Thursday, October 6

How Do Pellet Stoves Work?

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Thanks to their ease of use, incredible efficiency and the fact they require very little maintenance and operation, pellet stoves are becoming a popular choice for home heating. But, how do they work? Keep reading and the Direct Stoves team will tell you everything you need to know…

What are the main parts of a pellet stove? 

Like any appliance, it’s best to have a firm grasp of the different parts and components a pellet stove is made up of, in order to understand how it works. 

So, below we’ve detailed the main parts of a pellet stove and what they do. 

Hopper (fuel container)

As the name suggests, a pellet stove requires a source of pellets to burn. 

These pellets are stored in what’s called the ‘hopper’. This is essentially an area that pellets are poured into, and will have sloping sides. This helps the pellets to move down through the hopper when they are required.

Depending on the model of pellet stove that you select, the hopper can be situated at either the top or bottom of the stove. 

In our experience, hoppers situated at the top of pellet stoves (known as top-fed hoppers) perform best, as they can use gravity to assist with the feeding of pellets to the auger.

Wood pellets for pellet stoves

Auger 

Resembling a long screw, the auger is a motorised device which helps deliver pellets from the hopper to the combustion chamber. 

As it spins it helps pull pellets down from the hopper, along the auger to the end, where they drop into the combustion chamber.

The auger is a particularly important part of a pellet stove, as it is the part which helps to control the temperature of the combustion chamber (and thereby the temperature of the pellet stove as a whole). 

It does this by varying its speed. If the sensors in the combustion chamber sense that the fire is not burning enough to maintain the required temperature, the auger will ‘speed up’, thus depositing more pellets in the combustion chamber. 

Likewise, if the fire is getting too hot, the stove’s sensors will tell the auger to slow down, thus depositing fewer pellets into the combustion chamber. 

Combustion chamber (burn pot)

This is where the action happens (so to speak). The combustion chamber (also known as the burn pot) is where the pellets are actually burned. 

For those of an automotive disposition, you can think of the combustion chamber as a sort of carburetor for the stove, where air, fuel (the pellets) and ignition are mixed to create a fire. 

In many models of pellet stove, the combustion chamber (or the flue exiting the chamber) will be fitted with electronic sensors. These will monitor the temperature within the chamber (or the gases exiting the flue) and instruct the auger to deliver more or fewer pellets as required. 

This helps to ensure a consistent burn and temperature within the combustion chamber. 

Note – you may want to clean the combustion chamber every so often, so look for pellet stoves which feature extractable combustion chambers/burn pots.

Ash pot

Wood pellets are very dense and as such, give off a large amount of heat whilst burning cleanly.

However, they do still produce a small amount of ash.

In most models of pellet stove, this ash is deposited in an ash pot. This often takes the form of a drawer which sits at the bottom of the stove. This drawer can be removed by hand to make disposal of the accumulated ash easier. 

Convection blower

Pellet stoves heat rooms using convection. They tend to do this using a convection blower which pulls cool air from the room into the stove. 

This cool air is passed over a heat exchanger which sits on top of the combustion chamber. This heats the air as it passes over. This clean heated air is then released out into your living space, warming it up. 

Distribution blower

Some pellet stoves aim to assist the process of convection by using what’s called a distribution blower.

This is simply an internal fan which helps push air out into the room once it has been heated up by the heat exchanger.

Note – in some pellet stoves, the convection blower will both pull in fresh air and help distribute the heated air (thus doing both jobs). Some models of pellet stove will include both a convection and distribution blower. It’s because of this overlap that you’ll sometimes see the terms convection and distribution blower used interchangeably.

Exhaust blower 

All of the smoke and combustibles produced by the combustion chamber have to go somewhere… So, it’s the job of the exhaust blower to push the smoke and combustibles generated by the fire out through a duct at the rear of the stove.

It’s important to note that this duct needs to pass through an exterior wall of your home and vent out into the open air. As you would expect, this will influence where you can locate your pellet stove in your home.

La Nordica Serafina Pellet Stove

La Nordica Serafina Pellet Stove

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Thermostat and sensors

It’s the thermostat and sensors that make pellet stoves such convenient, modern heating appliances. 

