Viessmann VITOCROSSAL 300 User manual

Operating Instructions
VITOCROSSAL 300
5790 737 - 01 03/2017
for use by heating contractor
Vitocrossal 300 CA3 Series 2.5, 3.0, 3.5, 4.0, 5.0 and 6.0
with Vitotronic 300 GW6C control
Gas condensing boiler with weather-compensated control unit
Read and save these instructions for
future reference.
Please file in Service Binder
Heating input: 2500 to 6000 MBH
(733 to 1758 kW)
Product may not be exactly as illustrated.
Do not store or use gasoline or other
flammable liquids in the vicinity of this
or any other appliance.
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliances.
Do not touch any electrical switches,
do not use any phone in your building.
Immediately call your gas supplier
from a neighbor’s phone. Follow
the gas supplier’s instructions.
If you cannot reach your gas supplier,
call the fire department.
Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.
WARNING
If the information in this manual is not followed
exactly, a fire or explosion may result causing
property damage, personal injury or loss of life.
WARNING
Improper installation, adjustment, and/
or operation could cause carbon monoxide
poisoning resulting in injury or loss of life.
This product must be installed and serviced
by a professional service technician who is
experienced and qualified in hot water boiler
installation and gas/oil combustion.
H
IMPORTANT

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5790 737 - 01
Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
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).
General Information
WARNING
Installers must follow local regulations with respect
to installation of carbon monoxide detectors. Follow
the Viessmann maintenance schedule of the boiler
contained in “Service Instructions”.
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”.
Contaminated air
Air contaminated by chemicals can cause by-products
in the combustion process, which are poisonous to
inhabitants and destructive to
Viessmann equipment.
For a listing of chemicals which
cannot be stored in or near the
boiler room, please see subsection
entitled “Mechanical Room”.
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.
Carbon monoxide
Improper installation, adjustment, service and/or
maintenance can cause flue products to flow into
living space. Flue products contain poisonous carbon
monoxide gas.
For information pertaining to the
proper installation, adjustment, service
and maintenance of this equipment to
avoid formation of carbon monoxide,
please see sections entitled
“Mechanical Room” and “Venting
Connection” in the Installation Instructions.
Fresh air
This equipment requires fresh air for
safe operation and must be installed
ensuring provisions for adequate
combustion and ventilation air exist.
For information pertaining to the
fresh air requirements of this product,
please see subsection entitled
“Mechanical Room”.
Equipment venting
Never operate boiler without an installed venting
system. An improper venting system can cause
carbon monoxide poisoning.
For information pertaining to
venting and chimney requirements,
please see section entitled “Venting
Connection”. All products of
combustion must be safely vented
to the outdoors.

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5790 737 - 01
Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
About these Instructions
Take note of all symbols and notations intended to draw attention to potential hazards or important product
information. These include “WARNING”, “CAUTION”, and “IMPORTANT”. See below.

IMPORTANT
Warnings draw your attention to the presence of
potential hazards or important product information.
Cautions draw your attention to the presence of
potential hazards or important product information.
Helpful hints for installation, operation or maintenance
which pertain to the product.
This symbol indicates that additional, pertinent
information is to be found.
This symbol indicates that other instructions must
be referenced.
General Information
WARNING
Indicates an imminently hazardous situation which,
if not avoided, could result in death, serious injury
or substantial product/property damage.
CAUTION
Indicates an imminently hazardous situation which,
if not avoided, may result in minor injury or product/
property damage.
Product Information
WARNING
Exposing the boiler to pressures and temperatures in
excess of those listed will result in damages, and will
render warranty null and void.
The Viessmann Vitocrossal 300, CA3 boiler series is CSA
certified for Canada, is constructed in compliance with
CSA B51 Standard and carries Canadian Registration
Numbers. The boiler is suitable for a maximum operating
pressure of 160 psig and a maximum boiler water
temperature of 210°F (99°C).
The Vitocrossal 300, CA3 boiler must only be installed
in closed loop hot water heating systems using a pre-
charged membrane expansion tank.

