the first fire, there is a high probability that you installed the unit incorrectly or made errors in the design
However, do not rush to panic! Perhaps the problem is not in the design of the furnace, but in the pipe, and then it will be relatively simple to correct the situation.

Technical nuances

Overheating is equally dangerous for both metal and refractory brickwork, especially in the seams. Metal parts are prone to warping, bending, directional twisting, and burning. This is especially true for lightweight steel stove models. A few subtle but serious defects are already enough to cause a headache like why an iron stove smokes in a bathhouse. And if burnouts can, in most cases, be melted by inverter welding with repair heat-resistant electrodes or eliminated by applying patches, which is more correct, then warping and other linear deformations must be straightened, often painstakingly embroidering problem areas using an angle grinder cutting disc, and then restoring and strengthening the damaged geometry of various kinds of inserts, scarves, segments and other additional elements.

A few words should be said about why there is poor draft in the furnace, which is associated with the production culture determined by the construction of the furnace and the technical arrangement of smoke channels. Like any heating device whose operation involves burning fuel, the stove emits combustion products, both solid and gaseous. The dynamics of gases is associated, first of all, with the presence of certain obstacles in their path. It is not without reason that when constructing a chimney, responsible executors use such a technological technique as “scraping”, the essence of which is to eliminate various types of irregularities and obstacles in ducts, chimneys, distributors, and outlets. In metal single-wall pipes, a mandatory element is a condensate receiver glass, the purpose of which is to collect and remove condensate from the zone of movement of flue gases, preventing them from being moistened and cooled. The presence of these elements, as well as a sufficient number of service doors, will help to avoid an unpleasant situation when the stove in the bathhouse smokes, what to do, where to run.

Do-it-yourself stove and chimney cleaning

You can clean the chimney yourself or call a specialist with professional tools

If the stove is used for seasonal heating and cooking, the chimney should be cleaned once a quarter. This should be done more often if resinous or damp firewood is used. This causes excessive deposits and narrowing of the lumen. Mechanical cleaning can be done independently using traditional techniques that have not changed over the past centuries. Work is carried out wearing protective glasses and gloves. For activities at heights, you need non-slip shoes and insurance.

From the roof side

You will need a cable on which hard brushes are attached to clean the chimney from soot, and a heavy round weight with an eye. A brush can be made from an old plastic bottle.

Cleaning is carried out in five stages:

To prevent soot from entering, cover the firebox and hatches with a wet rag.
Remove the head and inspect the canal.
Clean with a broom to remove cobwebs and debris.
Use a weight to break through the blockage several times.
Clean the chimney walls with brushes.

Finally, you will need to clean up the soot from the roof and inside the firebox.

Wear

Over time, the materials from which the stove is constructed deteriorate. Constant temperature changes, soot accumulation, exposure to condensation and other physical processes that occur when smoke passes through all areas of the stove can affect the structure of the brick or the material from which the stove is made.

Violation of the integrity of the structure can cause the appearance of small microcracks and noticeable holes, which significantly impair overall traction. The combination of soot and condensation can cause carbon deposits to form on the inside of the chimney, thereby narrowing it. Which, in turn, also affects cravings. The chimney pipe, which can also be made of materials that deteriorate over time, is also subject to destruction.

To eliminate wear and tear, the furnace will need to be cleaned and reconstructed, the complexity of which depends on the complexity of the damage. In particular, it is necessary to eliminate the accumulation of soot, remove exfoliated masonry elements from the chimney, and get rid of depressurization by sealing cracks and holes with a solution.

If the damage is very serious and you cannot fix it yourself, there is only one option left - contact a specialist.

Video.

There is no draft, the stove smokes, and, as a result, condensation forms and the casing begins to collapse. Both the stove maker who made a mistake when laying the stove, and the owner of the house due to inept handling of it, may be to blame for these troubles. Indeed, such a situation for a rural resident living in a house with stove heating in the winter turns into serious problems. In order for the stove to work properly, you need to know what causes the “whims” of the stoves.

The oven with hob heats up slightly

Check whether the valves are opened correctly when firing the stove in summer and winter.

The stove burns sluggishly and smokes

Check that the oven cleaning holes are properly sealed. The lack of good draft is observed when burning with damp wood, when the pipe is poorly heated, when the chimney is narrowed, or when the chimney has right angles.

The chimney needs to be expanded.

If the narrowing is caused by soot deposits, clean the chimney.

Cut right angles in the path of hot gases.

The stove smokes during the summer fire

Violation of draft on a hot day causes cold, compared to outside, air filling the pipe.

It is necessary to preheat the pipe with a bunch of burning paper or wood chips, placing them into the pipe through the view doors.

If there is a summer operation, you must first heat the stove in summer mode.

The stove begins to smoke some time after the fire starts

. Often a similar problem occurs in homes due to a lack of outside air flow. When fuel burns, air is consumed, its pressure in the room decreases, and draft is disrupted.

To equalize the pressure in the room with outside atmospheric pressure, open the window.

Formation of condensation in the pipe

When any fuel is burned, the water contained in it turns into steam and rises along the chimney along with the flue gases. When the flue gases are cooled to a temperature below 100 degrees, the steam condenses, the resulting liquid, mixing with soot and resins, flows down the pipe. During the cold season, moisture freezes and gradually destroys the brickwork. With proper combustion in a properly built stove, the temperature of the flue gases at the view should be about 240 degrees.

What are the reasons for the low temperature of flue gases in the chimney and how to eliminate them?

