Pre-installation
5
Greenstar Condensfit II – 6 721 819 755 (2019/12)
Flue joint fixing screws
▶ Whenever possible, two screws should be fitted, at 180° from each
other on the flue connections, however we recognise that some
installation may make it difficult to access the joint sufficiently to fit
two screws. On these occasions we would deem one screw to be
acceptable.
▶ Where only one screw is used, the screw must be in a visible position
for inspection purposes.
▶ Whenever a flue is identified to have only one screw in each joint,
providing the flue is correctly supported and the screw is only being
used for its intended purpose to prevent the joint from separating and
not for mechanical support, then this would be acceptable.
Maximum flue lengths:
▶ Refer to the Installation and maintenance instructions manual for the
appliance for maximum flue lengths.
3.2
Preparation
3.2.1
Flue measuring
NOTICE:
Flue and plume management lengths:
▶ Do not exceed the maximum straight length for a horizontal 60/
100mm flue or a 60mm plume management system (if used) as
stated in the relevant appliance Installation and maintenance
instructions manual.
The maximum flue length can be found in the Installation and
maintenance instructions manual for the appliance.
The horizontal fixed flue length can be reduced for an effective length [L]
of less than 860mm if required.
▶ Measure the flue length [L] from the centre line of the flue outlet or
flue elbow (if fitted), along the route of the flue system, to the face of
the outside wall.
▶ For flues longer than the standard (860mm) refer to section 3.2.2.
Fig. 5
Flue length determination
[L]
Effective length of the flue system
[R]
Actual length of the flue system (L - 50mm = R)
Effective length
▶ Each flue elbow is rated as a certain straight length of flue, refer to the
relevant appliance Installation instructions. The “effective length” of
each elbow is added to the straight length of flue. Adding elbows to
the flue system reduces the actual flue length available.
▶ The effective length of the flue must not exceed that stated in the
relevant appliance Installation and maintenance instructions manual.
90° Elbow offset dimensions
Figure 6 shows the offset between 2 x 90 ° elbows.
Fig. 6
90° elbows offset
[1]
299mm
[2]
185mm
[3]
190mm
Figure 7 shows the actual length added by a 90 ° elbow when used with
an extension in either orientation.
Fig. 7
90° elbow with extension offset dimensions
[E]
Extension flue length
[1]
112mm
[2]
73mm
Minimum extension length between elbows
The minimum extension length between two elbows/offsets is 130mm,
this allows for a good seal at the connection joints.
50mm
L
R
0010031784-001
0010013695-002
1
2
3
0010013481-002
1
2
