Viessmann VITOTRONIC 100 User manual

for use by heating contractor
Read and save these instructions
for future reference.
Please file in Service Binder
Product may not be exactly as shown
5793 310 - 02 02/2015
VITOTRONICr100
VITOTRONICr300-K
Vitotronic 100, type GC1B
Multi boiler system with control unit for constant temperature operation
For use with Boiler models VD2A, VD2 and CT3
Vitotronic 300-K, type MW1B
Weather-compensated cascade control
Operating Instructions
IMPORTANT
Certified as a component
part for Viessmann boilers
Vitotronic 300-K
Vitotronic 100

5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
General
Safety, Installation and Warranty Requirements
Please ensure that these instructions are read and understood before commencing installation. Failure to comply with
the instructions listed below and details printed in this manual can cause product/property damage, severe personal
injury, and/or loss of life. Ensure all requirements below are understood and fulfilled (including detailed information
found in manual subsections).
WARNING
Installers must follow local regulations with respect to
installation of carbon monoxide detectors. Follow the
Viessmann maintenance schedule of the boiler contained
in this manual.
Product documentation
Read all applicable documentation before commencing
installation. Store documentation near boiler in a
readily accessible location for reference in the future
by service personnel.
For a listing of applicable literature,
please see section entitled “Important
Regulatory and Safety Requirements”.
Warranty
Information contained in this and
related product documentation must
be read and followed. Failure to do
so renders the warranty null and void.
Licensed professional heating contractor
The installation, adjustment, service and maintenance
of this equipment must be performed by a licensed
professional heating contractor.
Please see section entitled
“Important Regulatory and Installation
Requirements”.
Operating and Service Documentation
It is recommended that all product documentation such
as parts lists, operating and service instructions be
handed over to the system user for storage.
Documentation is to be stored near boiler in a readily
accessible location for reference by service personnel.
Advice to owner
Once the installation work is complete, the heating
contractor must familiarize the system operator/
ultimate owner with all equipment, as well as safety
precautions/requirements, shutdown procedure, and
the need for professional service annually before the
heating season begins.
2

Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
3
5793 310 - 02
General
Commissioning
Your System is Preset at the Factory
Your local service technician will also inform you [where
appropriate] about work he may be required to perform
on your combustion equipment (e.g. regular checks,
cleaning).
The control units are factory-set for central heating and
DHW heating:
Vitotronic 300-K: “Heating and DHW”
Your heating system is therefore ready for use.
Central heating
Between 06:00 and 22:00 h, the rooms are heated
to 68° F (20° C) “Set room temperature” (standard
heating mode).
Between 22:00 and 06:00 h, the rooms are heated
to 37° F (3° C) “Set red. room temp” (reduced heating
mode, frost protection).
Your heating contractor can make further settings for
you during commissioning. You can change any
settings individually at any time to suit your
requirements (see chapter “Central heating”).
DHW heating
Between 05:30 and 22:00 h, DHW is heated to 122° F
(50° C) “Set DHW temperature”. Any installed DHW
circulation pump is on.
Between 22:00 and 05:30 h, the DHW cylinder
temperature will not be reheated. Any installed DHW
circulation pump is off.
Your heating contractor can make further settings for
you during commissioning. You can change any
settings individually at any time to suit your
requirements (see chapter “DHW heating”).
Frost protection
Your boiler, heating circuits and DHW cylinder are
protected against frost. Wintertime/summertime
changeover
This changeover is automatic.
Time and date
The day and time were set by your heating contractor
during commissioning.
Power failure
All data is saved if there is a power failure.
The commissioning and matching of the control unit to
local conditions and building characteristics, as well as
instructing the user in the operation of the system, must
be carried out by your heating contractor. As the user of
new combustion equipment, you may be obliged to notify
your local service technician of the installation [check
local regulations].
Terminology
To provide you with a better understanding of the
functions of your control unit, the appendix contains
the chapter “Terminology” (see page 40).