Use of fuel with high ash content

(peat). A large amount of ash generated during fuel combustion clogs the grate, which leads to a decrease in air flow. The fuel burns poorly and the temperature drops.

For efficient combustion of fuel, you need to reduce its layer and periodically remove ash from the ash pit.

Obstructed passage of flue gases

. A similar problem is typical for stoves with a long narrowed hog and with turns at right angles.

Errors made when laying the stove are eliminated.

A short pipe impairs traction

. The rate of fuel combustion and, accordingly, the temperature of the flue gases decrease.

The chimney should be extended.

The internal diameter of the chimney has been increased

. The slow rise of gases through such a pipe leads to the entry of cold outside air into it and cooling of the flue gases.

The chimney outlet should be narrowed.

The grate is not completely covered with fuel

. The bulk of the air passes by the fuel, which leads to cooling of the flue gases.

Distribute the wood evenly on the grate and stack the logs tightly together.

A decrease in the temperature of the flue gases can be caused by the influx of air through loosely closed combustion doors and stove burners, through cracks in the stove, and dampers.

Proper care and timely cleaning of chimneys from soot is a guarantee of stable operation of the stove in the coming winter season. In addition to the mechanical method of removing soot, chemical means are currently used, for example, “Jolly Chimney Sweep”.

After using this product, after some time, the soot separates from the walls of the chimney and settles at the bottom of the well. All that remains is to remove the soot through the cleaning doors.

The case is a pipe

. This expression, taken from V. Dahl’s dictionary, perfectly describes the situation when the stove, which has worked faithfully for you for several years, suddenly begins to “shoot” smoke, smoke, and does not melt well... What should you do in such situations? Remember the last time you looked into a chimney? And did you look at all? Meanwhile, all more or less reputable publications on the stove business recommend periodically inspecting the masonry and cleaning the pipes and chimneys at least once a year.

It is best to do this “dirty” work in early autumn. It’s not cold yet, and you can carefully, slowly, inspect all parts of the pipe in the attic and above the roof. If you find slot holes in the masonry or signs of destruction of the fluff, hog, riser, otter and head, immediately eliminate all defects and flaws and begin cleaning the inner surface of the pipe. It’s ideal if you can find tools for cleaning soot from a friend of yours. If there are no such items, make something like a brush yourself. It can be successfully replaced with a nylon washcloth made of thick threads, placed in a string bag with a cobblestone. But the best choice for this purpose is the used brushes that are equipped with garbage collection machines. If you have a coil of steel wire, cut it into pieces so that they completely cover the cross-section of the chimney. Next, drill holes in a piece of duralumin tube around the circumference and insert the cut wire into them. Fill the cavity of the gravity tube with molten lead, inserting a wire loop for garter to the “ruff” of the rope.

Having completed cleaning the central chimney outside the house, quickly clear the surface area of ash and soot from the layer of ash and soot. This can be done without even lifting the cast iron stove - through the burner.

There is more hassle with cleaning the smoke ducts. It's good if they have cleanout doors

, and when instead of them halves of bricks with mortar are inserted into the masonry? You need to know these walled up holes and carefully use a chisel or small spatula to pick out the seams and remove the insert to get to the clogged channels.

In summary, all other reasons that the stove smokes are as follows.

1. The weather is windy and the pipe is not equipped with a windproof cap. Wait for the wind to stop or climb onto the roof to install the cap.

2. The pipe is below the roof ridge. It is necessary to extend the pipe as soon as possible.

3. Rains, frosts and winds partially destroyed the outer masonry. Wind blows into holes and cracks, forming air plugs that interfere with normal traction.

Without delay, begin restoration work.

Remember that any crack in ovens can cause a fire. This is especially true for old furnace structures with flue ducts lying in the attics.

4. The cleaning door turned out to be defective and does not cover the cleaning hole tightly. In such cases, it is better to temporarily block it (the window) with a piece of brick coated with clay mortar.

5. If you heat your stove with firewood, remnants of vegetation from the site, brushwood, straw, then the length of the blower should be reduced by placing half a brick flat or on a spoon at its end.

6. After kindling, when you open the door, you notice smoke as if stuck to it. Look for a defect in the combustion chamber. If a welded oven is installed next to it, place bricks along it on spoons flush with the top of the door frame. If the gas outlet channel is made below the combustion door or flush with it, insert a brick jumper at the back wall of the firebox at the level of the top of the combustion door (Fig. 2). The smoke will then begin to “bounce”, contributing to the draft.

7. Smoke seeps in whitish streams through the summer valve that is not completely closed. It is necessary to determine whether a foreign object has fallen into the chimney and whether the chimneys are clogged with soot.

8. If the underground is damp, the chimneys may become saturated with moisture over the summer. They should be dried thoroughly by opening the bottommost cleaning and making a small fire of dry wood chips in it. You can use dry alcohol tablets for the same purposes. At the same time, start heating the stove itself. When the traction is restored, wall up the cleaning again.

9. The cause of smoking can be a burnt-out oven wall, a ash chamber clogged with ash, the small size of the gas collector, or an incorrectly selected cross-section of the main chimney.

10. If you have a fireplace attached to a stove with gases escaping into one chimney, you must start heating from the fireplace.

11. If chimneys from two stoves are connected to the same pipe at the same level, a cut should be made between them (the chimneys), or one of the stoves should be connected to the riser through an inclined chimney at a different level - higher or lower.

12. Resinous soot is burned directly in chimneys using dry splinters or special stove matches that have appeared on the Russian market.

Category: Stoves