Viessmann VITODENSd 100-W Instruction manual

Technical Data Manual
VITODENS
d
100-W
5601 189 v1.1 09/2011
Vitodens 100-W
WB1B Series
Wall-Mounted, gas-fired condensing boiler
with optional on demand hot water CombiPLUS Kit
Heating input: 37 to 118 MBH
10.8 to 34.5 kW
Model Nos. and pricing: see Price List
Vitodens 100-W, WB1B
(with pre-installed coaxial vent pipe adaptor) CombiPLUS Kit
Gas-Fired Wall-Mounted Condensing Boiler with modulating
stainless steel MatriX cylinder burner, stainless steel Inox-
Radial heat exchanger for room air independent operation
(using a direct vent system) or room air dependent operation.
Optional CombiPLUS Kit providing reliable on demand hot
water without a DHW tank is available.

2
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Product Information
General
Equipped with a Viessmann stainless steel heat exchanger
for lasting performance and reliability and a modulating
MatriX cylinder gas burner, the Vitodens 100-W wall-
mounted condensing boiler is the perfect combination of
value, quality and Viessmann technology.
The benefits at a glance:
Outstanding efficiency
of 94.0 % A.F.U.E. on all models.
Lasting performance
with Viessmann-made SA240 316Ti stainless steel
Inox-Radial heat exchanger constructed to ASME
Section IV and CSA B51.
Low-emission
with fully-modulating stainless steel MatriX cylinder
burner. Factory calibration eliminates adjustments in
the field.
< 29 ppm NOx (at 3% O2)
< 40 ppm CO (at 3% O2)
Control variety
Integrated boiler control interfaces with any level of
external control - from room thermostat to outdoor
reset and more.
Compact, lightweight wall mount design
and zero clearance to combustibles make it a great
choice for limited-space installations.
Extremely quiet operation
quieter than most refrigerators.
< 50 dBA [at 3.3 ft. (1 meter)]
Easy installation, service and maintenance
with all pipe connections located at the bottom
and serviceable components (including electrical
connections) easily accessible from the front.
Multiple venting options
- Horizontal or vertical sealed combustion
coaxial, PP(s) vent system (Viessmann supplied).
- Horizontal, vertical or hybrid sealed combustion
double-pipe CPVC vent system (field supplied).
- Horizontal or vertical single pipe CPVC vent system
(field supplied).
- Horizontal or vertical single or double pipe PP(s),
flexible vent system (Viessmann supplied).
Suitable for high altitude levels
of up to 10,000 ft. (3,000 m) without deration.
Built-in automatic frost protection
allows boiler to be shut off for an extended period
of time while protecting it against freeze-up.
Reliable on demand hot water
with an optional CombiPLUS kit (no DHW tank required).
- Plate type heat exchanger
- Built-in diverting valve
- Built-in Grundfos 3-speed pump
- Built-in pressure bypass valve
- Built-in water hammer arrester
- Built-in flow sensor
- Built-in temperature sensor
- Supplied with a pressure relief valve rated at 150 psi
Note: Check the boiler rating plate on the Vitodens 100-W,
models WB1B-26 or WB1B-35 to ensure it states
compatibility with the CombiPLUS kit.
Limited lifetime warranty
in residential applications.

3
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data General
Product Information
Boiler cross-section
Legend
AStainless steel MatriX cylinder burner
BInox-Radial stainless steel heat exchanger
CBurner blower
DGas and hydronic connections
EBoiler control
Standard Equipment:
Wall-mount boiler and installation fittings c/w 30 psi
pressure relief valve, pressure gage, gas shut-off valve,
two fill/drain valves, all mounting hardware, outdoor
temperature sensor, and LP conversion kit.
CombiPLUS cross-section
Legend
F Plate-type heat exchanger
GBoiler / DHW pump
H Flow sensor
I Pressure by-pass valve
J Diverting valve
Note: Products may not look exactly as illustrated.
GF
J I H

