Smoke billowing out of a stove into your room is a frustrating issue. But the good news is that it’s a common problem and is not always as alarming as it seems. Several factors could contribute to smoke leaking from your wood burner, and it is a simple fix in many cases.
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The baffle position
The baffle is a heavy-duty component located at the top of the firebox inside your wood-burning stove. It’s typically made from metal so that it can handle the heat. The baffle plate traps the heated air and waste gases inside the firebox for longer, producing as much heat as possible from the burning wood.
Usually, the baffle plate will be angled upwards towards the front of the stove.
The main thing to do if you have noticed smoke leaking from your wood burner is to check that the baffle is in the proper position. The purpose of the baffle plate is to reflect the heat to the firebox, allowing the fire to burn as efficiently as possible. The culprit behind a stove smoking is more likely to be the chimney if the baffle is in the right place.
Some newer wood-burning stoves have a tighter, more restrictive baffle design to boost efficiency. However, they only sometimes perform well when attached to a chimney that could be better. If you are struggling to see how the smoke travels up the chimney when you look inside the stove, then this might be the issue.
Problems with the chimney
The chimney is often the most common reason behind smoke puffing out of your wood burner. Our previous article, Why Is My Wood Burner Smoking? addresses common chimney issues such as blockages or a cold chimney in more detail.
The chimney must draw air upwards for your stove to work well. Drawing creates suction and pulls the smoke up around the baffle before it escapes through the chimney. If the chimney is not correctly drawing the air, it will fail to create the required amount of suction, ultimately forcing the smoke back down the chimney and out into the room instead.
Several potential problems can lead to drawing issues in the chimney. Some homes may have one or more of these chimney problems, leading to smoke billowing out of the wood burner.
If the baffle is in the correct position and your stove has been performing well up until now, a blocked chimney might be the culprit if you’ve noticed smoke coming from the log burner into the room. A blocked chimney can be dangerous and cause the space to become filled with hazardous carbon monoxide. So, you should fix it as soon as possible.
Regular chimney sweeping is essential to prevent the chimney from becoming blocked over time. The most common cause of a blocked chimney is the slumbering down of wet wood, which produces large amounts of tar amassing on the chimney liner over time. Eventually, the blockage becomes large enough that the smoke can no longer pass through.
You should also set a CO alarm in your home to alert you to dangerous carbon monoxide levels.
If the chimney is short, this is another common reason smoke is pulled back through your log burner. There is insufficient suction to successfully draw the smoke upwards and through the chimney.
While a tall chimney will create decent suction and a good pull for the smoke to escape through the pipe, a chimney that is too tall can become a problem. As the smoke travels upwards through the tall chimney, it will begin to cool, causing it to sink. In a regular brick chimney, you can use vermiculite for insulation. A ThermaFlue Insulation Sleeve can insulate the flue and ensure warmth if the chimney has been fitted with a flexible flue liner.
Negative pressure in the chimney
Negative pressure occurs when cold air travels down the chimney. This could be the culprit if you notice that smoke is more likely to billow from your log burner on a cold or foggy day.
The cold air forces the smoke back down the flue and out through the stove, as cold air sinks while hot air rises. This problem is usually seen more often with a twin-walled chimney system since these tend to be more exposed to the elements.
Can the weather cause a stove to smoke?
In some cases, weather conditions can be the leading cause of smoke coming out of your log burner. For example, suppose your home is exposed in a hilly area or within a valley. In that case, the high winds can make it difficult for the flue gases to effectively exit the system, pushing smoke back down through the chimney and out of your stove.
If this problem persists for you, then it may be necessary to have a specialist chimney cowl fitted.
How to prevent smoke coming out of your wood burner or multi-fuel stove
You can do a few simple things to reduce the risk of your stove smoking.
1. Keep it clean and well-maintained.
Blockages are a common cause of smoke coming from a log burner, so keeping your fireplace and chimney clean is essential. Not only does this prevent the frustrating issue of smoke entering the room rather than going up the chimney, it will also keep your wood burner safe and reduce the risk of fires or CO leaks.
2. Only burn seasoned, untreated wood.
Burning wet or chemically treated wood in your fireplace releases toxic gases into the environment. It can cause more sludge in the fireplace and chimney, increasing the chances of a blockage. Only burn well-seasoned wood with a moisture level of no more than 20%.
3. Use some newspaper to test the chimney pull.
You can light a piece of newspaper and hold it high in your wood-burning stove to test the draught of your chimney. You can expect the paper to burn well if there is a good draught. On the other hand, if your chimney has a poor pull or blockage, the lit paper may go out quickly or struggle to burn consistently.
4. If you have a grate, ensure it’s in the proper position.
If you have a multi-fuel burner with a grate, then make sure that this is placed correctly in the firebox, with a few inches on each side. The grate positioned too far forward can draw smoke from the stove into the room.
5. Open the air intake to create a pull before you light the fire.
Before opening your stove, get a good upward draught going. You can do this by opening the air intake a few minutes before you open the stove door to help avoid smoke puffing into the room once you light the fire.
6. Check that the chimney height isn’t the problem.
If you are still having problems with smoke coming from your log burner into your room after doing all the above, then it may be necessary to have your chimney height checked by a professional. You may need to have it adjusted with insulation or a specialist cowl system if the chimney is too tall or too short.
Smoke from your log burner or multi-fuel stove can be frightening and frustrating. Thankfully, you can trace it back to one of a few common causes. There are a few things that you can do when operating and maintaining your stove to prevent it.
We hope this guide has helped you ensure a better, safer experience using your log burner or multi-fuel stove.
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