4
Page
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
5793 310 - 02
General
Safety
Operation
Start-up/Shutdown
Central Heating
Comfort and Energy Saving Functions
DHW Heating
Further Adjustments
Safety, Installation and Warranty Requirements..............2
Commissioning..........................................................3
Your System is Preset at the Factory.............................3
Terminology..............................................................3
For your Safety......................................................6
Where to Find the Controls..........................................7
Controls, Vitotronic 100..............................................7
How to use the Controls, Vitotronic 100.......................8
.
Controls, Vitotronic 300-K..........................................9
Menu, Vitotronic 300-K.............................................10
How to use the Controls, Vitotronic 300-K..................11
Starting the Heating System.......................................12
Stopping the Heating System.....................................13
Required Settings (Central Heating).............................14
Selecting a Heating Circuit.........................................14
Setting the Room Temperature...................................15
Setting the Heating Program for Central Heating...........15
Setting the Time Program for Central Heating...............16
..
Changing the Heating Curve.......................................17
Stopping Central Heating...........................................17
Selecting Comfort Function “Party Mode”...................18
Selecting Energy Saving Function “Economy Mode”......18
Selecting Energy Saving Function “Holiday Program”....19
Required Settings (DHW Heating)................................20
Setting the DHW Temperature....................................20
Setting the Heating Program for DHW Heating..............20
Setting the Time Program for DHW Heating.................21
Stopping DHW Heating..............................................22
Selecting the Boiler Sequence.....................................23
Setting the Display Contrast.......................................23
Setting the Display Brightness....................................23
Entering Names for the Heating Circuit........................24
Setting the Time and Date.........................................25
Language Selection...................................................25
...
Setting the Temperature Unit (oC/oF)...........................25
Restoring Factory Settings.........................................26
Table of Contents

Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Table of Contents
5
Page
5793 310 - 02
Scanning Options
Troubleshooting
Maintenance
Additional Information
Scanning Information.................................................27
Scanning Service Messages........................................29
Scanning Fault Messages...........................................29
Emissions Test Mode................................................31
Rooms are Too Cold.................................................32
Rooms are Too Hot...................................................33
There is No Hot Water...............................................33
The DHW is Too Hot.................................................34
“Off” is Displayed at the Vitotronic 100......................34
“” is Displayed at the Vitotronic 100........................34
..
“ “ is Displayed at the Vitotronic 100.......................34
..
“ “ Flashes and “Fault” is Displayed at the
Vitotronic 300-K......................................................34
“Controls Locked Out”is Displayed at the
Vitotronic 300-K.......................................................35
“External Hook-up” is Displayed at the
Vitotronic 300-K.......................................................35
“Central Control” is Displayed at the
Vitotronic 300-K.......................................................35
“External Program” is Displayed at the
Vitotronic 300-K.......................................................35
Maintenance............................................................36
Menu Overview, Vitotronic 300-K..............................37
Terminology............................................................40

5793 310 - 02
6
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
If you smell gas
HDon’t smoke! Don’t use naked flames or cause sparks
(e.g. by switching lights or electrical appliances on
and off)
HOpen windows and doors
HClose the gas shut-off valve
HInform your heating engineers/service contractors from
outside the building
HObserve the safety regulations of your gas supply
company (see gas meter) and those of your heating
engineers (see start-up or instruction report).
In emergencies
HImmediately switch off the power supply, e.g. at the
separate fuse or power supply disconnect switch
(unless there is a smell of gas).
HClose the shut-off valves in the oil pipes or close the
gas shut-off valve, whichever applicable.
HUse suitable extinguishers in the event of fire.
Installation of additional components
The installation of additional components which have not
been tested together with the boiler can adversely affect
the function and performance of the boiler.
Our warranty does not cover and we accept no liability
for damage attributable to the installation of such
components.
Boiler room conditions
HDo not use a room in which the air is polluted by
halogenated hydro-carbons (e.g. as contained in
aerosols, paints, solvents and cleaning agents)
HDo not use a room subject to high levels of dust
HDo not use a room subject to permanently high humidity
HThe room should be frost-protected
HMax. ambient temperature 95° F (35° C).
HProvide good ventilation and do not close or obstruct
vents (if installed).
Safety
CAUTION
Follow these safety instructions closely to avoid the risk
of injury and damage to property.
For your Safety (continued)
HOperation
Before operating the boiler, make sure you fully
understand its method of operation. Your heating
contractor should always perform the initial start-up
and explain the system. Any warranty is null and void
if these instructions are not followed.
HFlue gas smell
- Deactivate heating equipment.
- Open windows and doors.
- Inform your heating contractor.
HWorking on the equipment
All personnel working on the equipment or the heating
system must have the proper qualifications and hold
all necessary licenses. Ensure main power to
equipment, heating system, and all external controls
has been deactivated. Close main gas supply valve.
Take precautions in all instances to avoid accidental
activation of power during service work.
HDangerous conditions
- Deactivate main power immediately.
- Close gas supply valve.
HMaintenance and cleaning
Regular inspection and service by a qualified heating
contractor is important to the performance of the boiler.
Neglected maintenance impacts on warranty; regular
inspection ensures clean, environmentally friendly and
efficient operation. We recommend a maintenance
contract with a qualified heating contractor.
HTechnical Data Manual
- Installation Instruction and Service Instructions
- Operating Instructions and User’s Information Manual
Additional applicable literature:
- Accessory manuals
This symbol indicates a reference to other
instructions which must be observed.

