How to Control Wood Burning Stove Vents Properly

Written by: Paul Cathro

Updated on: January 11, 2023

wood stove side and front view

You need heat, fuel, and oxygen to make and sustain fire. While open fireplaces get oxygen naturally and burn fast, stoves have vents that feed a firebox, creating an enclosed environment that extends the burn time. 

You can find stove vents above and below the glass, with the bottom vent being the primary vent and the top vent secondary. 

Controlling the vents lets you adjust the oxygen flow to the chamber and, in turn, how quickly the fuel burns and the stove temperature

But precisely how do you control wood-burning stove vents? This guide explores everything you need to know to keep your fire roaring. 

What Are Wood Stove Air Vents?

When your stove door is shut, all the air entering it comes from the vents. 

Wood stove air vents are gaps in the stove casing that allow air to enter – but not escape – the firebox. Stoves need air to burn fuel and circulate gases, so they move up the flue and out of the chimney. 

Every wood-burning stove has a top and bottom air vent that you control, and some have a tertiary (rear) air vent that is fixed. The idea is to control air flowing into the firebox to increase or reduce the fire ferocity and temperature. 

You can starve your fire of oxygen by keeping the vents closed and equally overdo it by keeping the vents wide open all the time. 

Under-fueling a stove with air produces smoldering fire at a low temperature while overdoing it burns through firewood too rapidly. Thus, controlling air vents is crucial to owning a small stove and getting the most out of it. 

The good news is that you don’t have to man your stove all the time – but you do need to watch for signs that it needs oxygen or less of it.  

Unlike central heating systems and generators, which magically work once you press a button, or the timer comes on, wood-burning stoves require care and attention for optimal running, but this is all part of their charm!

How to Use Wood-Burning Stove Vents Effectively

Firstly, you should familiarize yourself with how the vents on your stove work. 

Your wood-burning stove will have a handle sticking out at the front or side to control the bottom and top vent - we recommend playing with the handles to see how much tilt opens, partially closes, and closes them for efficient control

Additionally, the bottom and top vents serve different purposes. The bottom vent fuels the fire from the bottom, increasing how quickly and hot the fire burns, while the top vent has a more significant role in moving air around the firebox. 

Every wood-burning stove has unique characteristics, but generally, you open both vents when lighting a fire and close them gradually once the fire is established. 

Here’s how to use wood-burning stove vents:

  • Open both vents when lighting the fire.
  • Let the fire rage for ten minutes and establish.
  • Once you see embers, partially close the top vent.
  • After another ten minutes, close the top vent (the fire at this stage should be a moderate flame).
  • After ten more minutes, partially close the bottom vent and keep an eye on the fire – it should have a low flame with red embers.
  • The fire should keep whirring with the bottom vent partially open, but if it dies down considerably, you can open the top vent partially.
  • You can also open the firebox window to increase airflow if the fire needs lots of help after an extended period of smoldering.

This method aims to throttle down the top vent while keeping the bottom vent in action to keep air flowing without turbulence. 

It is crucial to remember that the top vent circulates air within the firebox more so than the bottom vent, so if you have partially lit firewood or the fire is hotter on one side than the other, the top vent offers ultimate control. 

The bottom vent keeps the fire raging and the embers hot – wood burns best with a bed of ash, and the bottom vent keeps air flowing through it. 

Displacing the ash is usually required once the first logs have burned down to ash with only a few embers remaining. This will ensure that any new fuel you throw on the fire gets lots of air to feed combustion. 

Lastly, air vents won’t save a fire without any embers – once the embers are gone, you must clear the stove bottom and start a new fire. 

Related: The Cubic Grizzly is one of our favorite small wood stoves. Find out why in our review.

When to Have Wood Burner Vents Open or Closed

You should have both vents open when starting the fire and for ten minutes afterward, during which the flames will peak and die down as the firewood combusts. After ten minutes, you can partially close the top vent. 

The bottom vent should stay fully open until all the fuel is completely burnt – without the bottom vent open, the fire won’t last an hour. 

While some guides recommend closing the bottom vent partially, this increases the risk of smoldering fire because insufficient air will get through the ash bed. This will stunt burning and reduce the temperature inside the firebox. 

If your stove fire dies and needs help, the bottom air vent might not be fully open, or you can open the top air vent to circulate air. You should also add more fuel once the logs have burnt down into red embers. 

You can also save a smoldering fire by opening the firebox window and displacing the ash bed, increasing air flowing to the embers. Keep the bottom and top vents open to maximize airflow and introduce kindling as a combustion aid. 

If you want to kill the fire within half an hour to an hour, you can close both vents, and it will die down without any fuss. 

How to Control a Wood-Burning Stove Fire

Oxygen is but one element of controlling a wood-burning stove. 

People’s biggest mistake with wood-burning stoves is assuming the air vents will do all the work of making a rip-roaring fire, but there is more to it than that

The air vents supply oxygen to slow or speed up combustion - but they are only one element of a fire. To make a good fire, you first need to build a fire from the top down, so everything combusts evenly, and then add more fuel when you have a bed of hot embers. 

You need heat, fuel, and oxygen – ultimate stove control is achieved by mastering each element since they are intrinsically linked. 

Here’s how to control a wood-burning stove correctly:

  • Open the stove window and the top and bottom vents.
  • Optional - place rolled-up newspaper inside the stove and light it. The heat from the newspaper will remove cold air from the flue and start a draft.
  • Build a fire using the top-down method, where you place large logs at the bottom and kindling at the top.
  • Light the fire at the top – the kindling will burn and fall with gravity, igniting the logs and kick-starting a roaring fire.
  • Close the firebox window after five minutes and leave the vents open.
  • Wait ten minutes.
  • Once the logs are on fire, and there’s a bed of ash and embers at the bottom of the stove, partially close the top air vent.
  • After ten more minutes, fully close the top air vent.
  • Leave the bottom air vent fully open to keep the firebox temperature high.
  • If the fire struggles or you have unburnt logs/kindling, open the top air vent to circulate heat around the firebox to improve combustion.

Problem Scenarios 

You might also experience a few problem scenarios. Here's how to handle issues that might arise.

  • Your stove will not get going – the wood might be moist, or the firelighter might be burning too quickly to heat up the fuel. Firstly, check if the wood is dry, and use a bunched-up newspaper as a firelighter. 
  • Your stove is burning too hot and fast – partially close the top and bottom vents until the fire is under control.
  • Your stove is not hot enough – increase airflow by opening the top and bottom vents or open the firebox window and add more fuel.
  • You have inconsistent combustion – open the top vent fully to circulate air.
  • The ash bed is too thick and is impacting the fire – open the firebox window and displace the ash with a poker. Open the bottom vent to increase airflow and restart the fire (if out) with kindling and a firelighter.

Overall, controlling a wood-burning stove isn’t rocket science. Providing that you build the fire correctly and keep air flowing to it via the vents, you can maintain a healthy fire, extend the burn time, and reduce fuel consumption. 

Almost all wood-burning stoves have the same start-up sequence, but since all installations have quirks – be it stainless steel instead of a vermiculite baffle or a larger flue due to the design of the building – it can take a little time to get the hang of them.


About the Author Paul Cathro

Paul is an ex-HVAC engineer with 5 years 'in the trade'.

He acquired in 2022 and aims to make it the internet's most comprehensive HVAC resource for small homes in the next few years.

You can learn more about Paul's story here.

Browse his published work on the website here.

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