Ferlux C17 A.EXT Use And Maintenance page 13

The cross-section must be the same throughout. There must be no more than two changes in direction and their angle must not be greater than 45º from vertical for
chimneys up to 5 m or 20º for those of greater height.
In the case of a tall flue (over 1.8 m), it is advisable to locate a clean-out door in the chimney to facilitate soot-removal using a vacuum cleaner.
The draught created by the flue must be adequate but limited.
The draw-down at the bottom of the flue should be 5-10 Pascals, which almost always means that a suitable damper will need to be installed.
The damper must always be visible and accessible from the room in which the fireplace is located and must be self-closing when the draught pressure drops.
Check the condition of the existing flue carefully, as many are too old or inappropriate, an unusual build-up of dirt could present a hazard or, the most
frequent case, they may not be suitable or designed to withstand the smoke temperatures of around +500ºC that have been measured in fireplaces with a lively
fire.
An over-sized flue can be too large to heat up and can therefore cause fireplace performance problems. To avoid these, we recommend re-lining the entire flue in
these cases.
CHIMNEY CONNECTION
The flue must provide every assurance of absolute safety and resistance:
- Proof against the effects of the combustion product temperatures
- Perfect air/smoke-tightness
- Adequate flue cross-section
The stainless steel pipe must overlap the collar by a minimum of 40 mm and the joint must be sealed with refractory mortar to ensure air/smoke tightness.
CHIMNEY CONNECTORS AND RE-LINERS
The following materials are forbidden for chimney connectors and pipes: aluminium, aluminised steel and galvanised steel.
The use of rigid or flexible multi-fuel pipes must be justified by a technical report approving such use.
Additionally, in the case of a re-lining pipe, it is obligatory to vent the air between the interior of the masonry flue and the outer surfaces of the liner, a 15 x 10 cm
space for example, at top and bottom in the attic or where the chimney passes through the ceiling.
EXAMPLES OF INSTALLATION
Example with incombustible wall, floor and ceiling
VENTILATION
WARNING! VERY IMPORTANT
It is dangerous to overheat the appliance
Never light the fire when the room contains combustible gases.
Smoke may emerge from the appliance on lighting the fire if, for example, the ventilation system causes draw-down in the room where it is located. This generally
occurs in rooms equipped with CMV (Conventional Mechanical Ventilation) air extraction systems (cooker hoods, etc.)
FIREPLACES
INSERTS
Example with combustible or thin wall, floor and ceiling
The insert must not be connected to an exterior air
intake to provide combustion air, only connection with an
air inlet for the air to be heated is advised.
ENG
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