Know Your Flue

Listed below you will find a list flue icons to help you identify your current flue.  If your property has a flue, chimney or none at all it is still possible to purchase a fire to suit.

At Fire Design Studio we strongly recommend that you have your property surveyed by one of our qualified gas safe registered engineers before you purchase a new appliance.  Our engineers can identify your current flue type and compatibility and then advise you on what is required before your next purchase.  This will help avoid any disappointment and additional expense that Fire Design Studio cannot accept any liability for on your behalf.

Brick Chimney (class 1 flue application)


Brick chimneys are suitable for all types of fires.  The classic brick-built chimney can handle fires with a deep bed or shallower slimline styles & solid fuel fires.  This is easily recognised by a chimney stack on the roof with a minimum flue diameter of 7".

Prefabricated Flue (class 1 & 2 flue applications)

Pre-fabricated flues are deep enough to accommodate most deep models and all slimline style fires.  The flue is made of metal and has an interlocking flue pipe which can be single or twin wall connected to a flue box with a gas terminal placed on top of the roof.

Pre-cast Flue

Pre-cast flues are suitable for a wide range of slimline fires. Deeper fires can be adapted for pre-cast flues by using a spacer kit.  The flue system is manufactured into rectangular hollow concrete/clay blocks that are placed vertically through the cavity wall to a ridge vent or metal flue terminal on top of the roof. 

No Chimney (Flueless)

Power flue (No chimney application)

If your property has no chimney or no flue system this doesn't mean you can't have a fire. If your fire & fireplace is going to be sited on an outside wall then a power flue gas fire is possible. The power flue gas fire is open fronted (no glass) and has a fan unit on the outside which electronically extracts the flue gases to the outside. The fan can be either semi-recessed into the cavity wall or wall mounted. With this type of fire you are expected to to have a background sound when the fire is on.

Balanced Flue (No chimney application)

All Balanced flue fires are glass fronted and are completely sealed from the room into which they are installed. This type of fire vents directly to an outside wall where air is drawn in through the flue from the outside for combustion. This increases its efficiency through an outer pipe whilst the inner pipe system removes the combustion gases safely.
This type of fire is not electronically operated therefore unlike a power-flue no background sound will be evident.  There is a choice of either outset or inset balanced flue fires.


Please read all the above information to identify your flue in order to select the correct application.  Failure to do so could lead to additional costs that Fire Design Studio cannot accept any liability for.  Please call 0800 033 7136 or e-mail our sales team at if you have any concerns or questions.