If you’re looking into the possibility of buying and installing a log burner or gas stove in your home then it is worth making sure you have all the right parts for the job. Once you’re set on the style and heat output of your chosen stove the next integral piece of your installation is the flue liner. A flue liner can be fundamental to modern installations, they ensure your heating appliance works efficiently and safely. In this edit, we’ll explain the purpose of a flue liner and the various benefits of installing one within your chimney.

Contents

What is a chimney flue liner
Which size flue liner do I need?
The benefits of a flue liner for your stove
Should I install a flue liner with my log burner?
Chimney sweeping & maintenance advice

Simply put, a flexible flue liner is a stainless steel tube that hangs down from your chimney pot or stack and connects into the stove pipe that slots into the flue collar of your log burner or gas stove. A flue liner, which is often referred to as a chimney liner or steel flue, sits on the inside of your brick built chimney and carries the exhaust gases away from your stove and up your flue liner instead of releasing them directly into your chimney cavity.

There are two different grades of solid fuel flue liner available: 316-grade flue liner and 904-grade flue liner. We recommend 316-grade chimney liners for dedicated wood burning stoves that will burning seasoned or kiln dried firewood. This type of flue liner is cheaper than the more expensive but also more durable 904-grade flexible flue liner. You should upgrade to 904 flue liner if you plan on burning smokeless coal frequently. Both these good quality flue liners that we supply are Hetas approved and should last up to 25 years if maintained correctly and you use the right type of fuel.

It is crucial that you use the recommended flue liner size for your specific stove or fire and never reduce the diameter of the flue. When buying a log burner or gas stove you’ll need to find out the diameter of the flue collar of the stove and this is often a good guide to gauge the correct size of liner you’ll required for the stove. The size of the stove collar however does not always correspond to the size of the flue liner you’ll need so ensure you check the manufacturer's instructions before you purchase a flue liner.

The general rule for getting a suitably sized flue liner is that for up to 20kW stoves a minimum of 6” diameter flue liner is required. You can use a 5” diameter flue liner if you have a DEFRA-approved stove and the manufacturer has confirmed this is compatible with this size flue. If the flue collar of the stove measures 5” in diameter but you need a 6” flue liner there are adapters available that allow for the increase in diameter. When measuring the length of your flue liner our main piece of advice is a simple one, you must ensure it is long enough to reach from the top of your chimney to the bottom of the fireplace opening. Connecting two pieces of flue liner together is against regulations so double checking the length you need is essential. We recommend ordering an extra metre or two of flue liner to cater for any bends or offsets that you may have within your chimney space.