4
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Specifications
Technical Data
Standard heating boiler
Boiler Model No. WB1B 26 WB1B 35
Natural gas and LPG
CSA input
CSA output/DOE 1
heating capacity
Net I=B=R rating 2
MBH
kW
MBH
kW
MBH
37-91
10.8-26.7
34-83
9.9-24.3
72
37-118
10.8-34.6
34-108
9.9-31.6
94
Heat exchanger surface area
ft.2
m2
10.23
0.95
10.23
0.95
Min. gas supply pressure
Natural gas
LPG
“w.c.
“w.c.
4
10
4
10
Max. gas supply pressure 3
Natural gas and LPG “w.c. 14 14
A.F.U.E. % 94.0 94.0
Weight lbs
kg
78
34.1
78
34.1
Shipping weight lbs
kg
95
43
95
43
Boiler water content USG
L
0.87
3.3
0.87
3.3
Boiler max. flow rate 4 GPM
L/hr.
6.2
1400
6.2
1400
Max. operating pressure
(max. allowable working pressure)
at 210º F (99º C)
psig
bar
45
3
45
3
Boiler water temperature
- Adjustable high limit (AHL) range
- space heating (steady state)
- DHW production (set-point)
- Fixed high limit (FHL)
ºF (ºC)
ºF (ºC)
ºF (ºC)
86 to 176 (30 to 80)
176 (80)
210 (99)
Boiler connections
Boiler heating supply and return
Pressure relief valve
Drain valve
NPTM (male) “
NPTF (female) “
(male thread) “
c“
c“
c“
c“
c“
c“
Dimensions
Overall depth
Overall width
Overall height
inches
mm
inches
mm
inches
mm
14d
360
15 c
400
28 b
725
14d
360
15 c
400
28b
725
1Output based on 140º F (60º C), 120º F (49º C) system supply / return temperature.
2Net I=B=R rating based on piping and pick-up allowance of 1.15.
3If the gas supply pressure exceeds the maximum gas supply pressure value,
a separate gas pressure regulator must be installed upstream of the heating system.
4See “System Flow Rates” on pages 20 to 25 in this manual.

5
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Specifications (continued)
Technical Data
Boiler Model No. WB1B 26 WB1B 35
Gas supply connection NPTF
(female)” c c
Flue gas 5
Temperature at boiler
return temperature of
86º F (30º C)
- at rated full load
- at rated partial load
Temperature at boiler
return temperature of 140º F (60º C)
ºF (ºC)
ºF (ºC)
ºF (ºC)
127 (53)
90 (32)
167 (75)
131 (55)
90 (32)
172 (78)
Flue gas value
Mass flow rate (of flue gas)
- at rated full load
- at rated partial load
Available draught
lbs/h
kg/h
lbs/h
kg/h
Pa
mbar
79.2
36.0
33.0
15.0
100
1.0
100.1
45.5
33.0
15.0
100
1.0
Flue gas temperature
sensor limit ºF (ºC) 230 (110) 230 (110)
Average condensate
flow rate 6
with natural gas
- TS/TR=122 / 86º F (50 / 30º C) USG/day
L/day
1.95-2.3
8-9
2.5-2.8
9.4-10.5
Condensate
connection 7
hose
nozzle
Ø in 1 1
Boiler flue gas
connection 8
Ø
in (mm) 2e(60) 2e(60)
Combustion air supply coaxial
connection 8 single
outer Ø in (mm) 4 (100)
2e(60)
4 (100)
2e(60)
Noise level (at 1 meter)
- at full load
- at partial load
(dB)
(dB)
47
40
49
42
High altitude (factory set) 9ft. (m) 0-5,000 (0-1,500) 0-5,000 (0-1,500)
Standard heating boiler (continued)
5Measured flue gas temperature with a combustion air temperature of 68° F (20° C).
6Based on typical boiler cycles, including partial load conditions.
7Requires 1”(25) mm tubing. See Vitodens 100-W Installation Instructions for details.
8For detailed information refer to the Vitodens Venting System Installation Instructions.
9For 5,000 to 10,000 ft. (1,500 to 3,048 m) operation, a control programming change is required.
Refer to the Installation and Service Instructions for details.
u For information regarding other Viessmann System Technology componentry,
please reference documentation of respective product.

