Product Overview

G115WS Series
Approval numbers are subject to periodic changes and
updates. Please visit www.buderus.us for the most
up-to-date approval numbers.
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
87% 87% 87% 87%
87%
87%
Piping Connections
Vent Connection Size 5" 5" 5"
Supply 1¼" 1¼" 1¼"
Return 1" 1" 1"
Physical Dimensions
Number 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
Recommended Clearances for Ease of Serviceability
Side 15" 15" 15"
Rear 20" 20" 20"
Front Side Rear Top
Galvanized
Vent Pipe
Flex Insulated
Oil Vent
AT-4 Exhaust
Only Termination
FT-4 Concentric
Termination
24" 6" 18" 6" 18" 1" 1" 1"
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 versatile applications.
The G115WS comes with B-Kit with
Tridicator and Pressure Relief Valve.
The burner kits are available with oil
burner control, flexible oil liner, circulator
and flanges.
23
5
/
8
"
30
3
/
8
"
1
3
/
4
"
10
3
/
8
"
25
1
/
4
"
3
1
/
4
"
2
7
/
8
"
Return
1" NPT
3
/
4
" Drain
Supply
1
1
/
4
" NPT
L
L
K
T
4
5
/
8
"
FRONT VIEW SIDE VIEW REAR VIEW TOP VIEW
Min.
20"
Min.
15"
A Tradition of Excellence
The world leader in heating technologies
since 1825, Buderus produced the
first low-temperature hydronic heating
systems. Today, Buderus products are
acknowledged as the global standard in
high-efficiency, low emissions hydronic
heating. All Buderus products are
designed to meet strict safety and
environmental regulations.
Buderus boilers are quick and easy to
install and will outlast and outperform
virtually any other hot water heating
system. They are designed for easy
access and service. With appropriate
maintenance, Buderus boilers deliver
the highest efficiencies throughout
the lifespan of operation. Buderus is a
member of Bosch Thermotechnology.
75S995023 a 10/14 Copyright © 2014 Bosch Thermotechnology Corp. All rights reserved. Subject to change without notice.
G115WS Direct Vent Installation Tips
ETL approved with two 4" 90˚ elbows, and up to 6' of 4" regular flue 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
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 burners. Please refer to the Buderus trade price list for models.
Bosch Thermotechnology Corp., 50 Wentworth Avenue, Londonderry, NH 03053 • Tel: [phone] • Fax: [phone] • www.buderus.us