GB125 Concentric Vent - Buderus

Applications manual
GB125 Concentric Vent
Design Manual
9.1. Installation in an existing chimney shaft
Before starting any installation work, ensure that all
included items are present, plus any additional pieces
needed to complete the job.
The chimney must be thoroughly cleaned before
installing the flue gas system. It is recommended
to use a professional chimney sweep.
If the chimney cannot be sufficiently cleaned, and
dust generation is anticipated or residue of oil or
solid fuel fired appliances remains, the DO or
HTK systems should be used instead.
Fig. 10 load bearing elbow installation
1 Support rail
2 Load bearing elbow
A stainless steel chimney termination is available for
installations with multi-flue chimneys and a risk of ambers
from wood stoves or similar appliances reaching the top
of the chimney. For details see page 24.
If the chimney is not a straight run, verify that the bend is
accessible for the installation of elbows. If it is
inaccessible, use the UB Flex liner instead of rigid pipe.
Determine the position of the chimney penetration in the
boiler room. Position the hole into the chimney such that
the vent pipe to the boiler adapter runs at a 5/8” pitch per
foot (55mm per meter) to allow condensate to drain into
the boiler reliably. The size of the opening must be
sufficient to install the support rail as shown in Fig. 10.
Drill a 3/8” (10 mm) hole in the rear wall of the chimney at
1-3/8” (35 mm) above the bottom of the chimney
penetration (Fig. 10). Shorten support rail (Fig. 10, Item
1) if necessary and insert the rod into the hole. Lay the
near end onto the bottom of the penetration and ensure it
is level and rigid. After the chimney pipes have been
installed and connections made, it will be mortared in
place.
Place load bearing elbow (Fig. 10, Item 2) in the middle
of the support rail (Item 1) with its guide engaging with
the rail.
Use a rope to determine the exact length between the
gasket of the load bearing elbow and the top of the
chimney.
Proceed to page 18 if you are using rigid pipe, or page 21
for flexible liner UB flex.
GB125 Concentric Vent Design Manual | 05.2009
Technical specifications are subject to change without prior notice
| 17