6
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Specifications (continued)
Technical Data
Boiler Model No. WB1B 26 WB1B 35
DHW supply temperature ºF (ºC) 140 (60) 140 (60)
Continuous draw rate 1
with DCW temp. of 56º F (13º C)
USG/h
L/h
99
374
147
556
Continuous draw rate 2
at ∆t= 63º F (35K)
USG/h
L/h
156
589
216
800
Maximum allowable working
pressure (potable water) psi 150 150
Test pressure psi 300 300
Connections, DHW and DCW NPTM (male) “ b“b“
Connections to boiler supply/return
and to heating supply/return
NPTM (male) “ c“c“
Dimensions
Overall depth
Overall width
Overall height
Height with pipe connector
inches
mm
inches
mm
inches
mm
inches
mm
9.8
250
17
432
8.7
223
13
331
9.8
250
17
432
8.7
223
13
331
Integrated pump flow rate
DHW production @ 23 ft. (9.8 m)
Head pressure
Heating system operation
with system side additional
drop in pressure of max. 6 ft. of
water (1.8 m)
USG/min.
L/h
USG/min.
L/h
5.63
1278
6.2
1408
5.63
1278
6.2
1408
Weight lbs
kg
25
11
25
11
CombiPLUS (Integrated with the Boiler)
1Based on boiler max. output and boiler supply temperature of 176º F (80º C).
2DCW and DHW temperature rise would be proportional. Maximum DHW supply temperature is 140º F (60º C).

7
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data Dimensions
Boiler dimensions without bottom piping connections
Connections Vitodens 100-W, WB1B 26, 35
Legend
Connections
ACondensate drain, plastic hose Ø 0.87” (22 mm)
BBoiler water supply, NPT ¾” (male thread)
CGas connection, NPT ¾” (male thread)
DBoiler water return, NPT ¾” (male thread)
ECombustion air opening for double pipe system
FCombustion air opening for coaxial system
Dimensions
a See illustration for dimensions
b 15¾” (400 mm)
c 2f” (68 mm)
d 28½” (725 mm)
e 47/8” (123 mm)
f 6d” (156 mm)
g 14d” (360 mm)
h 5” (125 mm)
j 12” (305 mm)
k 1a” (31 mm)
m 77/8” (200 mm)
n 3d” (80 mm)
Front view Side view Top view
Note: If using the optional CombiPLUS see page 9.

8
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Dimensions
Boiler dimensions with piping connections
Piping connections for Vitodens 100-W,
WB1B 26 and 35 (factory supplied)
Legend
BWR Boiler water return, ¾”
BWS Boiler water supply, ¾”
BD Boiler drain
BF Boiler fill
GC Gas connection, ¾” NPTM (male thread)
PRV Pressure relief valve
PG Pressure gage
VC Venting connection
CAI Combustion air inlet connection (optional)
Note: If using the optional CombiPLUS see page 9.

9
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data Dimensions
CombiPLUS dimensions and piping connections
CombiPLUS Connections
Top view
Side view
Front view
A B
C DE F
Front view
Legend
ABoiler water supply, NPTM ¾” (male thread)
BBoiler water return, NPTM ¾” (male thread)
CSystem water supply, NPTM ¾” (male thread)
DSystem water return, NPTM ¾” (male thread)
EDHW, NPTM ½” (male thread)
FDCW, NPTM ½” (male thread)
with 7”
flex pipes

10
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Boiler minimum clearances
Dimensions
Recommended minimum boiler and CombiPLUS Kit
clearances to combustibles
AL = Alcove
CL = Closet
*1Refer to the Installation Instructions
of the Vitodens Venting System
for details.
Note: The Vitodens 100-W boiler has passed the zero
inches vent clearance to combustibles testing
requirements dictated by the boiler latest
Harmonized Standard ANSI Z21.13. CSA 4.9.2007
and therefore is listed for zero clearance to
combustibles when vented with a single-wall special
venting system (AL-29-4C material) or UL/ULC-listed
CPVC/PP(s) gas vent material. The zero inches vent
clearance to combustibles for the Vitodens 100-W
boiler supercedes the clearance to combustibles
listing that appears on the special venting system
label.
CombiPLUS installation options
Min. distance between the boiler and CombiPLUS with
Viessmann supplied 7” flex piping connection fittings.
Shown is the maximum distance between the boiler
and CombiPLUS using field supplied fittings and pipes.
Note: The maximum distance between
the boiler and the CombiPLUS
is restricted by the
communication
cable to 36” (915 mm).
Recommended minimum boiler service clearances
Front
Side
Side
Back
Top
7”/178mm
5
Top Front Rear Left Right Vent
pipe*1
0 0 AL,
CL
00 0 0