7
5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Operation
Where to Find the Controls
Each boiler is equipped with its own control unit for
constant temperature operation.
These control units are regulated by a higher weather-
compensated cascade control unit.
HControl unit for constant temperature operation on the
boiler: Vitotronic 100
HHigher weather-compensated cascade control unit:
Vitotronic 300-K
You can change all settings for your heating system
centrally at the control unit programming unit.
You may also make such changes at the remote control
units, if your system is equipped with such units.
The settings at the Vitotronic 100 are described in these
operating instructions. You do not need the operating
instructions provided with these control units.
Controls, Vitotronic 100
The programming unit is located behind the flap.
To open, pull the flap from the top edge forward.
Refer to the Remote control Operating Instructions
Legend
ACover flap
Opening the Vitotronic 100, type GC1B control unit
Takes you to the previous step in the menu or cancels
a setting that has been started.
Cursor keys
To scroll through the menu or to set values.
Programming unit
OK Confirms your selection or saves the setting.
? No function.
Enables you to call up the menu for settings and
scanning.

5793 310 - 02
8
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
How to Use the Controls, Vitotronic 100
Operation
Symbols
These symbols are not always displayed, but appear
subject to the system version and the operating state.
Flashing displays indicate that modifications can be made.
Menu
Information
Further adjustments
S Emissions test mode
Heating program
9 Standby mode with frost protection monitoring
The boiler is available to the cascade control unit for
heat production.
Note: If a boiler is not operational, the following appears
in the display of the corresponding control unit:
In multi boiler systems, each Vitotronic 100 indicates
the boiler number on the standard display. The following
example shows the boiler water temperature as indicated
by boiler 3.
Messages
Service message
u The service interval has expired.
 Fault message
Displays
pCirculation pump at output 20 is running
A Burner in operation
D Factory settings
Press .
This takes you to the menu for settings and scanning.

9
5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Operation
Controls, Vitotronic 300-K
Opening the Vitotronic 300-K, type MW1B control unit
The programming unit is located behind the flap.
To open, pull the flap from the top edge forward.
Menu “Help”
You can view a short guide giving an explanation of the
controls and information about heating circuit selection
(see page 14).
Call up the short guide as follows:
HIf the screen saver is active (see page 11):
Press ?
HFrom anywhere in the menu:
Press until the standard menu is shown (see the
following chapter).
Press ?
Legend
ACover flap
Programming unit
Takes you to the previous step in the menu or
cancels a setting that has been started.
Cursor keys
To scroll through the menu or to set values.
OK Confirms your selection or saves the setting.
? To call up additional information regarding the
selected menu option.
Calls up the extended menu.

