Valor BR622 Installer's Manual page 6

be no less than the distance shown in
figure 3. The distance from the front face
of the flueway opening in the lintel block
(or equivalent) to the extreme front face of
the fireplace including all surfacings must
be no more than the distance shown in
figure 3. If this maximum is exceeded
poor clearance of combustion products
could result.
The flue starter blocks should not be
modified.
The current version of BS1289
recommends that there should be an air
space or insulation between the flue
blocks and the plaster because heat
transfer may cause cracking on directly
plastered flues. However, generally this
appliance is suitable for installations under
all circumstances unless there is a history
of cracking problems.
Remember that faults such as cracking
may be caused by poorly built and
restrictive flues, e.g. mortar extrusions,
too many bends, flue heights below three
metres, restrictive terminations etc.
2.3.2 Into a fireplace that has a fireback of
nominal size 400mm or 450mm and
conforming to BS1251. The distance from
the front face of the flueway opening in
the lintel (or equivalent) to the extreme
front face of the fireplace including all
surfacings must be no more than the
distance shown in figure 4. If this
maximum is exceeded poor clearance of
combustion products could result.
2.4 Suitable flues and minimum flue sizes are
as follows:-
a) 225mm x 225mm conventional brick flue.
b) 175mm diameter lined brick or stone flue.
c) 200mm diameter factory made insulated
flue manufactured to BS4543.
d) 175mm diameter flue pipe. See BS6461
Part 1 for suitable materials.
e) Single wall, twin wall or flexible flue liner
with a minimum diameter of 125mm. The
materials to be used are stainless steel or
INSTALLER GUIDE
2.5
2.6
2.7
2.8
2.9
2.10 The appliance must be mounted behind a
Page 6
aluminium as specified in BS715.
f) A properly constructed precast concrete or
clay flue system conforming to BS1289 Part 1
or 2. This system is only suitable when the
conditions stated in section 2.3 are met.
It should be noted that, as with many
appliances, sharp bends or horizontal runs
in metal flues at the top of the system
can be a cause of problems in these types
of installation.
The minimum effective height of the flue
must be 3m.
The flue must not be used for any other
appliance or application.
Any chimney damper or restrictor should
be removed. If removal is not possible,
they must be secured in the open
position.
If the appliance is intended to be installed
to a chimney which was previously used
for solid fuel, the flue must be
swept clean prior to installation. All flues
should be inspected for soundness and
freedom from blockages.
If the fireplace opening is an underfloor
draught type, it must be sealed to stop
any draughts.
non-combustible hearth (N.B.
conglomerate marble hearths are
considered as non-combustible). The
appliance can be fitted to a purpose made
proprietary class "O"-150
The hearth material must be at least
12mm thick. The periphery of the hearth
(or fender) should be at least 50mm
above floor level to discourage the placing
of carpets or rugs over it.
The surface of the hearth must be
sufficiently flat to enable the bottom of the
front surround and the bottom front
cover to be aligned horizontally. Any
excessive unevenness (uneven tiles,
Cotswold stone, etc.) should be rectified.
The appliance must not stand on
combustible materials or carpets.
0 C surround.