11
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data Operation
Heating circuit pumps
Waterside Flow (boiler circuit)
The Vitodens 100-W is designed only for closed loop,
forced circulation hot water heating systems.
Pressure drop (primary circuit) of Vitodens 100-W
Heating circuit pumps (field supplied)
Recommended heating pumps with Vitodens 100-W,
WB1B 26, 35 (without an optional CombiPLUS).
gGrundfos 15-58 (3-speed)
gTaco 00R
or equivalent
Refer to the graph for the proper waterside boiler friction
loss calculations.
Pump selection must be based on accurate system flow
and pressure drop calculations (including DHW sizing).
A low-loss header must be used when the system flow
rate exceeds the maximum (or minimum) flow rate of
the Vitodens 100-W boiler. An alternative method may
be used, such as primary secondary piping using closely
spaced tees.
A low-loss header offers additional
benefits not provided by a pair of closely spaced tees.
Viessmann strongly recommends and prefers the use
of a low-loss header over closely spaced tees.
Please see page 18 for details.
Use standard friction loss method for pipe sizing.
Observe boiler maximum and minimum flow rate limitations.
If system flow rate exceeds boiler maximum flow rate
(as stated on page 18) or if system flow rate is unknown,
Viessmann strongly recommends the installation of
a low-loss header. See page 18 for low-loss header
information or refer to the Vitodens Venting System
Installation Instructions.
IMPORTANT
ft. m
Pressure Drop
Flow rate
USGPM
L/h

12
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Heating circuit pumps (continued)
Operation
Pump Model Grundfos UPS15-78
Rated voltage VAC 115
Rated current A max. 1.15
A min. 0.8
Capacitor lF8
Power consumption W max. 130
W min. 80
CombiPLUS built-in pump
Grundfos UPS15-78 three speed heating circuit/DHW production pump for Vitodens 100 WB1B 26, 35 boilers
(in the factory setting, the pump speed is preset to ‘speed three’)
Speed One
Speed Three
Speed Two
Flow Q (gpm)
Head H (ft of wc)
Performance chart courtesy of Grundfos
CombiPLUS built-in pump, Grundfos UPS15-78 residual head pressure
Residual head of built-in three speed pump used with Vitodens 100 WB1B 26, 35
Flow Q (gpm)
Head H (ft of wc)

13
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data Operation
Heating circuit pumps (continued)
DHW Production Planning
With the CombiPLUS for instantaneous DHW heating
or with DHW connections for DHW production via a
stand-alone DHW storage tank, the Vitodens 100 boiler
series offers the right solution for every need.
Various factors must be taken into account when
designing the DHW system, and when deciding between
the DHW production with integrated CombiPLUS and the
standard heating boiler with DHW production via a stand-
alone DHW storage tank.
Options
Gas-fired boiler
with instantaneous
CombiPLUS
production
Gas-fired standard
heating boiler
with stand-alone
DHW storage tank
DHW requirement,
level of comfort and
convenience
DHW requirement for an apartment + +
DHW requirement for a single-family house 0 +
Central DHW requirement for a multi-family house - +
Decentralized DHW requirement for a multi-family house + +
Number of draw points One draw point + 0
Several draw points, non-simultaneous use + 0
Several draw points, simultaneous use - +
Distance of draw
points from the boiler/
DHW storage tank
Up to 23 ft. (7 m) (without DHW recirculation line) + -
With DHW recirculation line - +
System retrofit DHW storage tank already installed - +
Replacement of existing Combi boiler + -
Space requirements Minimal space available (installation in alcove) + 0
Adequate space available (boiler room) + +
+ (recommended)
0 (recommended in certain cases)
- (not recommended)
Such factors are:
gDHW requirement, level of comfort and convenience
gNumber of draw points
gDistance of draw points from the boiler/DHW storage tank
gSystem retrofit
gSpace requirements