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5790 737 - 01
Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Table of Contents
Safety, Installation and Warranty Instructions ............... 2
About these Instructions ............................................ 3
Product Information ................................................... 3
For your Safety ......................................................... 6
Operation ................................................................. 6
Gas Smell............................................................. 6
Flue gas Smell ...................................................... 6
Dangerous conditions ............................................ 6
Working on the Equipment ..................................... 6
Combustion air and ventilation openings................... 6
Carbon monoxide .................................................. 6
Frozen water pipe hazard ....................................... 7
Boiler room conditions ........................................... 7
Maintenance and cleaning ...................................... 8
Regular maintenance and service............................. 8
Technical information ............................................ 8
Description............................................................... 9
Fuel....................................................................10
Boiler control .......................................................10
Condensate disposal .............................................10
Boiler location ......................................................10
Venting connection ..............................................10
Optimum operation...............................................10
Operation ................................................................11
Starting the heating system ...................................11
Separate heating system controls ...........................11
Domestic hot water production ..............................11
System shutdown ................................................11
Commissioning ................................................... 12
Your System is Preset at the Factory ..........................12
Energy Saving Tips...................................................13
Tips for Greater Comfort...........................................13
General Boiler Information .........................................14
System and Lead Control Boiler Section 1
Programming Unit ....................................................15
Service Display Lag Boiler Sections ............................16
Starting the Heating System....................................17
Shutting Down the Heating System ............................18
Operating Program ...................................................18
General Information
Safety
System Information
Operation
Page

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating Table of Contents
Central Heating
DHW Heating
Further Adjustments
Scanning
Scanning Options
Emissions
Troubleshooting
Maintenance
Additional Information
Page
Time Program ..........................................................19
Room Temperature ...................................................21
Operating Program ...................................................22
Time Program ..........................................................22
Heating Curve..........................................................23
Stopping Central Heating ..........................................23
Comfort Function.....................................................24
Energy Saving Function “Economy Mode”...................25
Energy Saving Function “Holiday Program”..................26
DHW Temperature....................................................27
Operating Program ...................................................27
Time Program ..........................................................27
Setting the Display Backlighting .................................29
Naming Heating Circuits............................................29
Setting the Time and Date ........................................29
Language Selection ..................................................30
Setting the Measuring Units.......................................30
Restoring Factory Settings.........................................30
Scanning Information................................................31
Main Menu Overview................................................34
Scanning Options under “Information” ........................36
Emissions Test Mode................................................37
Rooms are Too Cold ................................................38
Rooms are Too Hot ..................................................39
There is No DHW ....................................................39
The DHW is Too Hot ................................................40
“Fault” will be Displayed ...........................................40
“Service” will be Displayed ........................................40
Inspection and Maintenance ......................................41
Service Schedule......................................................41
Additional Maintenance Information............................42
Terminology ............................................................42

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
For your Safety
Working 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 have been deactivated. Close main
gas supply valve. Take precautions in all instances to
avoid accidental activation of power during service
work.
Combustion air and ventilation openings
Ensure that combustion air openings and ventilation
air openings in the mechanical room are open.
Carbon monoxide
The U.S. Consumer Product Safety Commission
strongly recommends the installation of carbon
monoxide detectors in buildings in which gas-burning
equipment is installed. Carbon monoxide (CO) is a
colorless, odorless gas, which may be produced during
incomplete combustion of fuel and/or when the flame
does not receive an adequate supply of combustion air.
Carbon monoxide can cause severe personal injury or
loss of life.
Therefore, carbon monoxide detectors that are in
compliance with a nationally recognized latest standard
(e.g. ANSI/UL 2034, CSA 6.19-01) should be installed
and maintained in buildings that contain gas-burning
equipment.
Note: Viessmann does not test any detectors and
makes no representation regarding any brand
or type of detector.
Incomplete combustion and poisonous gases result if the
fresh air intakes in the mechanical room are closed. Never
close these openings.
CAUTION
Operation
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.
Gas smell
Follow the instructions on the front of the manual.
Flue gas smell
- Deactivate heating equipment.
- Open windows and doors.
- Inform your heating contractor immediately.
Dangerous conditions
- Deactivate main power immediately
- Close gas supply valve
CAUTION
Follow these safety instructions closely to avoid the risk
of injury and damage to property.
In emergencies
Immediately switch off the power supply, e.g. at the
separate fuse or power supply disconnect switch
(unless there is a smell of gas).
Close the shut-off valves in the oil pipes or close the
gas shut-off valve, whichever applicable.
Use suitable extinguishers in the event of fire.
Safety

