Product Overview

A Tradition of Excellence
The World’s leader in heating
technologies since 1825, Buderus
produced the world’s first low-
temperature hydronic heating
systems. Today, Buderus products are
acknowledged as the world standard
in high-efficiency, low emissions
hydronic heating. All Buderus products
are designed to meet strict safety and
environmental regulations.
With appropriate maintenance,
Buderus boilers deliver the highest
possible efficiencies throughout the
lifespan of operation.
In 2008 Buderus became a member
of the Bosch Group, representing
the Bosch, Buderus and FHP brands
with products that are designed to
improve efficiency, reliability and
are environmentally friendly. Bosch
Thermotechnology offers floor-standing
and wall hung boilers, water heaters,
solar systems, heat pumps, control
systems and tankless water heaters.
G115WS Direct Vent
Installation Tips
ETL approved with two 4” 90˚ elbows, and up to 6’ of 4”
regular smoke pipe for short vent runs. For longer runs,
use up to 10’ of flexible stainless steel insulated oil vent.
Use 4” metal pipe for air intake. Use at least 6’ to 8’ of
4” metal pipe for air intake in conditioned space in cold
climates (below -20˚F). Direct vent burners are equipped
with pre-and post-purge cysles for safe, complete exhaust
of all combustion products, while cooling oil burner nozzle
for positive shut-off. Buderus recommends the use of
Becket, Carlin and Riello burners. Please refer to the
Buderus trade price list for models.
All G115WS models include the
Becket AquaSmart, flexible oil line,
ciculator and flanges.
Bosch Thermotechnology Corp. 50 Wentworth Avenue, Londonderry, NH 03053 Tel: [phone] Fax: [phone] www.buderus.us
44499103 04/11 © 2010 Bosch Thermotechnology Corp. Subject to change without notice.
G115WS
Cast Iron Residential Oil Boiler
Model G115WS/3 G115WS/4 G115WS/5
Performance Data Chimney
Vent
Direct
Vent
Chimney
Vent
Direct
Vent
Chimney
Vent
Direct
Vent
Gross Output BTU/Hr 85,000 74,000 109,000 98,000 136,000 120,000
Net IBR BTU/Hr 74,000 64,000 95,000 85,000 119,000 104,000
Firing Rate (GPH) 0.70 0.60 0.90 0.80 1.10 1. 0
AFUE 86.7% 86.5% 86.9% 86.8% 87% 86%
Piping Connections
Vent Connection Size 5" 5" 5"
Supply 1¼" 1¼" 1¼"
Return 1" 1" 1"
Physical Dimensions
# of Sections 3 4 5
Overall Boiler Length (L) 23
5
/
8
" 28
5
/
8
" 33
3
/
8
"
Boiler Block Length (LK) 21
1
/
8
" 25¾"
30½"
Minimum Boiler Width 18" 18" 18"
Boiler Width 23½" 23½" 23½"
Minimum Boiler Height 33½" 33½" 33½"
Height 34½" 34½" 34½"
Boiler Feet Spacing 10
3
/
8
" 16
1
/
8
" 20
7
/
8
"
Fire Box Depth (T) 16" 20½" 25¼"
Fire Box Volume (cu. ft.) 1.20 1.75 2.21
Dry Weight (lbs.) 330 403 476
Water Content (gal.) 8.7 10.8 12.9
Recommendended Clearances for Ease of Serviceability
Side 15" 15" 15"
Rear 20" 20" 20"
Approvals and Certifications
CRN No# 1495.9C
For CSA approval in Canada
you must order a WMO-1
blocked vent switch.
Front View
4
5
/
8
"
23
5
/
8
"
1
3
/
4
"
30
3
/
8
"
10
3
/
8
"
25
1
/
4
"
Supply
1
1
/
4
" NPT
Min. 20"
Min.
15"
Return
1" NPT
3
/
4
"
Drain
25
1
/
4
"
3
1
/
4
"
2
7
/
8
"
L
K
T
Side View Rear View Top View
Front Side Rear Top
Galvanized
Vent
Pipe
Flex
Insulated
Oil Vent
AT-4
Exhauust Only
Termination
FT-4
Concentric
Termination
24" 6" 18" 6" 18" 1" 1" 1"
G115WS direct vent installation tips
ETL approved with two 4" 90° elbows, and up to 6' of 4" regular smoke pipe for short vent
runs. For longer runs, use up to 10' of flexible stainless steel insulated oil vent.
Use 4" metal pipe for air intake. Use at least 6' to 8' of 4" metal pipe for air intake in
conditioned space in cold climates (below –20º F)
Direct vent burners are equipped with pre-and post-purge cycles for safe, complete exhaust
of all combustion products, while cooling oil burner nozzle for positive shut-off.
Buderus recommends the use of Becket, Carlin and Riello. Please refer to the Buderus trade
price list for models.
AT-4 Aerocowl Termination
6
4
4
4
26"
9"
5"
3"
7
13"
18"
FT-4 Concentric Pipe-in-Pipe Termination
One of the two ETL certified terminations are required for use with G115WS series boilers
for direct vent applications. Both terminations are “zero clearance” systems for easy and
versatile applications.