Quick Guide to Buying a Fire and Chimney and Flue Types

Fireplace.co.uk buying a fire and chimney and flue types


Flue  & Chimney Type


Fire options


 blog- gude to flues and fires-class 1

Class 1

Conventianal brick chimney

Solid fuel fires and stoves, gas,  electric or gel fires 

Internal Diameter 7 inches or more

 blog-guide flue and fires-class 1 and 2

Class 1& 2 Flue


Constructed of interlocking single or twin walled metal flue pipe connected to a flue box.

Gas,  electric or gel fires

7 inch diameter  class 1 flue,  5 inch I diameter  class 2 flue

 blog-gide fire and flue-pre cast

Pre Cast Flues

Constructed from clay or concrete blocks installed in the cavity wall of modern builds.


Gas, electric or gel fires

Pre-cast flues are often narrow limiting depth of suitable fires although deeper fires can be installed using spacers or by deepening the rebates on the fireplace

 blog - guide to flues and fires-balanced

Balanced Flue

The flue is a tube within a tube. The outer tube draws combustion air into the fire whilst the inner tube expels combustion gases away from the property. Fire must be situated on an outside wall.


Suitable for glass fronted gas appliances, electric or gel fires.

Fire must be situated on an outside wall.


blog-giuide to flue and fire types-power flue 

Power Flue

Equipped with a concealed electronically controlled fan system to expel combustion gasses through the wall.


Suitable for open fronted gas fires, electric or gel fires.

Fire must be situated on an outside wall and deeper fires can be installed using spacers or by deepening the rebate on the fireplace. An electrical supply needs to be close at hand.   

 Gblog-guide to flue and fires-fluless


Fluless gas appliances   incorporate the latest in gas fire technology using a catalytic converter, which the combustion gases pass through converting all harmful gases into carbon dioxide and water vapour. 

Fluless gas, electric of which there are now some very life like effect fires available and the growing market of bio ethanol fires.  


Fluless gas fires require minimum room sizes 16 to 20 m3 and ventilation requirement 100cm3and are not designed as a property’s primary heat source

For further information regarding chimneys please visit fireplace.co.uk ’s  Knowledge Hub Chimney theme and forn help in choosing a fire see theme how to choose a fire, stove, hearth and fire surround. For further useful and informative articles please visit the Knowledge Hub by clicking the log below or via fireplace.co.uk 's home page   


by Phil Cleaver


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