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating Safety
For your Safety (continued)
WARNING
The boiler must not be located in areas or rooms
where chemicals are stored, or aggressive vapors
from (i.e. bleach, hair spray, methyl chloride, carbon
tetrachloride or perchloroethylene) or high dust levels
or humidity levels are present. Heat exchanger
corrosion might occur and reduce the lifetime of the
boiler significantly. If above criteria are not properly
observed and boiler damage results, any warranty on
the complete boiler and related components will be
null and void.
IMPORTANT
Keep boiler and boiler room clear and free from combustible
materials, gasoline and other flammable vapors and liquids.
Do not obstruct the flow of combustion and ventilation air.
All inspection, maintenance and service must be performed
by a qualified heating contractor.
Boiler room conditions
- Do 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)
- Do not use a room subject to high levels of dust
- Do not use a room subject to permanently high humidity
- The room should be frost-protected
- Max. ambient temperature 95°F (35°C).
- Provide good ventilation and do not close or obstruct vents
(if installed).
Frozen water pipe hazard
Your heating boiler is designed to provide a warm and
comfortable living environment. It is NOT designed to
ensure against freezing of water pipes.
The boiler is equipped with several safety devices that are
designed to shut down the boiler and to prevent it from
restarting in the event of various unsafe conditions.
If your boiler remains off for an extended period of time
during cold weather, water pipes may freeze and burst,
resulting in extensive water damage and conditions in
which mold could grow. Certain molds are known to
cause respiratory problems, as well as to pose other
serious health risks. In case of water damage, immediate
measures should be taken to dry out affected areas as
quickly as possible to prevent mold from developing.
If your home will be unattended for an extended period
of time during cold weather, you should...
- Shut off the water supply to the building, drain the
water pipes and add an antifreeze for potable water
to drain traps and toilet tanks. Open faucets where
appropriate.
or...
- Have someone check the building frequently during
cold weather and call a qualified service agency if
required.
or...
- Install a reliable remote temperature sensor that will
notify somebody of freezing conditions within the
home.
WARNING
Failure to protect against frozen pipes could result in
burst water pipes, serious property damage and/or
personal injury. Boiler may shut down. Do not leave
your home unattended for long periods of time during
freezing weather conditions without turning off the
water supply and draining water pipes or otherwise
protecting against the risk of frozen pipes.
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.

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5790 737 - 01
Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
WARNING
Improper installation, adjustment, service, or
maintenance can cause flue products to flow into
living space. Flue products contain poisonous carbon
monoxide gas which can cause nausea or asphyxiation
resulting in severe personal injury or loss of life.
WARNING
As there are no user-serviceable parts on the boiler,
burners or control, the end-user must not perform
service activities of any kind on system components.
Failure to heed this warning can cause property
damage, severe personal injury, or loss of life.
WARNING
Do not use this boiler if any part has been under or
exposed to water. Immediately call a qualified heating
contractor to inspect the boiler and to replace any part
of the control system and any gas control which has
been under, or exposed to, water.
Maintenance and cleaning
Regular inspection and service by a qualified heating
contractor is important to the performance of the
Viessmann Vitocrossal 300, CA3 boilers. Neglected
maintenance impacts on warranty; regular inspection
ensures clean, environmentally friendly and efficient
operation. We recommend a maintenance contract
with a qualified heating contractor.
Regular maintenance and service
The entire heating system must be cleaned and
serviced on a regular basis by a qualified heating
contractor or service agency to ensure reliable,
energy-efficient, and environmentally friendly
operation.
The build-up of soot on the heat exchanger raises
the flue gas temperature and reduces efficiency.
Indirect-fired domestic hot water storage tanks (if
installed) should be serviced within two years (at
most) of the installation date, and regularly thereafter.
For an overview of scheduled service procedures,
please see section entitled “Service Schedule” on
page 42 of this manual.
The owner or dedicated personnel should perform
the checks outlined in the Service Schedule to ensure
proper operation of the heating system.
IMPORTANT
Technical information
Literature applicable to the Vitocrossal 300, CA3 boiler:
- Installation and Service Instructions
- Operating Instructions
Keep all literature in a safe place at the installation site.
Contact Viessmann for additional copies.
For your Safety (continued)
Safety