14
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Heating circuit pumps (continued)
Operation
Legend
ADHW output temperature
BDHW/DCW mixing zone
CDHW output temperature at the tap
DMax. flow (restriction by flow limiter)
Domestic Hot Water Production via Instantaneous DHW Plate Heat Exchanger (CombiPLUS)
The CombiPLUS is equipped with an electronically controlled instantaneous DHW plate heat exchanger.
The comfort control function (if selected) ensures that the instantaneous DHW plate heat exchanger is kept warm.
This translates into immediate availability of domestic hot water at any required temperature level.
Technical Data DHW Plate Heat Exchanger
See page 5 in this manual for technical data.
DHW supply temperature for WB1B 35 (with mixed water)
DHW supply temperature (ºF)
DHW flow rate (GPM)
DHW supply temperature (ºF)
DHW flow rate (GPM)
DHW supply temperature for WB1B 26 (with mixed water)
CombiPLUS heat exchanger performance
This chart illustrates the changes in the outlet temperature,
subject to the flow rate at the tap.
If greater volume (max. flow rate through heat exchanger=
2.6 GPM) of water is required, cold water needs to be
mixed which reduces the outlet temperature.
Curve is only applicable for a DCW inlet temperature of
56º F and a boiler input of 91,000 MBH (Vitodens 100-W,
WB1B 26).
Max. recovery rate @ DHW temperature of 140º F = 1.7 GPM
Min. flow through the heat exchanger for boiler start= 0.4 GPM
This chart illustrates the changes in the outlet temperature,
subject to the flow rate at the tap.
If greater volume (max. flow rate through heat exchanger=
3.6 GPM) of water is required, cold water needs to be
mixed which reduces the outlet temperature.
Curve is only applicable for a DCW inlet temperature of
56º F and a boiler input of 118,000 MBH (Vitodens 100-W,
WB1B 35).
Max. recovery rate @ DHW temperature of 140º F = 2.4 GPM
Min. flow through the heat exchanger for boiler start= 0.4 GPM
DHW supply temperature (ºF)
DHW flow rate (GPM)
DHW supply temperature for WB1B 35 (with mixed water)
This chart illustrates the changes in the outlet temperature,
subject to the flow rate at the tap.
If greater volume (max. flow rate through heat exchanger=
3.4 GPM) of water is required, cold water needs to be
mixed which reduces the outlet temperature.
Curve is only applicable for a DCW inlet temperature of
40º F and a boiler input of 118,000 MBH (Vitodens 100-W,
WB1B 35).
Max. recovery rate @ DHW temperature of 140º F = 2.14 GPM
Min. flow through the heat exchanger for boiler start= 0.4 GPM

15
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Start-up and Maintenance
Start-up and Maintenance
Mounting
Domestic Hot Water Production via DHW Storage Tank
Vitodens 100-W boilers can be used in conjunction with
the stand-alone DHW storage tanks offered by Viessmann
(a separate DHW controller should be field supplied).
All Viessmann DHW storage tanks sold in North America
are available in “Vitosilver” finish only.
Size and select the DHW storage tank based on the
forecast DHW consumption of the building in question.
For further technical information on DHW storage tanks,
see the Vitocell-V Technical Data Manuals.
Wall Mounting Information
The Vitodens 100-W (model WB1B 26 and 35) comes with
a template, which allows you to easily mark the location
of the screws for the mounting bracket and the location
of the flue gas pipe on the wall (Viessmann coaxial PPS
vent system only).
The connection to the heating circuits must be made on
site (installation fittings are supplied in the Installation
Fittings package supplied with the boiler).
Legend
ABoiler mounting template
Legend
ABoiler mounting template
BCombiPLUS mounting template
Mounting Vitodens 100-W boiler Mounting Vitodens 100-W boiler and the CombiPLUS
Installation

