Causes of backdraft in a furnace

When using wood heating, fireplaces or stove complexes, people sometimes encounter the fact that the smoke does not go up the chimney, but rushes into the room.

This phenomenon is called backdraft. The reasons for its occurrence can be very different.

Why does backdraft occur?

Any appearance of the smell of smoke or soot in the room where there is a wood-burning stove or fireplace should alert the owners.

IMPORTANT! The appearance of smoke in a room is always life-threatening and requires urgent elimination.

Not only does the unpleasant smell cause discomfort, but the soot stains ceilings and things. Carbon monoxide is also hazardous to health.

If you see or smell that the stove has started to smoke, then you need to look for the reasons for this and eliminate them. Let's figure out why backdraft occurs in the chimney.

Effect of chimney design

The installation of chimneys in a fireplace, Russian stove or Swedish stove is made according to different schemes. If the design was carried out with violations, the owners of the house will have to face this unpleasant phenomenon.

• Backdraft can also occur when pipes are cloggeds soot;
• If the pipe is too low relative to the roof ridge smoke may enter the room.
• The lack of a chimney cap becomes another reason.

If the stove is clogged, a persistent smell of smoke will appear when lighting, when opening the door, or when closing the vent.

Such symptoms indicate a chimney clogged with soot or errors in its design (if smoke occurs in a new stove).

Effect of ventilation

Good draft is impossible without proper air circulation in the firebox. To regulate ventilation, stoves have special dampers on the pipe and stove ash doors. If, when igniting the stove, a reverse draft suddenly occurs or there is no draft at all, then the smoke goes into the room. In such cases, the first thing you need to do is check whether the damper and the vent are open.

IMPORTANT! To enhance the air flow, it is also necessary to correctly place the pipe on the roof. If its upper edge is located below the ridge of the roof of the house, then the occurrence of reverse draft is inevitable.

Natural factors

In areas where strong winds and drifting snow often occur during the cold season, reverse thrust can occur during sudden gusts.

To eliminate this problem, special dividers and caps on the chimney pipe are needed. They will help weaken the wind gusts, and it will not blow smoke back into the room.

It often happens that you have to heat a house due to night dampness or an “uninhabited spirit.” If this is done during the day, then the temperature outside is higher than in the house. In this case, the occurrence of reverse thrust becomes commonplace. As the chimney and firebox heat up, normal air circulation is restored.

Chimney condition and operating features

As stated above, the accumulation of soot in chimneys leads to a decrease in draft and the appearance of smoke in the house.

Experienced stove makers advise to always light the stove with the damper and vent fully open.As the chimney warms up, the soot burns out and turns to ash. Then he goes out into the street along with the smoke.

The importance of eliminating backdraft

Why is the appearance of backdraft in a furnace so dangerous?

First of all, because carbon monoxide can cause death. Its atoms replace oxygen atoms in the blood and cause asphyxia or severe poisoning of the entire body.

You shouldn't risk the lives of your loved ones. It is better to immediately turn to professionals if you have the slightest problem with the stove. They will clean the chimney and correct defects in the design. They will also advise you on how to properly handle a fireplace or stove.

It is easier to prevent trouble than to suffer later.