Valor Quantum & Urban 746 Installer's Manual page 8

INSTALLER GUIDE
The current revision of the standard requires 16,500mm 2 . This appliance is suitable in
both cases. The total depth of the opening measured from the finished front of the
fireplace (Including plaster, surround etc.) must be not less than 120mm. See figure 3.
The current versions of BS1289 and BS EN 1806 recommend 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.
3.2.4 If the fireplace opening is greater
than the acceptable dimensions given in
this guide, do not use the back of a fire
surround or marble to reduce the
opening. This may cause cracking of the
surround back or marble.
3.3 The following flues are suitable:
225mm x 225mm conventional brick
flue.
If a flue liner is used, it must be a
minimum of 125mm diameter. The liner
must be sealed to the surrounding area
above the fireplace opening and to the
Figure 3. Pre-cast Fireplace
top of the chimney. An approved terminal
must be fitted.
A properly constructed precast flue conforming to B.S 1289 or BS EN 1806.
A flue pipe with a minimum diameter of 127mm. See B.S 6461 Part 1 for suitable
materials. Metal flue pipes must comply with B.S 715.
3.3.1 The minimum effective height of the flue must be 3m.
3.3.2 The flue must be clear of any obstruction and its base must be clear of debris.
3.3.3 The flue must be completely sealed so that combustion products do not come into
contact with combustible materials outside the chimney.
3.3.4 The flue must serve only one fireplace.
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