5793 310 - 02
10
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
Menu, Vitotronic 300-K
Operation
There are two control levels available, the “Standard
menu” and the “Extended menu”.
The menu overview can be found on page 37.
Standard menu
Call up the standard menu as follows:
HIf the screen saver is active (see page 11)
Press OK.
HFrom anywhere in the menu:
Keep pressing until the standard menu appears.
In the standard menu, the number of boilers installed in
the heating system is shown in a specific order (boiler
sequence). You can change the boiler sequence
(see page 23).
The meanings of the icons are as follows:
HSolid white:
The boiler has been enabled by the cascade control unit
and is operating (boiler 3 in this example).
HSolid grey:
The boiler is available for generating heat but has not
been enabled by the cascade control unit (boilers 2 and
4 in this example).
HSolid black and crossed out:
This boiler is not available for heat production (boiler 1
in this example).
Note: 2 minutes after any setting has been made, the
display automatically reverts to the standard menu.
Extended menu
Call up the extended menu as follows:
HIf the screen saver is active (see page 11):
Press OK and then .
HFrom anywhere in the menu:
Press .
Note: Your heating contractor can block the use of the
extended menu. In this case, you can only scan
fault messages.
Legend
ADialogue line

11
5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Operation
How to Use the Controls, Vitotronic 300-K
1. Press OK. This takes you to the standard menu
(see page 37).
2. Press . This takes you to the extended menu
(see page 38). The selected menu option is
highlighted in white.
The dialogue line A(see diagram on page 10) then
shows the necessary instructions.
The following diagram shows how to make settings with
different dialogue lines, using the set room temperature
setting as an example.
The screen saver will become active if you have not
adjusted any settings on the programming unit for a few
minutes.
The display brightness is reduced.
How to Use the Controls, Vitotronic 300-K (continued)

5793 310 - 02
12
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
Start-up/Shutdown
Starting the Heating System
Legend
AON indicator (green)
BFault indicator (red)
CEmissions test switch
(only for service purposes)
DTest key
(only for service purposes)
EFixed high limit reset
FON/OFF switch
GAdjustable high limit
HFuses
1. Check that the combustion air openings of the
mechanical room are open and unrestricted.
Note: With room air dependant operation, the
combustion air is drawn from the mechanical
room.
2. Open the shut-off valves in the oil lines (at the tank
and filter) or open the gas shut-off valve.
3. Switch ON the power supply, e.g. at a separate MCB/
fuse or a mains isolator.
4. Switch ON the ON/OFF switches at all Vitotronic 100
and at the Vitotronic 300-K (see chapter “Controls”).
After a short time, the following is shown on the
display:
HVitotronic 100: the standard display (see page 8)
HVitotronic 300-K: the standard menu (see page 10)
The green ON indicator illuminates.
Your heating system and, if installed, your remote
control units are now ready to operate.
Note: On every Vitotronic 100, “ “ must be selected,
otherwise the Vitotronic 300-K cannot use the
corresponding boiler to produce heat.
Legend
AON indicator (green)
BFault indicator (red)
CEmissions test switch
(only for service purposes)
DON/OFF switch
EFuse
Vitotronic 300-K, type MW1B
control with cover flap open
control with cover flap open
Vitotronic 100, type GC1B

13
5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Start-up/Shutdown
Stopping the Heating System
With frost protection monitoring
At the Vitotronic 300-K, select the heating program
“Standby mode” for every heating circuit.
HNo central heating.
HNo DHW heating.
HFrost protection for the heating circuits and the DHW
tank is active.
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Heating program”
5. “Standby mode” (frost protection monitoring)
Note: The circulation pumps are briefly started every 24
hours to prevent them from seizing up.
Ending the heating program “Standby mode”
Select another heating program.
Stopping individual boilers at the relevant Vitotronic 100
Press the following keys:
1. for settings; “ “ flashes.
2. OK to confirm; “9 w “ flashes.
3. OK to confirm; “ w “ flashes.
4. 
until “9“ flashes.
5. OK to confirm.
Pump exercise function
Circulation pumps are started for 10 sec. once every 24
hours to prevent the pumps from seizing up. This function
is active during all operating programs and during warm
weather shutdown.
Ending the heating program “Standby mode”
Select another heating program.
Without frost protection monitoring (shutdown)
1. Switch OFF the ON/OFF switches at all Vitotronic 100
and Vitotronic 300-K (see chapter “Controls”).
2. Close the shut-off valves in the oil lines (at the tank
and filter) or close the gas shut-off valve.
3. Isolate the heating system from its main power
supply, e.g. at a separate MCB/fuse or a mains
isolator.
4. Where outside temperatures of below 37° F (3° C)
are anticipated, please take suitable measures to
protect the heating system against frost. If necessary,
contact your heating contractor.
Information on a prolonged shutdown
HCirculation pumps may seize up as they are not supplied
with power.
HVitotronic 300-K:
It may be necessary to reset the date and time
(see page 25).

