Flavel Ora Installation And Maintenance Instructions Manual page 6

There must be no leakage of smoke through the structure of
the chimney during or after the smoke pellet test and it is
important to check inside upstairs rooms adjacent to the chimney /
flue. Check the chimney pot / terminal and general condition of the
brickwork or masonry. If the chimney or flue is in poor condition or if
there is no up-draught do not proceed with the installation. If there is a
history of down-draught conditions with the chimney / flue, a tested and
certificated flue terminal or cowl suitable for the relevant flue type should
be considered.
6. A spillage test must always be carried out during commissioning of
the appliance.
1.6 FIRE PLACE OPENING AND CHIMNEY CATCHMENT SPACE
The front opening of the fire place must be between 330 and 430 mm wide, and
between 550 and 565mm high. If the opening exceeds these dimensions then a
surround must be constructed from suitable non-combustible material to produce a
correct size opening. Any surround must be suitably sealed to the fire place to
prevent leakage. See below in fig.1
Fig. 1
550mm Minimum
565mm Maximum
When installing into a brick built chimney, you must ensure that there is sufficient
depth to accomodate any debris which may fall from the chimney. This depth
must be sufficient to accomodate 12 litres of volumetric space.
520mm Minimum
Fire Opening
330mm Minimum
430mm Maximum
6
Minimum Flat
Sealing Area
610mm
Minimum