9
Part Number 550-142-785/0812
Table 4 Maximum vent length
Max.vent length
(feet)
Total number of 90° elbows
(Notes 1 & 2)
1
2
3
4
5
6
GWI-047 to GWI-158
55
48
41
34
27
20
GWI-190
35
28
21
14
7
--
Notes:
1. Do not include termination fitting when counting total number of elbows.
2. One (1) 90° elbow is equivalent to two (2) 45° elbows.
GWI
Series 2
Gas-Fired Water Boilers –
Boiler Manual
Direct exhaust venting
Obtain vent system components
1. The following special gas vent systems comply with UL-1738
and ULC-S636 standards and are certified by CSA as the only
systems suitable for use with GWI boilers (all 3” diameter):
• Heat-Fab, Inc. Saf-T Vent
®
• Flex-L International, Inc. StaR-34
• Z-Flex
®
, Inc. Z-Vent II
• ProTech Systems FasNSeal™
Use only the vent starter of the same manufacturer
as the vent components. Do not mix components
from different systems. The vent system could fail,
causing flue gas spillage, resulting in severe per-
sonal injury or death.
2. Select vertical or sidewall venting depending on job require
-
ments.
3. Refer to Table 4 for maximum vent run lengths and number of
elbows. Do not exceed data in
Table 4.
4. Select vent components from separate
GWI Vent Component
Supplement
. All components, including the vent starter, must
be of the same vent manufacturer. Do not mix components.
1. Select a vent pipe manufacturer from separate
GWI Vent
Component Supplement and obtain all vent components
needed, based on boiler location and venting method.
2. You must use the vent starter (see below) made by the vent pipe
manufacturer. See
GWI Vent Component Supplement
for
part number of each component, listed by vent manufacturer.
Use only the vent starter of the same manufacturer
as the vent components. Do not mix components
from different systems. The vent system could fail,
causing flue gas spillage, resulting in severe per-
sonal injury or death.
3. Follow all applicable national, state, local or provincial codes
when venting the GWI boiler.
4. Connect vent starter to blower housing outlet as shown below.
a. Do not mix components from different vent manufacturers.
b. Maintain minimum 2” clearance from combustible materials
to vent pipe.
c. Seal with sealant specified by vent pipe manufacturer,
using
3
/
8
” bead (not required for FasNSeal™).
d. Tighten strap at band clamp screw until strap is snug
around blower housing.
3 Vent installation
continued