The thermostat and sensors are usually placed around, or near the combustion chamber or its flue, where they can effectively monitor the temperature of the fire and request more or less pellets as required. 

The types of sensors typically found in pellet stoves, include: 

  • Temperature sensors – located around or near to the flue outlet, measuring the temperature of the exhaust gases.
  • Pressure sensors – often located in or near to the combustion chamber to measure the air pressure being maintained. 
  • Temperature sensor – used to measure the temperature of the room in which the stove is placed. The readings from this sensor are used to modulate the fire in the stove.

It’s thanks to these thermostats and sensors that pellet stoves are so convenient and easy to use compared to traditional wood burning stoves. With many models, you can pretty much ‘set and forget’ them and they’ll burn throughout the day automatically.

Controls

Pellet stove manufacturers have made a concerted effort to make their stoves user friendly and easy to set up, use and control. 

As such, most pellet stoves will come with a control panel, which is usually situated on the top of the stove. Many control panels will include an LED/LCD display, so you can clearly see what you are doing. 

Most of the components in a pellet stove will be automatically controlled. This helps to eliminate user error and ensures that your stove maintains the correct fuel to air ratio to create an efficient burn. 

The components that are usually automatically controlled, include: 

  • Auger. 
  • Convection blower.
  • Distribution blower.
  • Exhaust blower.

Most pellet stoves with automatic controls will allow you to manually change the settings as well. That way you can easily change settings such as:

  • The times of day that the pellet stove turns on and off. 
  • The days of the week that it operates. 
  • Room temperature.

Some of the most advanced pellet stoves are also coming with extra control features such as smartphone control. This means you can remotely control your pellet stove using your smartphone. 

Flue

As we mentioned earlier, pellet stoves do produce exhaust gases from the combustion chamber. So, you will need to make sure they are safely vented outside of your home. 

Not all pellet stoves will come with a flue, so it’s important that you give this some thought when you are making your purchase. 

Luckily, because pellet stoves are forced-induction appliances, the exhaust gases can be safely vented horizontally from the rear of the stove. This means that you’ll only need to run a short flue through an external wall of your home (as opposed to having to create a vertical flue running up through your home and out of the roof). 

Note – some pellet stoves feature their flue outlet on the rear or top only. Others will have flue outlets on both the top and rear, so you can choose the most convenient option for your home.

Power cord and plug

It’s easy to overlook the fact that pellet stoves are electrically powered appliances. 

They need to be plugged into a nearby electrical socket and turned on before you can start burning wood pellets in them. 

So, every pellet stove will come with a power cord and plug.

There you have it. Those are the fundamental parts of a pellet stove. It’s these components that come together to make a pellet stove function. 

La Nordica Amika Pellet Stove

La Nordica Amika Pellet Stove

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How pellet stoves work

Now that we have a firm understanding of the main components of a pellet stove, let’s take a look at how a pellet stove works. 

Powering up

Before you can do anything with a pellet stove, you need to plug it in and press the power button. 

On many pellet stoves, the LED/LCD screen on the control panel will light up to indicate that the stove has turned on.

Fuelling up

The next step involves filling your stove up with pellets. 

On many pellet stoves the hopper (fuel container) is located at the rear or top of the appliance. 

Adding the pellets involves either opening the lid to the hopper (if it has one), or simply pouring the pellets through a grill into the hopper.

The volume of wood pellets you can add will be determined by A) how long you want the pellet stove to burn for, and B) the capacity of the hopper. 

It’s difficult to provide an average capacity of pellet stove hoppers. It really does depend on which model you select. 

Smaller pellet stoves have hoppers that can hold around 35 pounds (15 kilograms) of pellets, whereas larger stoves have hoppers that can hold up to 130 pounds (58 kilograms) of pellets.

Starting up

This is a difficult point to write about as different pellet stove manufacturers have different start up procedures. 

In general however, pellet stoves can be divided into two types: 

  • Pellet stoves with automatic ignition. 
  • Pellet stoves with manual ignition. 