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Description
System Information
Legend
SA Safety header
KV Boiler supply
LG Natural gas connection
KR Boiler return
AGA Flue gas outlet (vent pipe connection)
CA3 2.5, 3.0, 3.5 and 4.0
CA3 5.0 and 6.0
Dimensions
Boiler Model 2.5 and 3.0 3.5 and 4.0 5.0 and 6.0
L in. (mm) 6 (152) 6 (152) 6 (152)
M*1 in. (mm) 11c(299) 11c(299) 11c(299)
N in. (mm) 35 (889) 40 (1015) 44 (1118)
O in. (mm) 28e(720) 32a(820) 32a(820)
P*1 in. (mm) 14 (357) 14 (357) 14 (357)
Dimensions
Boiler Model 2.5 and 3.0 3.5 and 4.0 5.0 and 6.0
A in. (mm) 90c(2305) 101f(2581) 138 (3503)
B in. (mm) 33b(851) 39e(1000) 39e(1000)
C*1 in. (mm) 78 (1981) 84 (2131) 84 (2131)
D in. (mm) 85e(2168) 96f(2453) 133 (3376)
E in. (mm) 31b(800) 36 (936) 36 (936)
F*1 in. (mm) 73 (1875) 78 (2002) 78 (2002)
G*1 in. (mm) 69e(1760) 74e(1887) 74e(1887)
H*1 in. (mm) 62 (1574) 64d(1628) 64d(1628)
I*1 in. (mm) 26a(667) 26a(665) 26a(665)
J in. (mm) 12 (325) 9c(248) 9c(248)
K in. (mm) 71e(1813) 79a(2013) 111d(2823)
*1 Heights do not include the concrete pad or seismic brackets.
Seismic brackets will add 2einches (60 mm).
Seismic brackets are only for boiler models 3.5 to 6.0.

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
System Information
Description (continued)
Fuel
Natural gas (NG) or liquid propane gas (LPG).
Boiler control
The Vitocrossal 300, CA3 boiler series is operated with
a Vitotronic control and microcomputer indoor/outdoor
control system for boiler operation without low temperature
limit. The control system must be programmed for this type
of operation by the installing heating contractor.
Refer to the boiler Installation and Service
Instructions.
CAUTION
The boiler room must be safe from frost and be
properly ventilated.
Condensate disposal
During the operation of the Vitocrossal 300 CA3 boiler,
the amount of condensate as per the diagram can be
expected.
The values given are approximate amounts occurring under
practical conditions. Not included in the chart is the amount
of condensate occurring in the vent pipe and chimney
system. The condensate from the chimney system can be
collected together with the condensate from the heating
boiler and be disposed of into a floor drain.
The condensate occurring will have a pH value between
3 and 4. If local building requirements demand neutralizing
the condensate before disposal, contact Viessmann
Manufacturing Company Inc. for a correctly sized
neutralization tank. The treated condensate will show pH
values of between 6.5 and 9 and can then be disposed of
into the waste water system.
Boiler location
The boiler must not be installed in rooms or areas where
halogenated hydrocarbons are present in the combustion
air, such as barber shops and beauty salons, printing
shops, chemical cleaners, laboratories etc.
Vitocrossal 300, CA3 boiler efficiency is dependent
on system heating water return temperatures and load
conditions.
Venting connection
A large amount of water vapor is contained in the flue
gases of a condensing boiler. The condensate pH value is
between 3 and 5.5. The flue gas temperatures depending
on the boiler water temperature may be between 77°F
(25°C) and 257°F (125°C).
The manufacturer of the chimney system or venting
system has to properly design the venting system as well
as select proper materials.
If there are any questions in regards to the neutralization
of the condensate and/or to the venting of this boiler
series, contact your local Viessmann Sales Representative.
Optimum operation
To ensure optimum operation of your heating system do
the following:
Keep the boiler and the boiler room clean and free
of dust and dirt.
Ensure proper and adequate system pressure by
occasionally checking the pressure gage.
Have a qualified heating contractor service and
maintain your heating system on a regular basis.
See Service Schedule starting on page 42 for details.
Amount of condensate
Boiler water return temperature
Flue gas temperature gross
Flue gas temp.
at full input
at partial load
Flue gas temp.
Amount of
condensate

