Viessmann Vitotron 100 Quick guide

Installation and Service
Instructions
VITOTRON 100
5472 726 - 04 11/2022
For use by heating contractor
Please file in Service Binder
Read and save these instructions
for future reference.
Product may not be exactly as shown
IMPORTANT
Vitotron 100 VLN2
Models 04 to 14.4
Wall-mounted Electric Boiler
Heating input: 13.6 to 49.1 MBH
4.0 to 14.4 kW

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Vitotron 100 Electric Boiler Installation/Service
Safety Instructions .....................................................3
Electric Boiler Ratings and Specification ...................... 4
Electric Boiler Mounting Clearances ..............................5
Piping Arrangement....................................................6
Sizing the Electric Boiler ..............................................7
Designed Temperature Differential ..............................7
Circulating Pump Information ......................................7
Plumbing Installation Guidelines ...................................8
Electrical Installation.................................................10
Control Panel ...........................................................12
Heating Mode / Initial Start-Up ...................................13
Winter Mode (Heating Mode) .......................................13
Summer Mode (Stand-by Mode)....................................16
Advanced Settings ...................................................17
Troubleshooting .......................................................18
Care and Maintenance ..............................................18
General View of the Electric Boiler..............................19
Parts List.................................................................20
Electric Boiler Parts...................................................21
Instructions for the Installer
Instructions for the User
Page
Table of Contents
This appliance is not intended for use by persons
(including children) with reduced physical, sensory or
mental capabilities or lack of experience and knowledge,
unless they have been given supervision or instruction
concerning use of the appliance by a person responsible
for their safety. Children should be supervised to ensure
that they do not play with the electric boiler appliance.
Consider all piping and electrical connections before
selecting electric boiler location.
Failure to follow the instructions in this manual could
result in severe personal injury, death or property damage.
IMPORTANT

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Vitotron 100 Electric Boiler Installation/Service Instructions for the Installer
Safety Instructions
8. This electric boiler is equipped with a 194°F manual
reset safety high limit device. The reset button is
clearly located in the center of this device.
9. This electric boiler will not operate below a 7 psi
water pressure level.
10. This electric boiler is equipped with a Wilo circulator
pump. After thermostat temperature set point has
been reached the pump will continue to
circulate water for 3 additional minutes as part of a
post purge sequence to push heated water away from
heat exchanger.
11. This electric boiler is equipped with a differential
pressure relief bypass valve. It allows the system
to keep minimal flow of heating water through
the electric boiler and reduce noise in the installation
when equipped with thermostatic zone valves.
12. Do not drain the water from the electric boiler after
the heating season.
13. In summer do not shut off the power supply (120VAC
and 240VAC) and leave the controller in stand-by
(summer mode) between the heating seasons. The
electric boiler is equipped with an exercise timer
control feature that allows the circulating pump to
operate 15 minutes each day and will ensure longer
operation the circulating pump and will help to
eliminate the buildup of debris. (See section “Summer
mode (stand-by mode)”on page 11).
14. The electric boiler is pre-set by the manufacturer to
work with hydronic radiant floor, radiant ceiling,
hot water baseboard and water to air heat
applications. Temperature adjustments can be made
on the control panel to meet these applications
requiring desired water temperatures between 85° -
140°F.
1. Read and strictly follow the installation and operating
instructions to ensure a longevity and reliable electric
boiler operation.
2. This manual provides general installation guidelines.
Your installation must comply with ALL applicable
local codes.
3. 1Always have a qualified electrician perform
electrical wiring. Manufacturer will not be held
responsible for faulty installations which are performed
by unqualified electricians. An efficient electrical
installation which has been completed in accordance
with the binding norms of electric installation.
Electric installation should be equipped with electric
circuit breakers and other solutions which will ensure
disconnecting the electric boiler from the source of
power.
4. All installation work must be performed when the
power and water supply is disconnected from the
main electrical panel.
5. This electric boiler must be installed vertically and on
an even wall surface with access to plumbing
connections on bottom.
6. Any associated components (i.e. electric boiler,
water tubing, valves, manifolds etc...) must be
flushed before electric boiler installation.
7. This electric boiler is equipped with a safety relief
valve. Do not install any barrier fitting or valve on the
outlet of the safety valve. Connect and extend
cin. copper piping from relief valve and terminate
at least 6 in. from the floor or floor drain.