If you have a pellet stove with automatic ignition, then you simply need to press a button on the control panel and the pellets in your stove will be ignited and start to burn.

In the event that you have a manual ignition pellet stove, then you’ll need to use a gel or solid starter material in order to ignite the pellets. 

Note – always follow the manufacturer’s exact ignition and start up instructions.

Feeding the fire

Once your pellet stove is on and has been ignited, the auger will start feeding the fire in the combustion chamber with pellets. 

As you’ll have seen earlier, most pellet stoves use a motorised screw auger. These tend to be gear driven and are located within the hopper. 

As the screw turns it ‘pulls’ pellets down the hopper. 

Once the pellets reach the bottom of the hopper, they fall down a chute into the combustion chamber. 

As we mentioned earlier, the auger will turn faster or slower depending on the amount of pellets required in the combustion chamber. The speed of the auger is determined by a thermostat and/or sensors which provide instructions to the auger.

The operation of the auger is entirely automated.

The fire

The fire will be burning in the combustion chamber at this stage. Many pellet stoves feature a large viewing window, so you and your family will be able to enjoy the sight of a real fire in the heart of your home. 

Depending on the settings you have put in place, the stove will burn for the length of time and at the temperature that you have set.

As all of these factors add up to make pellet stoves almost as easy to use as gas and electric fireplaces – but with far more character!

The heat

With the fire burning away inside the pellet stove, heat will begin to build up in the combustion chamber. 

But, how do pellet stoves get this heat out safely into your living space? 

Well, they use some of the components outlined earlier. 

Pellet stoves will draw their air supply either from the room in which they are situated (or from outside of your home via an external air duct). 

Regardless of where they source their fresh air from, they do so using a convection blower. This ‘pulls’ fresh air into the pellet stove and passes it over a heat exchanger located on top of the combustion chamber. 

It’s this heat exchanger which transfers heat from the combustion chamber, to the air passing over it, heating it up. 

This newly heated air is then released from the top of the stove into your living space, rising and filling the room via the process of convection. Some stoves will use an internal distribution blower to assist this process.

The exhaust gases

Generating this heat also generates waste gases such as smoke and combustibles. 

In many pellet stoves, the exhaust gases are pushed out the flue with an exhaust blower. These exhaust blowers actively draw the air out of the combustion chamber and down the flue. 

Some pellet stoves also feature baffle plates around the top of the combustion chamber. It’s the job of these baffle plates to slow down the rate at which air leaves the combustion chamber. This helps to create the ideal air pressure within the chamber which results in a highly efficient burn. 

Shutting down

Once your room is sufficiently heated, you may want to turn off your pellet stove (unless you’ve already pre-programmed it). 

Unfortunately, we cannot provide you with universal instructions on how to turn off a pellet stove.

Each particular model is different. So, when it comes to turning off your pellet stove, please refer to the manufacturer’s instructions. 

Duroflame Rembrand Plus Pellet Stove

Duroflame Rembrand Plus Pellet Stove

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Pellet stove maintenance 

Now you know how a pellet stove works. Great! But, we know that some of you may want to know how much maintenance is involved with pellet stoves.

Well, handily, the answer is not a lot!

The small amount of ongoing maintenance required for pellet stoves is one of the key reasons they are becoming so popular.

You get all of the character, functionality and aesthetics of a traditional wood-burning stove, but with far less hassle. 

Nevertheless, there are a few things you should do on an ongoing basis to keep your pellet stove in top condition. 

Ash removal

We mentioned earlier that pellet stoves produce very little ash. And, that’s correct! But, it still means you should be removing what ash they do produce every so often (particularly during the winter months when you’re using the stove a lot). 

Many modern, high-quality pellet stoves feature a handy ash pot or drawer. So, removing the ash is as simple as pulling out this drawer and disposing of the ash.

Combustion chamber cleaning

Like anywhere where fire is burnt, the combustion chamber is likely to build up ash, detritus and other bits and bobs. 

So, you’ll want to clean the combustion chamber on a regular basis too, especially if you’re using the stove a lot during the colder months of the year. 

Annual inspection

It’s advised that you have your pellet stove inspected and cleaned on an annual basis. 

