Pellet stoves are a more complex form of stove compared to wood burning stoves.
Pellet stoves have a whole host of internal components designed to help them burn fuel as cleanly and efficiently as possible and produce the most amount of heat with the lowest emissions.
Our own pellet stove has far more parts compared to our wood burning or multi fuel stoves and so we’ve put together this article to explain all of the parts of a pellet stove.
Parts commonly found in a pellet stove can include:
- Combustion chamber
- Auger & gear motor
- Fuel delivery chute
- Fume extractor with combustion blower
- Flue socket
- Air intake vent
- Distribution blower
- Heater outlet
- Heat exchanger
- Power cord & switch
- Control unit with screen
- Burn pot
- Ash tray
- Ignition system
- Baffle plates
- Glass door
We’ve explained all of these parts in greater detail below showing what they look like on our own pellet stove.
The body of a pellet stove is relatively large as it needs to hold a range of components and also store the fuel in the form of pellets inside as well as providing enough storage for a day’s worth of burning.
The images below show what our own particular model of pellet stove looks like from the front, back and top and the main components labelled.
Much of the body of a pellet stove hides the components inside and on our stove only a small area constitutes where the fire is actually located.
The combustion chamber of a pellet stove is where the fire is located.
On our particular pellet stove, the combustion chamber is located at the front middle of the unit.
In the case of our stove, the combustion chamber can be accessed by opening the door fronting it. It’s a fairly narrow but tall area and it’s here that:
- The fire is started using the ignition system.
- Fuel is supplied from the hopper storage area.
- Fresh air is supplied to the fire from below.
- Waste air is sucked out from the top of the combustion chamber.
- Ash is collected at the bottom of the chamber.
We discuss some of the main parts of a combustion further in this article.
The hopper of a pellet stove is where the fuel in the form of pellets is stored before being delivered to the combustion chamber for burning.
Unlike other forms of stove where the fuel needs to be manually added to the fire, pellet stoves automatically deliver their fuel to the fire and so the fuel needs to be stored within a pellet stove in an area known as the hopper.
The hopper on our pellet stove is located at the top of the unit and can be accessed by removing the cover.
Fuel for pellet stoves come in the form of pellets, which can typically be bought in bags of certain weights. The bags of pellets we buy typically come in 15kg weights (33lbs) but can also be commonly found in 40lbs.
These pellets can be added to the hopper of a pellet stove through the hatch. Our particular model of pellet stove has a grate across the hopper access to help stop the bag or any other items from failing in.
Pellets stoves automatically deliver pellets from the hopper to the fire in the combustion chamber using a motorized auger.
This auger will be located within the hopper itself and takes pellets from near the bottom of the hopper.
As the auger rotates it moves pellets higher up in order to fall into the combustion chamber via the pellet chute.
Augers in pellet stove are driven by motors and controlled from the central control unit to ensure that pellets are only delivered to the fire as an when required. The motor for the auger in our pellet stove is located beneath the hopper.
Fuel Delivery Chute
Pellets reach the fire in the combustion chamber from the hopper via the fuel delivery chute.
As the hopper in our particular model of pellet stove is located at the top of the unit, pellets fall from this area down into the combustion chamber through the chute.
The chute finishes just above the actual combustion area within the combustion chamber.
If we look up this chute from the combustion chamber we can see the top of the auger.
The fume extractor in a pellet stove contains the combustion blower that sucks waste air out of the combustion chamber in order for it to be removed from a home via the flue.
As the combustion chamber on a pellet stove is sealed, this in turn creates a vacuum which sucks fresh air into the chamber to feed oxygen to the fire.
The fume extractor in our pellet stove is located beneath the combustion chamber behind one of the front panels.
Waste air in the combustion chamber that is sucked out using the combustion blower in the fume extractor leaves the back of a pellet stove via the flue socket.
The flue socket will be a certain diameter (in the case of our stove its 80mm) and will connect up to the flue system that will remove waste air from a home.
Air Intake Vent
The fresh air that is sucked into the combustion chamber from the vacuum created by the fume extractor removing air will come into a pellet stove via the air inlet.
This air inlet is located on the back of our pellet stove near to the flue socket.