5793 310 - 02
14
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
Central Heating
Required Settings (Central Heating)
Make the settings for central heating at the Vitotronic
300-K.
If you want central heating, check the following points:
HHave you selected the heating circuit?
For settings, see the next chapter.
HHave you set the required room temperature?
For settings, see page 15.
HHave you selected the correct heating program?
For settings, see page 15.
HHave you set the required time program?
For settings, see page 16.
Selecting a Heating Circuit
The heating of all rooms can, if necessary, be split over
several heating circuits.
HIn the case of heating systems with several heating
circuits, for all central heating settings, first select the
heating circuit where you want to make a change.
HThis selection is not possible in heating systems with
only one heating circuit.
Example:
H“Heating circuit 1” is the heating circuit for the offices
on the ground floor.
H“Heating circuit 2” is the heating circuit for the offices
on the first floor.
The heating circuits are marked at the factory as “Heating
circuit 1” (HC1), “Heating circuit 2” (HC2) and “Heating
circuit 3” (HC3).
If you or your heating contractor have renamed the
heating circuits (e.g. as “Ground floor” etc.), the name
is displayed instead of “Heating circuit ...” (see page 24).
In the extended menu, you can scan the selected heating
program under “Information” (see chapter “Scanning
information”, “Heating circuit ...” group).
Extended menu
1.
2. “Heating”
3. for the required heating circuit.

15
5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Central Heating
Setting the Room Temperature
Setting the room temperature for reduced heating mode
(night setback)
Factory setting: 37° F (3° C)
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Set red. room temp”
5. Set the required value.
The rooms are heated to this temperature:
HBetween the time phases for standard heating mode
(see page 16).
HIn the holiday program (see page 19).
Setting the room temperature for standard heating mode
Factory setting: 68° F (20° C)
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Set room temperature”
5. Set the required value.
Setting the Heating Program for Central Heating
Factory setting: “Heating and DHW”
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Heating program”
5. “Heating and DHW”
HThe rooms of the selected heating circuit are heated
in accordance with the room temperature and time
program settings.
HDHW is reheated in accordance with the set DHW
temperature and time program (see chapter “DHW
heating”).

5793 310 - 02
16
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
Central Heating
Setting the Time Program for Central Heating
HThe time program for central heating is made up of time
phases. One time phase from 6:00 to 22:00 h for every
day of the week is set at the factory.
HYou can set the time program individually, to be
the same for every day of the week or different:
You can select up to 4 time phases per day for standard
heating mode. Set the start and end points for each
time phase. Between these time phases, the rooms are
heated with the reduced room temperature (see chapter
“Setting the room temperature for reduced heating
mode”).
HWhen setting, bear in mind that your heating system
requires some time to heat the rooms to the required
temperature.
HIn the extended menu, you can scan the current time
program under “Information” (see chapter “Scanning
information”, “Heating circuit ...” group).
Extended menu:
1.
2. “Heating”
3. Select the heating circuit if necessary.
4. “Heating time program”
5. Select part of the week or a day.
6. Select the time phase !,?, §or $.
7. Set the start and end points for the relevant time
phase.
8. Press to exit the menu.
Note: If you want to terminate a time phase setting
process prematurely, keep pressing until the
required display appears.
Example shown:
HTime program for Monday to Friday
(“Mo-Fr”)
HTime phase !:
From 05:00 to 08:30 h
HTime phase ?:
From 16:30 to 23:00 h
Deleting a time phase
Set the time for the end point to the same time that was
set for the start point. The display shows the selected
time phase ”- - : - -”.
Example:
You want to set the same time program for every day
except Monday:
Select the period “Monday–Sunday” and set the time
program.
Then select “Monday” and set the time program for this.