It’s entirely possible to do this inspection yourself by following the manufacturer’s instruction manual, but if you prefer there are heating engineers who will be able to do this inspection for you. 

An inspection involves checking the main components of the stove such as the auger, auger motor, hopper, switches, blowers, controls and seals. 

Popular pellet stoves UK

We hope you’ve found our guide to the operation of pellet stoves useful. As you can see, they are fantastic appliances which are not only highly efficient, but convenient and easy to use and packed full of character.

It’s easy to see why more and more people in the UK are choosing pellet stoves to heat their homes. 

If you think a pellet stove would make a great addition to your home, then check out some of our most popular models here at Direct Stoves. 

La Nordica Luisella Pellet Stove

La Nordica Luisella Pellet Stove

La Nordica Luisella Pellet Stove

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Producing up to 4.4kW of heat, the La Nordica Luisella is a powerful, yet highly-efficient pellet stove, producing the perfect amount of heat for smaller living rooms or other compact living spaces. 

La Nordica is one of the leading pellet stove manufacturers and it certainly shows in the design and quality of the Luisella. 

Available in your choice of either a black or black and burgundy finish, the Luisella features a reduced depth design, meaning it takes up minimal floor space, has a 5-button remote control, and is rated A+ for energy efficiency. 

Duroflame Rinus Pellet Stove

Duroflame Rinus Pellet Stove

Duroflame Rinus Pellet Stove

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Designed and crafted in the heart of the Netherlands, the Duroflame Rinus is a pellet stove that marries classic design touches with the latest technology. 

With a maximum heat output of 7.3kW, the Rinus has more than enough power to heat large living rooms or open plan spaces. 

This power is matched with convenience in the form of an easily programmable thermostat and an easy to use, hidden from view, control panel.

The Rinus also has great green credentials with an efficiency factor of 85.7%.

La Nordica Teodora Evo Pellet Stove

La Nordica Teodora Evo Pellet Stove

La Nordica Teodora Evo Pellet Stove

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Pellet stoves may be sleek, modern heating appliances, but it’s still possible to buy models that feature the classic stove ‘look’. 

The Teodora Evo from La Nordica is just such a pellet stove. 

Thanks to its baroque styling, the Teodora Evo will make an arresting and eye-catching addition to even the grandest of living rooms, libraries or studies. 

You’ll be reassured to know that the Teodora Evo’s traditional styling doesn’t come at the expense of modern technology and efficiency. The included remote control is the first evidence of that point. 

It’s a pellet stove that’s up there with the very best in terms of efficiency, with a performance factor of 94%, and an energy rating of A+. 

That efficiency doesn’t reduce the stove’s performance in any way. The Teodora Evo is capable of an 8kW heat output, meaning it’s perfect for heating the largest of living rooms. 

Help is at hand!

Have you got any questions that you’d like answering before you make the leap into the world of pellet stoves? 

Then the Direct Stoves team is more than happy to help. 

We can provide free advice and information about any of our pellet stoves. Simply call 0161 516 9601 or email [email protected].

Video survey service

We know that buying a stove online can sometimes be a bit of a challenge. What will it look like in your own home? Will it fit in your fireplace? Will it go with the rest of my home’s decor? 

These are all questions that can nag away at the back of your mind prior to a purchase. 

Well, Direct Stoves can answer all of these questions and more with our free video survey service. 

We can arrange for you to have a video consultation with one of our stove fitting specialists. They can let you know if your home can accommodate a stove, and if so, what type would be best. 

Find out more about our stove video survey service now.

Choose Direct Stoves

If you want to buy the best pellet stove at the best price, then buy one from Direct Stoves. 

Not only are we the UK’s biggest online retailers of stoves, but we offer fantastic benefits such as free mainland UK delivery, 14-day no hassle returns and a range of finance options to help you make your dream stove a reality. 

Shop pellet stoves at Direct Stoves now

For more stove buying guides, advice and information, read the Direct Stoves blog

Pellet Stove Buying Guide | New to Direct Stoves: Pellet Stoves | How to Heat Your Home Without a Gas Boiler: A Guide to Back Boiler Stoves

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