Fresh air travels from the inlet to the combustion chamber via a plastic tube in our pellet stove.
Pellet stoves use a distribution blower to force warm air out into the room through the front of the stove.
The distribution blower in our pellet stove is located just behind the lower back area of the combustion chamber.
The distribution blower shouldn’t be confused with the combustion blower, which is located within the fume extractor and removes waste air from the stove.
Air blown by the distribution blower will come out of the front of a pellet stove through the heater outlet.
The heater outlet on our pellet stoves comes in the form of a grille.
Cooler air blown by the distribution blower passes around the combustion chamber on the way to the heater outlet and heats up, therefore providing hot air to the room.
The heat exchanger helps transfer the heat generated from the fire inside the combustion chamber to the air that’s moving around the outside of the chamber from the distribution blower to the heater outlet at the front of the stove.
The heat exchanger doesn’t need to be anything fancy and in the case of our own pellet stoves comes in the form of a number of heatsinks, which can be seen when looking into the heater outlet grille.
Power Cord & Switch
Pellet stoves are electrical appliances and require a source of electricity in order to work. You’ll therefore find a power cord and switch on pellet stoves, typically located at the back.
The power cord on our particular model of stove came separate from the stove and so we simply needed to plug it into the back of the stove, plug the other end into a nearby electrical outlet and turn the mains switch on at the power unit on the stove.
The only exception would be if using a non-electric form of pellet stove. See our article on pellet stove electricity for more information.
Control Unit & Screen
In order for pellet stoves to achieve the higher efficiency levels that they do, all of the processes inside that help promote clean burning of the fuel need to be automatically controlled by a central control unit.
In the case of our pellet stove the control unit is located on the top of the stove.
It’s here where we can control all of the functions on the stove using the touch screen.
The burn pot is the actual combustion area inside the combustion chamber where the fire is located and where the fuel is added to from the hopper.
This combustion area in our own stove is relatively small compared to the size of the whole stove.
This burn pot can be removed from our stove for cleaning purposes.
Much like other forms of wood stove, a pellet stove will leave behind some wastage from the burning process in the form of ash, which falls out of the combustion area into the ash tray.
The ash tray is located at the bottom of the combustion chamber in our pellet stove.
It can be removed just like the burn pot for the purposes of disposing of the ashes and for easier cleaning.
The fire in a pellet stove is started by the ignition system.
The ignition system in our own pellet stove is located just behind the burn pot found in the combustion chamber. It can’t be seen, but the outlet can be found below where the burn pot sits.
Much like other forms of wood stoves, pellet stoves can have one or more baffle plates located at the top of the combustion chamber.
These help to slow down the rate at which waste air leaves the combustion chamber to aid in burning off any leftover waste gases to help produce even more heat and help further reduce emissions.
Our particular model of pellet stove has two baffles, one located above the other with space for air to flow in between the gaps at separate ends.
Removing this lower baffle plate highlights the other baffle above.
The baffle plates in our wood stove are made from vermiculate, while the baffles in our wood stoves are made from steel.
In order to help maximize efficiency, pellet stoves typically contain a number of sensors that help feed live information back the to the control unit that will adjust air flow and fuel supply accordingly.
Our particular model of pellet stoves has three sensors:
- A fume temperature sensor located within the flue outlet from the stove.
- A room temperature sensor located in the body of the stove.
- A pressure switch located in the combustion chamber.
The fume temperature sensor measures the temperature of the gases leaving the stove to understand how hot the fire in the combustion chamber is.
The room temperature sensor constantly measures the current room temperature to tell the stove whether the desired room temperature has been reached. The pressure sensor measures the current pressure within the combustion chamber.
Pellet stoves will have a glass frontage in which to view the flames through.
In the case of our pellet stove, this glass panel is integrated into the front door of the stove that provides us access to the combustion chamber when opened.
As pellet stoves are sealed systems for efficiency purposes, the back of a pellet stove door will typically have a gasket seal to keep the combustion chamber airtight when closed.
This gasket may need to be replaced every couple of years to ensure that the door remains airtight.
The handle on this door is metal and gets too hot to the touch during fires, and so we need to use the glove that come with our stove if we ever need to open the door after fires.