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Vitotron 100 Electric Boiler Installation/Service
Instructions for the Installer
Electric Boiler Ratings and Specifications
Electric Boiler Model VLN2 04 VLN2 06 VLN2 08 VLN2 12 VLN2 14.4
Electric Boiler
Rated Power
kW 4 6 8 12 14.4
Btu/h 13,652 20,478 27,304 40,956 49,147
Voltage V 240
Rated Current A 16.66 25.0 33.3 50.0 60.0
Breaker Quantity-
Amps
A 1 @
30 amp
1 @
40 amp
1 @
50 amp
1 @
60/70 amp
1 @
80 amp
Heating Elements Quantity 3
Element Resistance
/ each
Ω43.3 28.8 21.6 14.4 12.0
Circulating Pump - Wilo Star S 21 U 15. 3 speed
Circulating Pump
Voltage
V 120V, 60Hz
Circulating Pump
Amps
A .97
Speeds 3
Fuse Rating 2.0 amp
Operating
Temperature Range
°F 85° - 140°
Inlet / Outlet
Pipe Thread
G cin. (Internal Thread)
Expansion Vessel
(14 psi)
Gallon 1.6
Safety Relief Valve
Rating
psi 30
Maximum Pressure psi 30
Minimum Pressure psi 7
Weight Lbs. 68.5
Dimensions
L x W x D
Inches 28 x 17 x 97/8
Minimum Flow Rate gpm 1.1 1.32

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Vitotron 100 Electric Boiler Installation/Service Instructions for the Installer
Electric Boiler Mounting Clearances
After reading instructions, please keep this manual with
the electric boiler for future reference. Affix the plastic
holder to the outside of the electric boiler and insert
manual in this pocket.
IMPORTANT

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Vitotron 100 Electric Boiler Installation/Service
Piping Arrangement
Instructions for the Installer
Typical radiant floor heating application
1Electric Boiler
2Additional expansion tank - if needed
Electric boiler piped in a primary/secondary (P/S)
configuration. Consider P/S when higher flow rates are
necessary and when the electric boiler meets the intended
heatloss of the hydronic system.
1Electric Boiler
2Additional expansion tank - if needed
3Low loss header

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Vitotron 100 Electric Boiler Installation/Service
Sizing of the Boiler
Instructions for the Installer
It is very important to conduct a heatloss analysis of
the intended heated space. Select the electric boiler size
in kW based on its Btu/hr. rating that best meets the
designed heatloss.
It is important not to overly exceed the kW sizing as
this will lead to unnecessary costs of electric boiler, wiring
and materials. Consequentially it is extremely imperative
NOT to undersize the electric boiler.
How to choose the correct electric boiler size? Convert
BTU to kW by dividing the BTU load by 3,413.
(Ex. 33,513 BTU / 3,413 = 9.81kW). Choose a electric
boiler that slightly exceeds this kW requirement by no
more than 20%.
For larger BTU loads consider cascading the electric
boilers together and pipe the system in a parallel
configuration as described in the piping arrangement
section.
Note: that utilizing propylene glycol freeze protection will
reduce the heat transfer and cause the system to
be less efficient. Under no circumstance should
more than a 50/50 ratio of water to propylene
glycol be used. Consult with radiant system
designers for required freeze protection guidelines.
Designed Temperature Differential
Radiant floor heating systems are typically designed for a
10°- 20°F temperature differential determined by when
the heating fluid leaves the electric boiler and where it
enters the radiant heat source. i.e. radiant PEX/tubing.
Circulating Pump Information
This electric boiler is equipped with a Wilo Star S 21 U
15, 3 speed circulating pump. To determine the speed or
setting of the pump, confirm with radiant design completed
by others and or complete a pressure-loss calculation.
Refer to calculations of loop lengths to determine proper
speed. The pump will automatically operate based on a
thermostat call for heat. After the thermostat temperature
set point has been reached, the pump will continue to
circulate water for 3 additional minutes as part of a post
purge operation to push heated water away from the heat
exchanger.
This electric boiler is also equipped with an additional
pump relay. This will aid the installer if there is any need
to pipe the systems with a secondary circulating pump to
overcome pressure drop due to piping or hydronic tubing
design. This is commonly referred to as primary/secondary
applications described in the piping arrangement section.

