Infographic: What is a chimney liner and do I need it?
Infographic: What is a chimney liner and do I need it?
5 mins

Infographic: what is a chimney liner and do I need one?

Infographic- what is a chimney liner and do I need one for my wood burning stove?

What is a chimney liner?

A flue liner or chimney liner is a stainless steel flexible tube that is used to line the inside of a chimney in order to provide a robust and perfectly-sized passage for the combustibles from a solid fuel appliance (e.g. wood burning or multi-fuel stove) to evacuate a property in a safe manner.

What is the difference between a flue and a chimney?

The flue is the inside passage and the chimney is the overall structure. "If the chimney is a polo mint then the flue is the hole" works well to show the difference.

Houses built before 1968 usually had chimneys constructed of brick or stone. Houses built after 1968 had to have the brick or stone chimneys lined (usually with pot, pumice or similar). This improved the draw of the chimney due to improved insulation and a smooth passage for the gases. Whatever material a flue is created from its performance and safety can be improved by the addition of a flexible stainless steel liner tube between the stove and the very top of the chimney.

Chimney draw (the suck)

"But my old open fire never had a liner and the draw was enough to suck your slippers off!"

Open fires have a lot more draw than a modern stove because they are inefficient: modern wood burning stoves are generally 80%+ efficient (less than 20% lost heat up the chimney), compared to open fire stoves which are 15-20% efficient (80-85% lost heat up the chimney). Because hot air rises open fires have a high draw.

Still, do I really need to line my chimney?

Even though building regulations do not insist that you fit a chimney liner, it is generally recommended that you do line your chimney. Fit a chimney liner and there should be no reason for a stove not to perform as the designer intended. Highly efficient, modern solid-fuel stoves need all the help they can get in keeping that rising air nice and hot and travelling without interference from obstacles or turbulence.

316 or 904 chimney liner?

The terms 316 and 904 are grades of stainless steel with 904 being superior. For light use choose 316 grade chimney liner. For heavier use choose 904 grade chimney liner. If burning smokeless fuel always choose 904 grade. If unsure always choose 904 grade.

Consequences of not lining your chimney

Safety

If the chimney is not sound then smoke and carbon monoxide can travel into your (or next door's) property.

Performance

Hot air (smoke) rises because it is hot - cool it down and it will slow, stop or sink. Hot air does not rise well in cold chimneys, especially where heat-stealing voids or non-smooth surfaces are present as these steal heat and slow down the combustibles. A stove's performance is affected by the gases having a smooth route of passage.

Tar

These combustibles, when slowed, deposit tar and condensation both of which can damage properties; in brick/stone chimneys tar eventually bleeds through the mortar into the house, staining wall papers etc.

Smoke in room

If smoke slows down too much then the smoke behind dams up underneath and the stove burns poorly. With a poorly performing flue smoke can escape when the door is opened (to add fuel) or exit the stove via air vents designed to allow air in.

Chimney fires

Fires in liners are extremely rare and would be contained within the stainless steel tube. Modern solid-fuel stoves are very safe. The inclusion of a chimney liner and carbon-monoxide detector ensures maximum peace of mind.

Quick links on chimney liner and lining

What is chimney liner/flue liner (article)?

What is a chimney liner and do I need one (infographic)?

What can happen if I do not line my chimney?

The different ways of connecting a chimney to a stove (simple diagrams)

How to choose and measure for chimney liner (infographic)

Do I need to line my chimney?

Can I, should I, fit a 5″ chimney liner?

What grade of chimney liner? 316 or 904?

Should I insulate my chimney liner?

How to line a chimney with chimney liner

Fitting a chimney liner to a pot or cowl

Buy fitting packs (alongside liner and stove this is what finishes the job)

Stove to flue to adaptor to liner

Connecting a wood burning stove to a liner, inside fireplace opening (fitting a closure plate)

Connecting to a to liner, outside fireplace opening

Distance to combustibles

Chimney stack ends in a loft (somebody took it down)

Fitting a chimney pot

Access and safety when fitting liners (and some quick-build platform ideas)

FAQs

See all FAQs

Costs correct as of April 2023:

Approx. costs if you have a chimney and fireplace ready to use: £750-£1,000 (save £500 by self-installing).

Approx. costs if you have a chimney but need the fireplace "opening up": £1,600-£2,200 (save £1200 by self-installing).

Approx. costs if you do not have a chimney and need a clip-together flue: Shed £475-£700. Bungalow £1500. 2-storey house £2500. Save £1,000-£1400 by self-installing.

Above figures include labour and materials but no appliance.

We, of course, advise you to purchase your stove and materials from Stovefitter's to ensure quality goods are installed (some installers use budget materials to increase margin). If you buy your stove from us (rather than your local small shop or installer) we have a lot more power when approaching manufacturer's with a warranty issue. Why is that? Because we buy many hundreds of stoves a year from these brands.

We do not fit stoves.

But we know a few who do!

Google: Hetas installers

Hetas are the trade body of registered UK installers.

Most installations will require that you slide a chimney liner down your chimney (flexible metal tube 5" or 6" in diameter). Do you have a narrow chimney and want to lessen the risk that a liner might not go down your chimney? Then make sure your chosen stove can use a 5" liner.

Must I line my chimney? Best read this article but most likely the answer is yes. Do I have to fit a chimney liner?

DEFRA-Exempt wood burning stoves with a 5″ collar can usually be fitted to a five inch liner rather than the usual 6″ minimum, making the installer's job much less stressful.

ALL OF THE 5KW STOVES WE SELL CAN BE FITTED TO A 5" CHIMNEY LINER.

I seriously suggest any self installer fits a 5" liner unless they know their chimney is large enough for a 6"!

