4 Flue and Chimneys
The stove must be connected to a suitable and efficient flue so that products
of combustion (fumes) from the stove are expelled to the outside air. Please
remember that chimney draught is dependent on four main factors :
Flue gas temperature
Flue height
Flue size
Flue terminal
To ensure a good up draught it is important that the flue gases are kept
warm and that the flue size suits the stove. The termination of the outlet at
the top of the flue also needs to comply with Building Regulations.
The minimum effective height of the flue must be at least 4.5 metres from the
top of the stove to the top of the flue outlet. When warm the flue draught
should be between 0.1 to 0.2 mbar.
The draw of a chimney / flue can vary in different weather conditions and the
customer should be made aware of this.
Failure to correct an over-drawing flue will invalidate the warranty.
A chimney may comply with regulations but could still be subject to down
draught and similar problems. A chimney terminating above the ridge level is
generally less likely to suffer such problems.
If a new chimney is being provided it should fully comply with the relevant
Building Regulations that specify the requirements for solid fuel burning
installations. Suitable types of chimney include the following :
Masonry Chimney : Built with clay or concrete liners, or a
chimney block system meeting Building Regulations. These
types of chimneys should be installed in accordance with
the Building Regulations and BS EN 15287-1:2007.
Factory Made Insulated Chimney : Complying with BS
4543:Part 2 (often called Class 1 prefabricated metal
chimney). These types of chimneys should be installed
in accordance with Building Regulations and BS EN
15287-1:2007.
Page 9
BK 680 Specific
ECOBOILER Cassette Installation Guide