A Complete Guide to Flue Liners For Your Stove

A lot goes into installing a stove - once you have chosen your favourite style, you’ve then got to make sure you have all the parts in their right places!

Flue liners for wood burners are one of the most important pieces of the puzzle. Something of the back bone of your stove, they are responsible for making sure you can burn your fuel effectively and safely.

But, you may be wondering exactly what a flue liner is and if you really need one at all. In this guide we will cover:

What exactly is a flue liner?
Why you need to get your chimney lined
How to find out which size, type and length you need to buy
Approximately how much it will cost

Read on to find out everything you need to know about stove flue liners with our expert guide!

What is a flue liner?

First things first, what exactly is a flue liner?

A flue liner is just what it sounds like! Also often referred to as a chimney liner, a flue liner is a flexible tube that is connected to your stove pipe to line the inside of your chimney. It runs up the entire length of your chimney, carrying the fumes up your flue liner instead of releasing them straight into your chimney cavity.

How do I know if I have a chimney liner?

If you are using your chimney for the first time, you should have it inspected by a professional - this is to ensure it is operating safely, with no leaks or blockages. A chimney inspector will be able to tell you whether your chimney is lined, and if your liner is in good enough condition to use.

What is the purpose of a flue liner?

The main purpose of a flue liner is to:

Increase efficiency
Help keep your chimney clean
Improve safety

Of course, these three reasons are all very much connected!

First, let’s look at efficiency. Old unlined chimneys are generally cold, since they lack insulation. This makes it harder for the hot smoke to rise, so it will often condense before it reaches the top of flue. This can lead to water vapour forming - which can lead to damp - along with heavier smoke being produced.

This leads us to cleanliness. The more excessive smoke will dirty your chimney walls in the form of creosote. Creosote is incredibly hard to remove, so as it builds up it can create blockages.

Finally, this becomes a safety issue. Blockages are a very common cause of chimney fires. A lined chimney also helps protect you from carbon monoxide leaks. If any cracks form in your chimney that you are unaware of, dangerous fumes can leak out. A flue liner offers increased protection against this happening.

Do I really need a chimney liner for a wood burner?

We’ve seen the reasons in favour of them, but is a chimney liner really necessary for a log burner? After all, there are no laws that specifically say you must have your chimney lined, so long as you meet the requirements of Document J building regulations.

Firstly, you need to be aware that a chimney liner is not to be used in place of a suitable chimney - if your chimney is damaged, you will still need to get it repaired even if you have a chimney liner.

Secondly, while not mandatory, flue liners are highly recommended by most stove installers, and for good reason.

Along with offering improved safety, cleanliness and efficiency, one of the main benefits of fitting your stove with a flue liner is also better performance. Pretty much all log burners perform better with the help of a flue liner - you will experience less issues with draw, drafts, lighting your fire and keeping a good burn going.

So, while you can install a log burner without a flue liner, it is best not to. A flue liner will serve you well in the long run by protecting your chimney and saving you money from repairs that may result from not using one.

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What size flue liner do I need?

While it is not a legal requirement to have your chimney lined, if you do choose to do so, then there are regulations you must follow to make sure you do it safely. One of these is the size of flue liner you use with your stove.

If you are buying a new stove, the manufacturer should state what size flue liner to use with it. Always use the recommended flue size for your specific log burner - never use one smaller than required, as this is a serious safety hazard.

The general rule is as follows:

For a stove of up to 20kW a minimum of 6” diameter flue is needed.
You can use a 5” diameter flue liner if you have a DEFRA approved stove and the manufacturer clearly states this is compatible.

The size of the stove collar does not necessarily correspond to the size of flue liner you need. If your stove collar (where you attach the stove pipe) is 5” but you need a 6” flue liner, adapters are available for you to do so.

When it comes to length, you need to ensure you have a flue liner long enough to reach from the top to the bottom of your chimney. Sticking two separate pieces together is against regulations - and unsafe - so it’s better to order too much than too little! A chimney sweep should easily be able to measure your chimney length for you - just make sure you let them know you want it doing before they start the sweep.

To make things easier, when you order a flue liner pack with your stove from Direct Stoves, we ensure you receive the correct diameter liner and necessary adapter - just choose from the drop down when ordering your stove!

See our flue parts & adapters to find what you need to connect your liner to your stove.

What type of flue liner do I need?

Back in the 1960s, chimneys were lined with clay. Today, most chimneys are being lined with flexible steel liners. For a solid fuel burning stove, make sure you choose the right type - don’t use one intended for a gas fire or stove, as it won’t be safe.

There are two different grades of flue liner:

316 grade - this is cheaper but fine to use if you are burning seasoned wood only
904 grade - more expensive but also more durable. You should use this grade if you plan on burning coal frequently

How Much do Chimney Liners Cost?

The cost of lining your chimney is very much dependent on what diameter flue liner you need, how long you require it and what grade you go for.

For example, our 5” diameter 316 grade Dura Flue would cost around £102 for 6 metres.

Our 6” diameter 904 grade Dura Flue would cost around £181 for 6 metres.

A tradesperson could charge around £100 - £250 per hour to carry the work out, as they may need to bring safety scaffolding - plus, this is a two-person job! You might also need to factor in a cost of £50 - £80 for a chimney sweep first, if this is not included by your fitters.

Overall, fitting a chimney liner to use with your stove is a wise decision! It is:

Safer
More efficient, and;
Cleaner

Shop Flue Liners at Direct Stoves!

At Direct Stoves, we can source any parts you need to fit your log burner safely. Take a look at our flue liners for wood burning stoves to find quality products today!

Find more stove installation advice on the Direct Stoves blog…

Why You Need to Sweep Your Chimney | How to Have a Wood Burning Stove Without a Chimney | Why Does My Log Burner Keep Going Out?