Why Won T My Chimney Draw

A wood burning stove needs sufficient draw to ensure continuous airflow through the stove in order for the fire to keep burning through the wood.

A wood burning stove that isn't drawing can lead to a fire that won't catch alight, won't stay alight, won't burn the wood properly or keeps smoking.

We've had issues with our wood stove not drawing over the years and so I've put together this guide on the reasons why your wood stove may not be drafting properly.

The main reasons why your wood stove does not draw can include:

The stove or flue is too cold.
The flue or chimney is dirty.
The room or house is too airtight.
The air vents aren't open enough.
The damper is closed, or closed by too much.
The wood is too wet.
The weather is too windy or warm.

There are also a number of things you can do to help with the draw on your stove, without the need to change anything structural in your home.

The main ways to increase draft in a wood stove include:

Have your flue or chimney cleaned at least once per year, or every season if you're regularly burning wood.
Leave the door to the stove open for a while before lighting a fire.
Warm flue with a heat source before starting a fire.
Leave the air vents wide open when starting a fire, and close them down as the fire progresses without causing the fire to smolder or go out.
Open the stove damper before lighting a fire, and leave open for the duration of the fire unless required to close it down.
Ensure to burn only dry wood.
Open a window or air vent near the stove.
Don't use your stove in very windy weather conditions.

I've explained the main reasons why your wood burning stove or chimney isn't drawing in more detail below, and also given solutions to each.

Why Does My Wood Stove Not Draw?

The Stove Or Flue Is Too Cold

If your flue or stove is too cold, or the same temperature as the air outside, it can affect how well the stove is drawing.

A draft works by colder air sucking warmer air towards it. As such, warmer air within your stove or flue will naturally rise up the flue, while also sucking fresh air into your stove from your home to replace the lost air.

If you're struggling to light a fire in your wood burning stove or keep it going you can help to warm up the flue prior to lighting a fire in your stove. We like to leave the door to our stove open for a while before starting a fire to help bring the stove and flue nearer to room temperature.

Stove Glass Clean — Leaving a wood stove door open before lighting a fire can help increase the draft

If your flue is still cold you can use a heat source to help bring the temperature up and start the draft on the stove.

We use a rolled up piece of newspaper that's lit at one end to help warm up the flue in our own wood stove.

Using a heat source such as lit piece of newspaper can help improve the draft on your wood stove

If you can see smoke from the newspaper rising up the flue then there's probably sufficient draw on your stove to be able to light a fire.

Seeing smoke from the newspaper rising up the flue is a sign of a good draft

For my complete guide to warming up the flue of your wood burning stove, click here.

The Flue Is Dirty

A flue that is dirty or blocked can be a reason why your wood burning stove isn't drawing.

The flue needs to be sufficiently sized in width and length to be able to provide the required draft on the stove. A flue that is dirty or blocked can result in a reduction of the diameter of the flue, and therefore the ability for it to suck air out of your stove.

Therefore, ensure that to get your flue swept if it hasn't been cleaned within the last 12 months.

It's recommended that a chimney or flue is swept at least once per year, ideally before your burning season. If you regularly or continuously burn wood inside your stove then you should have it swept every season to ensure that your stove is operating efficiently.

To help keep your stove and flue clean, be sure to only burn dry wood that is low in moisture content. Wet wood can release more tar (creosote) in a fire because it will be burning inefficiently as the fire tries to burn off the excess moisture content.

Be sure not to close any air vents on the stove down by too much, as a lack of oxygen can also lead to an inefficiently burning fire.

A poorly burning fire (one that is smoldering) due to lack of oxygen or wood that is too wet is likely to produce more smoke and tar, and can result in you needing to have your flue cleaned more often because your wood stove isn't drawing.

You can find out more about how often your flue needs cleaning and why in another article here.

The Room Is Too Air Tight

A wood burning stove that isn't drawing properly can be due to a room or home that is too air tight.

Air that's lost up the flue needs to be replaced from the air within your home through the stove's air vents. If your home is too airtight, then a vacuum can be created and your wood stove may not be able to draw properly.

For more modern homes that are built to higher standards, it's common to see a vent installed along with a wood stove to ensure that it has a consistent supply of fresh air for the fire.

If your room has an air vent, open it before starting a fire in your wood burning stove to ensure that there will be enough air circulation for the duration of the fire.

Fireplace Vent — Opening an air vent or window in the room can help increase the draft of on your wood stove

To help with airflow, you should also leave any doors to the rest of your home open while having a fire. If your wood stove still isn't drawing properly, try cracking open a window near your wood stove, or turn of any external ventilation extractor fans within your home that may be sucking air out.

The Air Vents Aren't Open Enough

When the door to your wood burning stove is closed, air can only get to the fire through the stove's air vents. If the air vents aren't open enough, it can restrict the draft on the fire, and therefore how efficiently the fire is burning.

Fully closed air vents will cause the fire to go out. Leaving the air vents wide open will allow maximum airflow into the stove and lead to the fire rapidly burning through the wood with large sized flames.

To help a stove burn wood more efficiently, the air vents on the stove should be closed down to a point where the fire is burning through the wood a steady pace, without causing the fire to struggle and smolder.

Air vents that are too far closed can cause the same effect as a blocked flue, where the wood stove isn't drawing properly.

Smoldering Fire — A smoldering fire can mean it's time to open up the air vents

Therefore, ensure that the air vents on your stove aren't closed by so much that it's causing the fire to burn the wood ineffectively.

The Damper Is Closed

If your wood burning stove has a damper (typically located in the stovepipe just above the stove) that is closed or closed by too much, it can prevent your stove from drawing properly.

Dampers can be used to reduce the amount of heat being lost up the flue, and can generally be found on older models of wood stove. A damper can be closed when the stove isn't in use to help with heat loss from a home, but needs to be fully open prior to starting a fire.

Therefore, if your wood stove isn't drawing, ensure that the damper is wide open before lighting a fire in your stove, and ensure that it isn't closed down by too much during a fire.

You can find out more about dampers, where they are located and how to use them in our complete guide to dampers here.

The Wood Is Too Wet

Wet wood is a common cause of many issues associated with a wood burning stove. Wood that isn't dry enough is harder to burn, and so can prevent a fire from catching and getting going.

Heat from the initial fire after lighting helps to start the draft on the stove, and to ensure that the remainder of the fire is more successful. If wet wood is preventing a fire from catching then it can prevent your wood stove from properly drawing.

Wood should be around 20% moisture content, and using a moisture meter will help you determine it's actual moisture content.

Windy Or Warmer Weather

Using your wood burning stove in windy weather can cause a backdraft where the wind forces the air back down your flue. If you're finding that your wood stove is struggling in windy weather then the only real solution is to wait for until the winds have subsided.

Warmer weather can also affect how well your wood stove is drawing. There needs to be sufficient pressure difference between your stove and the outside air for your stove to draw well.

Other Reasons

If you aren't able to improve the draw on your wood stove using the above methods then there may be issues regarding the size of your flue and chimney.

In general, the taller your chimney, the better the draft that can be provided on your stove. A chimney also needs to be higher than the roofline of your house (and other nearby buildings) in order for the draft to be sufficient enough for a fire in your home.