16
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Condensate Connection
Install the condensate drain pipe (Ø 7/8” / 22 mm) with
a suitable gradient (min. 2.5%).
Discharge condensate from the boiler into the drainage
system, either directly or (if required) via a neutralization
unit (accessory).
Condensate connection for Vitodens 100-W
gmodel WB1B 26, 35
Pipe ventilation must take place between the siphon trap
and the neutralization unit (if applicable).
IMPORTANT
Condensate Drainage and Condensate Neutralization
The condensate formed both in the condensing boiler and
in the flue gas pipe must be discharged into the public
sewage system in accordance with all applicable local
regulations. The condensate produced by a gas-fired
heating system has a pH value between 3 and 4.
Some local codes may require the use of a separate
neutralization unit to treat the aggressive and corrosive
condensate.
With a neutralization unit installed, all condensate from the
boiler and the flue gas pipe enters into the neutralization
unit where it is treated and released into the public sewage
system with a safe pH value of above 6.5.
The use of neutralization granulate (performing the
neutralizing process) is dependent on the operation of the
heating system. To determine the required refill amount,
check granulate level several times during the first year
of operation. In some cases one granulate fill may last
an entire year.
Contact Viessmann to order a neutralization unit for the
Vitodens 100-W boiler.
See Viessmann Price List for order information.
The condensate discharge outlet to the drainage system
connection must be clearly visible. It must be installed with
a suitable gradient and provided with a stench trap.
If the condensate outlet of the Vitodens 100-W boiler is
lower than the drain, a condensate pump must be used.
Only corrosion-resistant materials may be used for
condensate drainage purposes (e.g. braided hose).
Do not use galvanized materials or materials containing
copper for piping, couplings etc. The condensate drain
must have a trap.
Please note that other requirements may apply depending
on local regulations and/or project-specific details.
It is advisable to contact your local waterworks office
(authority responsible for waste water regulations)
well before commencing with the installation of the
neutralization unit in order to establish details of local
regulations that apply.
The following table shows the concentration of (effluent)
substances (e.g. heavy metals) contained in the waste
water from the Vitodens 100-W condensing boiler.
The condensate drain of the Vitodens 100-W boiler is
equipped with a built-in siphon trap in order to keep flue
gases from being discharged via the condensate drain.
Condensate
(effluent) substances
Values measured
in mg/L Vitodens 100
Lead
Cadmium
Chromium
Copper
Nickel
Zinc
Tin
< 0.01
< 0.005
< 0.01
< 0.01
< 0.01
< 0.05
< 0.05
ADischarge tubing
Installation
Condensate

17
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Start-up and Maintenance
Start-up and Maintenance
Vitodens 100-W Venting Options
For detailed information refer to the Vitodens Venting
System Installation Instructions.
Electrical Connection
All electrical connections are made to the boiler’s
integrated power pump module (120 VAC/60 Hz).
Use disconnect means and power service switch
as per local code requirements.
Control Unit
Function and construction:
The control is integrated into the Vitodens 100-W boiler.
gIntegrated diagnostic system
gFor room temperature-dependent operation,
an external control or a room temperature thermostat
may be connected
gTo control DHW temperature, a separate DHW
controller may be connected
gExternal heat demand
g0-10 V (with open therm only)
gViessmann outdoor temperature sensor (field wiring)
gOpen Therm (field wiring)
gCombiPLUS instantaneous DHW control
The control unit consists of:
gLCD Display
gSelector dial for boiler water temperature adjustment
gSelector dial for service setting
gTemperature adjustable high limit
gBoiler temperature sensor
gBurner fault display
gBurner fault reset
gPressure gage
gFuse
Boiler temperature sensor
The boiler temperature sensor is connected to the control
unit and built into the boiler.
Frost protection
Frost protection is continuously active. The burner is
switched ON when the boiler water temperature reaches
41° F (5° C) and is switched OFF again when the boiler
water temperature reaches at least 59° F (15° C)
[but not more than 68° F (20° C)].
For details on the control, refer to the
Vitodens 100-W Operating Instructions.
Venting Options / Electrical Connections
Installation

18
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
IMPORTANT
Accessories for the Vitodens 100-W
Neutralization Unit for Single-Boiler Applications
with neutralizing granulate for Vitodens 100-W, WB1B 26, 35
Part No. 7134 231
Low-Loss Header
- Type 80/50, Part No. 7134 791
[max. flow rate 17.6 GPM (4 m3/h)]
- Type 120/80, Part No. 7134 792
[max. flow rate 35.2 GPM (8 m3/h)]
A low-loss header offers additional benefits
not provided by a pair of closely spaced
tees. Viessmann strongly recommends
and prefers the use of a low-loss header
over closely spaced tees. When used in
conjunction with the Vitodens 100-W
boiler, the low-loss header acts as
hydraulic break, decoupling boiler and
system circuits from each other (no
sensor required). It is recommended to
use the low-loss header in applications in
which the total system flow rate exceeds
the maximum or falls below the minimum
flow rate of the Vitodens 100-W boiler.
Product may not look exactly as illustrated.
The low-loss header is available in the following sizes.
Select the size based on the maximum system flow rate
of your application.
Legend
Vprimary Boiler circuit flow rate
Vsecondary Heating circuit flow rate
Vbypass Bypass flow rate
Qprimary Heat supplied by boiler
Qsecondary Heat consumed by system
Vprimary < Vsecondary
T1 > T3
T2 = T4
Qprimary = Qsecondary
T1 176° F (80° C)
Vsecondary=Vprimary+Vbypass
When installing a low-loss header, system mixed supply
temperature (T3) must be calculated as follows
For maximum boiler flow rates, see the table on page 11
in this manual.
Viessmann strongly recommends the use of a low-loss
header in cases where the system head and flow rates
are unknown.
In addition, the low-loss header helps eliminate air and
debris [D] from the heating system. See illustrations for
Low-loss header design and the principle of operation.
Product may not look exactly as illustrated.
Low-loss header design
Prinicpal of operation
Vprimary Vbypass Vsecondary
AB Air Bleed DV Drain Valve
BR Boiler Return SR System Return
BS Boiler Supply SS System Supply
BY Bypass
(with laminar flow)
TS Viessmann Temp.
Sensor (not used)
D Debris and/or air SW Sensor Well
T1 Boiler supply temp. T3 System supply temp.
T2 Boiler return temp. T4 System return temp.
Model No. Max. system flow rate
Type 80/50 17.6 GPM (4 m3/h)
Type 120/80 35.2 GPM (8 m3/h)
Installation
Accessories

