Osburn 900 Installation and Operation Manual
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The rules below are based on those found in the AS/NZS 2918:2001 installation code. Please
carefully follow these installation instruction rules, or those enforced where you live.
•
Maximum overall length of straight flue system: not less than 4.6 m above the top of the floor
protector.
•
The flue should be as short and direct as possible between the wood fire and flue system. The
use of two 45° elbows is often preferable to a single 90° elbow because less turbulence is
created in the exhaust flow and they result in less horizontal run.
•
Flue must be at least 24 gauge in thickness.
•
Flue joints should overlap 30 mm.
•
Each joint in the flue must be fastened with at least three screws.
•
The flue must have allowance for expansion: elbows in assemblies allow for expansion; straight
assemblies should include an inspection wrap with one end unfastened, or a telescopic
section.
•
There must be provision for cleaning of the flue, either through a clean out or by removal of
the flue. Removal of the flue should not require that the wood fire be moved.
•
The male ends of the sections must be oriented towards the appliance so that falling dust and
condensation stay inside the wood fire.
•
A flue must never pass through a combustible floor or ceiling or through an attic, roof space,
closet or concealed space.
•
Where passage through a wall or partition of combustible construction is desired, the
installation shall conform to AS/NZS 2918:2001.
The ideal flue is one that rises straight up from the appliance flue collar and directly into the flue
system with no elbows. A straight up flue needs either a telescopic length or an inspection wrap
(flue coupler) to allow it to be assembled and disassembled without moving the wood fire.
A straight flue offers the least restriction to gas flow and results in stronger draft. Straight
assemblies also need less maintenance because there are no corners to collect creosote.
The flue must be in good condition.