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Vitotron 100 Electric Boiler Installation/Service
Plumbing Installation Guidelines
Instructions for the Installer
1. Remove outer screws at the bottom and at the top
of electric boiler and carefully open the front cover.
2. The electric boiler is wall hung and must be installed
in a vertical position where plumbing connections are
located at the bottom. Utilize key holes slots to hang
the electric boiler. Refer to diagram on clearances
(page 5).
3. The electric boiler is provided with a e in. air vent
located on top of the heat exchanger. It is designed to
collect and remove air. Ensure plastic drain tubing
remains in place and exits the electric boiler in the
lower right corner.
4. The electric boiler is equipped with a pre-charged flat
expansion tank located on the back housing of the
electric boiler. Expansion tank has a Shrader valve,
which location is shown on the figure. This figure
presents the bottom view of the electric boiler.
Access to the valve is only from the bottom of
the electric boiler. From there it can be connected any
pressure gauge to check the pressure or pump to refill
the air inside the tank.
5. The electric boiler is equipped with an ASME
approved 30 psi automatic safety pressure relief
valve. Install the necessary length of cin. copper
piping from the relief valve to within 6 in. of the floor
to prevent personal injury or water damage to
surrounding area.
6. Observe inlet return piping (blue label) and outlet
supply feed piping (red lable) connections. Install
shutoff valves below inlet and outlet connections
before plumbing the electric boiler to the hydronic
heating system.
DO NOT reverse these connections to the radiant
supply and return manifolds. Optional temperature
or pressure gauges can be installed below the electric
boiler if desired.
7. Install boiler drain valve(s) as necessary to aid in
filling, purging and draining of unit and the related
system components.
8. Water supply feed or pressure reducing valve can
be installed to comply with local building codes.
Local codes may require a back flow preventer called
a check valve when installing a fixed domestic water
supply line to the electric boiler.

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Vitotron 100 Electric Boiler Installation/Service
Plumbing Installation Guidelines (continued)
Instructions for the Installer
9. When possible, fill the electric boiler and hydronic
system with treated water. (i.e. soft or distilled
water) This will substantially extend the life of the
heating elements and reduce sediment buildup.
10. Freeze protection additives can be added. Only use
propylene glycol type freeze protection products for
hydronic heating systems that are non-toxic and
corrosion resistant.
The propylene glycol mix shall not exceed 50%, by
volume. 1 Under no circumstance should methanol
or ethylene glycol (automobile antifreeze) be added
to the electric boiler system as this may damage
internal components.
11. Insure purging of all air throughout electric boiler
system and related components.
12. This electric boiler requires a minimum
pressure of 7 psi in order to operate. Pressure levels
for hydronic systems typically are above the pre-
charged expansion tank pressure level (12 psi).
If additional pressure gauges are installed verify
reading as described on item 7.
13. The electric boiler is equipped with a pressure
differential bypass valve. This allows the minimum
flow rate to pass through the electric boiler when all
zone valves are closed. The valve will also help
reduce noise issues upon closing of zone valves or
actuators.
To adjust:
Turn differential bypass valve clockwise until it stops.
Turn on all heating zones and let them heat for a
couple of minutes.
Caution! piping can get hot quickly upon opening
the valve. Slowly open the bypass valve by turning
in a counter clock wise direction.
Stop turning once an increase in temperature is felt
on the outlet side of the valve. This is referred to the
tipping point. After reaching the tipping point continue
to turn the valve one complete turn. The valve is now
set to bypass excess flow as zone valves close.
Set the thermostats to normal set temperatures.
14. Proceed to the Electrical Installation.

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Vitotron 100 Electric Boiler Installation/Service
Electrical Installation
Instructions for the Installer
For supply connections, use 10 awg or larger wires
suitable for at least 167°F (75°C)
1. All electrical work should be completed in accordance
to local or state electrical and building codes.
2. This electric boiler must be electrically grounded in
accordance with National Electrical Code ANSI/
NFPA70, or local codes.
3. This electric boiler operates with 240VAC single
phase electrical power source.
4. Connect the electric boiler to the electrical service
using 1COPPER WIRE ONLY. Tighten connections
by using a 3/16 in. Hex key tool. Conform to local
electrical codes for correct sizing of electrical breakers
and size of electric conductor wires. Refer to electric
boiler nameplate for current and kW ratings. Local
electric codes may require an electrical disconnect.
Electrical Wiring Diagram