19
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Standard Equipment
The Vitodens 100-W gas-fired condensing boiler with
Inox-Radial heat exchanger surfaces, modulating stainless
steel MatriX cylinder gas burner c/w:
ginstallation fittings with 30 psig pressure relief valve,
air vent and pressure gauge
gtwo fill/drain valves
gall mounting hardware
The boiler comes fully piped and pre-wired.
Venting material (coaxial) or single pipe PP(s) is to be
supplied by Viessmann only. Side wall vent installations
must include Viessmann protective screen!
Wall mounting componentry
The following wall mounting components are supplied with
the Vitodens 100-W boiler:
gMounting bracket
gMounting bolts
gInstallation fittings
gScrews for mounting bracket on
- wood studs (2” x 4”)
- metal studs
- brick/concrete wall
How the Vitodens 100-W boiler operates...
The Vitodens 100-W boiler uses a premix combustion
system, which is designed to deliver a certain air-gas
mixture to the burner for complete combustion. The gas
is injected upstream of the blower. The burner and heat
exchanger are part of a forced-draft design. The benefits
of forced-draft systems are lower component
temperatures, direct air-fuel connection (premix) for
improved mixing, and longer service life of the boiler due
to mild to moderate ambient conditions.
The MatriX cylinder burner, blower and the combination
gas valve are factory calibrated and pre-adjusted. A
pneumatic link between combustion air and gas flows
guarantees optimal boiler performance at all firing rates.
Blower speed is automatically increased or decreased
based on heat demand, thereby regulating the amount
of combustion air drawn. The pneumatic link between air
and gas introduces the required amount of gas for optimal
combustion to meet the current heat demand, based on
a linear relationship between ∆P air and ∆P gas.
Installation Examples
The examples on the following pages depict possible
piping layouts of the Vitodens 100-W boiler.
Please note that the following examples are simplified
conceptual drawings only!
Piping and necessary componentry must be field
verified. A low water cut-off (LWCO) must be installed
where required by local codes. Proper installation and
functionality in the field is the responsibility of the heating
contractor.
IMPORTANT
Installation
Standard Equipment

20
5601 189 v1.1
Vitodens 100-W, WB1B Technical Data
Vitodens 100-W, WB1B 26, 35 with one heating circuit
(without optional CombiPLUS)
System Layout 1 (alternate option)
Legend
AV Air vent
PRV Pressure relief valve
AVitodens 100-W
BRoom thermostat
CHeating circuit
DHeating circuit pump (field supplied)
EExpansion tank
FPressure Activated By-Pass
Model WB1B 26 35
∆t
Output Btu/h 83,000 108,000
30° F rise (GPM) 5.5 ---
35° F rise (GPM) 4.7 6.2
40° F rise (GPM) 4.2 5.4
Note: The use of a low-loss header is recommended if the
water flow rate is less than 1.7 GPM (400 L/h) or
more than 6.2 GPM (1400 L/h).
The low-loss header is available as accessory part.
Note: Heating circuit C in the examples should be designed
to 30º F to 40º F (16.7º C to 22.2º C). For lesser
delta T design, system layout designer must use
one of the examples (3 or 4) on the following pages.
Maximum Flow Rates
Ensure that a pressure activated by-pass is installed if
there are system component(s) in Cthat may isolate the
flow to the pump D.
IMPORTANT
System Layout 1
Installation
AV
PRV
AV
PRV