Wood Stove Closing Vent

How To Use The Vents To Control A Wood Burning Stove

In Indoor Fireplaces, Wood Burning Stoves by James O'KellyLeave a Comment

Wood burning stoves help to increase the heat output and improve the efficiency of burning wood in your home compared to using open fireplaces.

Wood stoves provide an environment in which both the amount of fuel and the air supplied to the fire can be controlled to help you have hotter and longer fires, while also helping to reduce the amount of wood used.

The guide explains how to use the air vents on a wood burning stove to control a fire.

To control a wood burning stove:

  • Before lighting a fire, ensure that all of the controllable air vents on the stove are open.
  • Leave the vents fully open when lighting a fire and while the fire gets going.
  • Slowly start to close down the vents once the fire has caught hold of the kindling. Leave the vents fully open for a longer period of time if closing down the vents causes the fire to smolder or go out.
  • Adjust the air vents throughout the fire to keep it going. Close down the vents to maximize efficiency, without causing the fire to smolder. Open the vents more to increase heat output but reduce efficiency.

This guide is for controlling the air vents on a wood burning stove.

For a guide to controlling the vents on a multi fuel stove, click here.

To find out how to tell whether a stove is multi fuel click here, and see the complete list of differences between a wood burning stove and a multi fuel stove here.

I’ve explained in more detail below how we use the air vent on our wood burning stove to control the heat output from the fire.

How To Use Vents On A Wood Burning Stove

When the door to the stove is closed, all of the air supplying the fire comes through the vents. As these vents can be controlled, how quickly the fire burns through the wood can be adjusted for either maximum efficiency or maximum heat output.

Depending on your model of wood burning stove, it may have one or more controllable air vents.

Our wood burning stove has one controllable air vent that is located underneath the stove, while there are also air vents located on the back of the stove that can’t be controlled.

The air vent on our wood stove supplies both primary and secondary air to the fire (more about types of air in stoves here), and is controlled by a handle that sticks out the front of the stove.

Wood Stove Air Vent Handle
The main air vent control on our wood burning stove
The handle controls an air vent located underneath the stove

This vent can be opened by pulling the handle away from the stove, while pushing the handle towards the stove closes the vent.

The air vent fully closed, preventing any air from getting into the stove
Opening up the air vent on our wood stove

Opening this vent increases the air supply to the fire and therefore increases how fast the fire burns through the wood and the total heat output. The fire burns through the wood more quickly as a result and so you’ll be adding logs to the fire more often.

Closing down this main vent reduces the amount of oxygen getting to the fire, therefore decreasing how fast the fire burns through the wood and reducing the total heat output. The wood burns more slowly as a result.

This vent provides air to both the fire (primary air) and air to the air wash system (secondary air). The air wash system helps to keep the glass door clear on our wood burning stove, and you can find out more about air wash on stoves in another one of our articles here.

On many other models of wood burning stove, the secondary vent can be found on the front of the stove near the top.

As wood burns best with a source of air from above, this vent may therefore be used to control the fire, as well any air wash or secondary combustion systems in your stove.

There is also a row of small air vents located at the back of the firebox. These vents supply tertiary air to the fire to aid in secondary combustion of gases to help produce more heat.

Wood Stove Tertiary Air Vents
The row of tertiary air vents at the back of our wood stove (these can’t be manually controlled)

These vents can’t be closed, and if your stove has these types of vents it’s important to never build the fire higher than these vents.

Check the manufacturer’s instructions for your particular model of wood burning stove to see which vent(s) are supplying air to the different components of your stove, which will help you understand how to best control a fire in you stove.

How To Control A Wood Burning Stove

The air vent(s) on a wood burning stove can be used throughout the duration of a fire to help control how quickly the fire gets going, how quickly it burns through the wood, and how much heat is produced.

Starting A Fire

Before lighting a fire in a wood stove, ensure that all controllable air vents are fully open.

The aim at the start of any fire is to get it going quickly and get the stove up to operating temperature. A fire requires a lot of oxygen at the start, and fully open air vents helps to get a fire going.

Wood Stove Vent
All air vents on your wood burning stove should be fully open before lighting the fire

The air vents should remain fully open while the fire takes hold of the kindling and starts to rapidly burn through it.

Keep the vent(s) open while the fire catches alight of the kindling

At this point we like to add a further log to the fire, and also start to slowly close down the air vent as the fire progresses without causing the fire to smolder or go out.

Wood Stove Closing Vent
Start to slowly close down the primary air vent once the fire has really got going

Every model of wood stove is different, and so if you’re having trouble keeping a fire going it’s fine to leave the vents fully open until the fire becomes more established. Adding larger sized pieces of wood too early into a fire can smother the fire if it isn’t yet hot enough.

I’ve explained in more detail how to build and light a fire in a wood burning stove here.

Keeping A Fire Going In A Wood Burning Stove

Once a fire has successfully taken hold of the kindling and a bed of hot coals has started to be formed, the air vents on a wood burning stove can be used to ensure that the fire remains going strongly, while also making sure the most amount of heat is being produced from every piece of wood.

Larger sized logs are harder to catch alight than smaller pieces of wood, and so it’s best to build up the fire progressively over time. This can be done in conjunction with slowly closing down the air vents until the wood stove is operating at its most efficient level.

To keep a fire going in a wood burning stove, the air vents shouldn’t be fully open, but closed down enough so that enough air is being supplied to the fire to keep it going, without causing it to smolder.

If the vents on a wood stove are open too far, then too much oxygen will be getting to the fire and it will be rapidly burning through the wood. Although more heat will be produced, the rate at which the fire is burning through the wood makes it very inefficient.

If the fire is burning too quickly, simply close down the main air vent in small stages until the fire is burning slowly and efficiently.

Wood Stove Closing Vent
Close down the primary air vent if the fire is burning through the wood too quickly, without causing the fire to smolder or go out

On the other hand if the vents are too far closed, the fire will be starved of oxygen and start to smolder, and can end up producing a lot more smoke as a result. A lack of air can also cause the fire to go out completely.

In the fire in your wood burning stove is struggling to stay alight, open up the main vent as much as possible to get the flames going again. At this point you may need to start closing the vent back down in small steps to bring the fire back to being its most efficient.

Smoldering Fire
Open the primary air vent back up if the fire starts to smolder and smoke

Understanding how best to use the vents on your wood burning stove to control a fire is a learning process. Keep using your stove and you’ll find out how far into a fire you’ll be able to starting closing down the air vents, and by how far without causing the fire to smolder.

Further Reading

How To Build And Light A Fire In Wood Burning Stove

How To Warm The Flue Of A Wood Burning Stove

Leave a Comment