There are many pictures on the internet showing a wood burning stove looking nice inside a clean and tidy inside an open fireplace, but not many pictures show the inside of a wood stove.
To show in more detail what’s happening behind the doors of a stove, I went to see my parents to take a load of photos of their wood burning stoves.
My parents have quite different looking stoves and both function in different ways, and so I’ve put this article together to share what it really looks like inside a wood stove.
So what’s inside a wood burning stove?
A wood burning stove typically contains:
- A firebox
- An ash tray
- A flue collar
- A baffle
- A door with a seal
- One or more air inlet vents
Keep reading to see pictures and explanations to each of these parts inside a wood burning stove, complete with two real world examples of stoves.
The firebox is the main part of the wood burning stove, where the fire is built and where further logs are added throughout the duration of the fire. It’s the area that you look into through the glass door to watch the embers burning and the flames flickering.
Every wood burning stove has a firebox (otherwise there would be nowhere to burn the wood!), and so here’s pictures showing the fireboxes in my parent’s stoves:
You’ll also be able to see in the images above that the firebox is surrounded by a fireproof material that helps to protect the outer unit of the wood burning stove from the heat of the fire. This material is typically made from firebricks or ceramic.
In one of the wood burning stoves this material also forms the base of the firebox, while the other stove has a metal grate at the base of the firebox.
An ash tray, also known as an ash pan, collects the leftover embers and ash from a fire to help you dispose of them more easily, and is typically located underneath the firebox.
Interestingly, only one of my parents has an ash tray in their wood burning stove. My dad’s ash tray is located underneath the firebox, while my mother’s stove doesn’t have an ash tray at all.
Here’s a photo of a wood burning stove ash tray that has been pulled out:
There is a grate at the base of the firebox which can be turned using a knob on the side of the stove to help drop the leftover ash into the tray. By pulling the knob in and out, the grate rotates and shakes the ash into ash tray.
On the other hand, our other wood burning stove doesn’t have an ash tray and so the leftovers from a fire must be brushed into a pan before being disposed of.
Leaving a bed of ash is an important part of using your wood burning stove, and can help prevent damage to your stove and help get the fire going. You can find out how much ash you should be leaving in your wood burning right here.
Waste gases and smoke from a fire leaves wood burning stoves via a flue, which is connected to the stove via a flue collar.
In my parent’s wood burning stoves, both of the flues and the outlets of the stoves are located at the top of the stoves.
In these models of wood burning stoves, the flue goes vertically out of the stove and up the chimney. The chimneys are lined with stainless steel pipes that take waste gases from the stove straight to the top of the chimney.
The base of the chimney is capped to prevent any airflow going up the chimney apart from the air that is going through the wood burning stove.
The outlets of the wood stoves are located behind baffles, which are plates located at the top of the stove to prevent waste gases from the fire from leaving the stove too quickly.
By slowing down how quickly gases leaving the stove, more time is provided for secondary burn of the gases, and the stove can therefore produce more heat as a result.
A baffle also helps to reflect and radiate more heat back into the firebox for a better secondary burn of the gases.
Here’s what the baffle looks like in my dad’s wood burning stove. It directly blocks access to the flue above and so gases have to make their way around the baffle to leave the stove.
The baffle is located just above the fire and therefore the hottest part of the stove. Not only does a baffle play an important role in burning waste gases to produce more heat, it has to deal with extreme temperatures.
You can see that the above baffle plate has been subject to intense heat and may have to replaced after more years of use. Over firing your wood burning stove can damage the baffle plate, and you can find out more about over firing here.
Doors With Seals
When opening the door of a wood burning stove, you’ll typically see a seal around the edge of the door that helps to prevent any airflow through the sides of the doors when closed.
On one of the wood burning stoves you can see that the stove door is double sealed, while the ash tray compartment is also sealed when the door is closed. The other stove only has one seal on the door.
The seal is usually made from fiberglass rope, which is fire proof and heat resistant.
Most wood burning stove’s can’t function efficiently with the door open, and so the seal around a stove door allows the airflow into the stove to be more easily controlled through only using the stove air vents. You can find out more about leaving your stove door open during a fire here.
The air vents on a wood burning stove can be used to control the flow of air into the stove, and help control the rate at which the fire burns through the wood. You can read more about primary, secondary and tertiary air here.
My dad has both primary and secondary sets of air vents on his wood burning stove. The main (primary) vent is located located near the bottom of the door, and is controlled by turning the vent plate. This primary vent can be seen on the inside of the door.
The secondary air vent is located underneath the stove and is controlled by a handle located just underneath the door. The secondary vent can’t be seen from within the stove. Air flowing through this vent helps to prevent the blacking of the glass on the stove door.
In comparison, my mother’s wood burning stove only has one set of air vents located on the bottom of the stove, and is also controlled by a handle located at the base of the stove door.
There’s no secondary set of vents for airwash on the stove and so the stove glass door is prone to blackening.
Air vents play a very important part in how efficiently a wood burning stove gives off heat from burning wood, and using the air vents incorrectly can be a reason why the fire in a wood burning stove keeps going out.
In order to get the most heat out of a wood burning stove it’s important to understand what primary, secondary and tertiary air is, and their purpose. More info about each type of air flow in a wood stove can be found here.
Other Parts Inside A Wood Burning Stove
Other more modern and more efficient wood burning stoves than my parent’s stoves may also include a catalytic converter that helps to remove pollutants from the air that leave the stoves.
Wood burning stoves can also have a damper located within the flue which helps to control the draft on the stove from the flue. Too much draw and the waste gases can be removed from the stove too quickly, preventing secondary burn of gases from occurring properly.
Some wood stoves also have a blower incorporated that helps to spread the heat around the room.
You may also like to read the 18 things we had to consider before we bought our wood burning stoves, and the reasons we bought our stoves.
This didn’t answer all my questions. However, it was an extremely informative and well written article. Thank you.