What is the best chimney liner? Silvacore 904 (we sell it so of course we will say that ;-). What is the best chimney liner?

Will your stove require an air vent within the room (some stone walls are very difficult to drill)?

5kW or under and wood burning stoves often do not require an air vent (new builds always require an air vent).

What is the maximum output in kW of your "5kW" wood burning stove? The majority of manufacturers just specify the “nominal output” and this figure means very little in real life. The nominal is a figure the manufacturer chooses to sell the stove at - the stove is capable of reaching at least this output with one fuel load. Nominal means "capable of". But it is not the maximum.

Check out the size of the area where the logs will go (firebox size) as this varies enormously. The kW output is completely dependant on the amount of logs burning at any one time - more logs burning equals more heat. If you can fit three logs in stove A and just two logs in stove B then stove A will be capable of throwing out 33% more heat.

DO NOT TRUST MANUFACTURERS’ kW RATINGS as manufacturers specify what output they desire to sell the stove at and testing allows for much “playing with the figures”. This is why you can get very small 5kW stoves (e.g. Aga Little Wenlock) and very large 5kW stoves (e.g. DG Ivar 5 by Dik Geurts which is actually rated 5kW but has a MUCH larger firebox than the Ekol Crystal 5 by Ekol Stoves). A Crystal 5k might get to 5kW and not be capable of any higher whilst a DG Ivar, despite being rated at 5kW, can get to 8kW with a full fuel load.

Note that, over time, one might damage the internal firebricks of a stove by running at a higher load than the manufacturer's suggest. Firebricks are easily replaceable.

Will your wood burning stove fit in your recess WITH the required air gaps around it? This is obviously not an issue if your stove will be freestanding.

Air gaps to non-combustible materials (brick, stone etc.) are usually "as close as you like" legally but manufacturers will sometimes specify a recommendation. This recommendation is there to allow heat to escape from the recess into the room - so you get the heat benefit rather than the heat soaking into the building structure and being lost. If no gap to non-combustibles recommended then we suggest 50-100mm air gap left and right of stove, 50mm behind and 100mm above.

Are you in a Smoke Control Area (usually built up areas)?

Choose your stove accordingly.

A stove must be DEFRA-Approved if you wish to burn wood in a smoke control area.

ALL OF THE STOVES WE SELL ARE DEFRA APPROVED FOR SMOKE CONTROL AREAS.

In simple terms if a stove has an efficiency rating of 70% then 30% of the heat from your logs goes up the chimney.

If a stove has an efficiency rating of 90% then only 10% goes up the chimney.

So think of this in terms of how many logs you have to chop/buy.

Example: A Saltfire Peanut 5 by Saltfire Stoves in Dorset has an efficiciency of 80%.

A tall chimney (6m or more) that is lined will be happy with an efficient stove.

Efficiency importance can be said to be overrated and anything between 75% and 85% is fine. Go much higher and performance can actually suffer (smoke in room when opening door to reload, blackening of glass).

Many modern stoves can go on 12mm thick hearths. Others require full, 5″ thick constructional hearths. All of the stoves we sell state whether or not a 12mm hearth is suitable.More about hearths for wood stoves here.

Can you can talk to somebody on the phone should you need to after the wood burning stove has been delivered, especially if you are self installing? Will the staff at “wesellzillionsofstoves.com” be able to assist with any installation issues? What if there are any problems after install?

Do yourself a favour before ordering stoves or materials on the Internet: Go to Trustpilot and type in the company name before you buy. Some companies advertising at the top of search engines are not good news - check for yourself.

When striving to find thebest 5kW wood burning stovesyou will likely be bewildered by the choice. There are many to choose from. The question I get asked most in our shop is “why should I pay <£1,000> for this one when this other one is just <£500>?”. Here is the very simple answer:the cheaper wood stoves are made in Chinaor Eastern Europe whilst the more expensive are made in Western Europe (or sometimes the USA). Here are a few examples where a more expensive stove might excel over a cheaper stove:

  • Aesthetics (more time spent on design)
  • Hinges (sometimes hidden on more expensive stoves)
  • Better quality glass
  • Thicker steel (longer life)
  • Improved door locking mechanisms
  • Longer warranty
  • Improved controllabilty of flame due to more resource invested on design of air flow within stove
  • Brushed steel fittings instead of cheapy chrome look

Open and close the door on a cheap Chinese stove. Then open and close the door on a DG stoveArada stovesWoodford stovesHamlet stoves or Saltfire stoves. You’ll understand the difference.

Stove pricing reminds me of wine pricing. A £20 bottle of wine is not double the quality of a £10 bottle of wine (the drinking experience might be improved by 20% as an example). We are talking “the law of diminishing returns here. They are all “fire in a metal box” at the end of the day.

Yes. However, there are specific regulations and restrictions in place to address air pollution concerns, particularly in areas designated as Smoke Control Areas. In these areas, only approved "smokeless" fuels or exempt appliances, such as Defra-approved wood-burning stoves, can be used. These stoves are designed to burn wood more efficiently and produce fewer emissions.

All the stoves we sell are DEFRA approved and Eco-design approved and suitable for all areas of the UK.

Terminology

View all Terminology

A stainless steel tube, slides down a brick/stone chimney to provide a smooth and safe route for smoke.

All of our stoves are approved by DEFRA to burn wood in all UK locations including Smoke Control Areas (towns and cities). Not all stoves are, so be careful if buying elsewhere.

All of our stoves are ECODESIGN approved to be sold in the UK. Not all stoves are, so be careful if buying elsewhere. ECODESIGN is mandatory by law since January 2022.

The base your stove sits on.

If the chimney is the polo mint then the flue is the hole.