17
5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Central Heating
Changing the Heating Curve
Your system’s heating characteristics are affected by the
slope and the shift of the selected heating curve.
Further information about the heating curve can be found
under “Terminology” on page 40.
Factory setting:
HSlope: 1.4
HHeating curve shift: 0
HStandard room temperature (set value): 68° F (20° C)
HReduced room temperature (set value): 37° F (3° C)
Extended menu:
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Heating curve”
5. “Slope” or “Shift”
Note: Tips on when and how to change the heating
curve slope and shift are displayed by pressing
?
.
6. Set the required value.
Example:
Change the heating curve slope to 1.5.
A graph clearly shows the change in the heating curve
as soon as you alter the value for slope or shift.
Depending on various outside temperatures (shown on the
horizontal axis), the assigned set supply temperatures for
the heating circuit are highlighted white.
Stopping Central Heating
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Heating program”
5. “Only DHW” (summer mode, no central heating)
or
“Standby mode” (frost protection monitoring)

5793 310 - 02
18
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
Comfort and Energy Saving Functions
Selecting Comfort Function “Party Mode”
Make the settings for the comfort function at the
Vitotronic 300-K.
With this function, you can change the room temperature
for several hours, e.g. if guests unexpectedly stay longer
in the evening. You do not have to change any existing
control settings. With this function, DHW is reheated to
the selected set temperature.
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Party mode”
5. Set the room temperature required during party mode.
HThe rooms are heated to the required temperature.
HDHW is reheated to the selected set temperature.
HThe DHW circulation pump is switched ON (if installed).
Ending party mode
HAutomatically when the system switches to standard
heating mode in accordance with the time program.
or
HIn the extended menu, set “Party mode” to “OFF”.
Selecting Energy Saving Function “Economy Mode”
Make the settings for the energy saving function at the
Vitotronic 300-K.
To save energy, you can reduce the room temperature
in standard heating mode. For example, if you leave your
home for a few hours.
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Economy mode”
Ending economy mode
HAutomatically when the system switches to reduced
heating mode in accordance with the time program.
or
HIn the extended menu, set “Economy mode” to “OFF”.

19
5793 310 - 02
Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating Comfort and Energy Saving Functions
Selecting Energy Saving Function “Holiday Program”
The holiday program has the following effect on the
heating circuits and DHW heating:
HCentral heating:
- For heating circuits in the heating program “Heating
and DHW”:
In these heating circuits, the rooms are heated to the
selected reduced room temperature (see page 15).
- For heating circuits in the heating program “Only
DHW”:
No central heating in these heating circuits.
If the heating program “Only DHW” is selected for
all heating circuits, frost protection monitoring is only
enabled for the boiler and DHW tank.
HDHW heating:
DHW heating is switched OFF; frost protection for the
DHW tank is active.
To save energy, for example over long holidays, you can
activate the “Holiday program”.
Make the settings for this energy saving function at the
Vitotronic 300-K.
Note: The control unit is set up so that the holiday
program applies to all heating circuits. If you
want to make changes, contact your local heating
contractor.
The holiday program starts at 00:00 h the day following
your departure and ends at 00:00 h on the day of your
return. This means the selected time program is active
on the days of departure and return (see page 16).
Extended menu:
1.
2. “Heating”
3. “Holiday program”
4. Set the required departure and return dates.
Display in the extended menu
In the extended menu, you can scan the selected holiday
program under “Information” (see chapter “Scanning
information”, “Heating circuit ...” group).
Terminating or deleting a holiday program
Extended menu
1.
2. “Heating”
3. “Holiday program”
4. “Delete program”

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Vitotronic 100, GC1B / Vitotronic 300-K, MW1B Operating
DHW Heating
Required Settings (DHW Heating)
Note: The control unit is set up so that DHW heating
applies to all heating circuits. If you want to make
changes, contact your local heating contractor.
Setting the DHW Temperature
Setting the Heating Program for DHW Heating
Extended menu
1.
2. “Heating”
3. Select the heating circuit, if necessary (see page 14).
4. “Heating program”
5. “Heating and DHW” (with central heating)
or
“Only DHW” (summer mode, no central heating)
Extended menu
1.
2. “DHW”
3. “Set DHW temperature”
4. Set the required value.
Make the settings for DHW heating at the Vitotronic 300-K.
If you want DHW heating, check the following points:
HHave you set the required DHW temperature?
For settings, see the next chapter.
HHave you selected the correct heating program?
For settings, see below.
HHave you set the required time program?
For settings, see page 21.