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating System Information
Operation
System shutdown
The boiler controls monitor the operation of your heating
system in conjunction with installed system controls (if
applicable) based upon indoor/outdoor control, setback
programming and other settings. Please refer to the
respective documentation of the boiler controls, or other
system controls, to make adjustments.
Deactivate main power switch and all additional switches
controlling additional pumps or controls, including main
switch for burners. Close all valves in the system.
Read the operating instructions supplied with the Vitotronic
control, as well as Operating Instructions of the gas
burners before deactivating or activating the heating
system.
IMPORTANT
Separate heating system controls
In case additional controls are installed in the boiler room,
e.g. control aquastats, mixing valves, controls etc.,
please observe their respective operating instructions.
Domestic hot water production
The Vitocrossal 300, CA3 boiler may be used to supply
domestic hot water heating by means of an indirect-fired
hot water storage tank. The appropriate connections
to the boiler must be made, as well as the correct size
circulating pump must be used. The control circuit to
provide domestic hot water is already provided within
the Vitotronic control.
Starting the heating system
Ask your heating contractor about the following:
Boiler and relevant control unit type
Level of the required system pressure
Position of the pressure gauge, shutoff valve,
gas shut-off valve, ventilation apertures
1. Check the heating system pressure at the pressure
gauge. If the pressure of the heating system is too
low, top up the water or notify your heating
contractor.
2. 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 the ON/OFF switch ON (see diagram).
After a short time, the home screen is displayed
and the green ON indicator illuminates.
Your heating system and, if installed, your remote
controls are now ready for use.
Legend
AON/OFF switch
BON indicator (green)
CFault indicator (red)

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Commissioning
System Information
As the user of new combustion equipment, you may be
obliged to notify your local service technician of the
installation [check local regulations]. 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 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 the heating contractor.
Your System is Preset at the Factory
The Vitotronic 300 GW6C control comes shipped with
factory default settings that ensure secure operation
and provides basic operating functions. Upon powering
up the Vitocrossal 300, CA3 boiler and burners may
be initially commissioned or temporarily operated with
the factory default values. It is recommended that the
commissioning process is completed with either the
‘Commissioning Assistant’ (refer to the installation/service
instructions on ‘Commissioning the System’) or through
‘System Configuration’ in the service menu (refer to the
installation/service instructions on ‘calling up the service
menu’).
Your heating system is preset at the factory and is
therefore ready for operation:
Central heating
HBetween 12:00 am and 12:00 am (00:00 h and 24:00 h),
the rooms are heated to 68°F (20°C) “Room temp set
point” (standard room temperature).
DHW heating
HBetween 12:00 am and 12:00 am (00:00 h and 24:00 h)
DHW will be heated to 122°F (50°C) “DHW
temperature setpoint”.
Any installed DHW recirculation pump is switched on.
Frost protection
HYour boiler and DHW tank are protected against frost.
Daylight savings time
HThis changeover is automatic.
Date and time
HThe date and time were set by your heating contractor.
You can change these settings at any time to suit your
individual requirements.
Power failure
All settings are saved if there is a power failure.

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating System Information
HHoliday:
If you are going away, select the “Holiday program”:
The room temperature will be reduced, and DHW
heating will be turned off.
HVentilation:
Close the thermostatic valves when ventilating.
Open the windows fully for a brief time.
HRoller shutters:
Close roller shutters (if installed) at dusk.
HThermostatic valves:
Ensure that thermostatic valves are properly adjusted.
HRadiators:
Never cover radiators or thermostatic valves.
DHW heating
HDHW recirculation pump:
Only activate the DHW recirculation pump for periods
in which DHW is regularly drawn off. Set the time
program for this.
HDHW consumption:
Consider showering instead of running a bath. A
shower generally uses less energy than a full bath.
For additional energy saving functions of the Vitotronic
control unit, please contact your heating contractor.
Central heating
HStandard room temperature
(“Room temp target”):
Never overheat your home. Every degree of room
temperature reduction saves up to 6% on your heating
bills. Never set your standard room temperature higher
than 68°F (20°C).
HTime program:
Heat your home to the standard room temperature
during the day and the reduced temperature at night.
Set the time program for this.
HOperating program:
If you do not require central heating, select one of the
following operating programs:
– “DHW only”:
If you require no heating for your home in summer,
but you need hot water.
– “Standby mode”:
If you don’t need to heat your home and don’t need
hot water for long periods.
HShort absence:
Reduce the room temperature if you are going out
shopping, for example. For this, select “Economy
mode”.
Tips for Greater Comfort
Central heating
HStandard room temperature
(“Room temp set point”):
You can select your individual preferred temperature
at any time in the standard menu.
HTime program:
Make use of the time program. In the time program,
you can set time phases with different room
temperatures, for example different temperatures for
day and night time.
HHeating curve:
The heating curve enables you to individually adjust
the heating system to the actual heat demand in your
home.
If set correctly, your preferred temperature will be
achieved all year round.
H“Comfort mode”:
Select “Comfort mode” if you want to heat your
interior at a temperature that deviates from that
in a time program.
Example: Late in the evening, the reduced room
temperature is set by the time program.
Your guests stay longer.
DHW heating
HTime program:
Make use of the time program.
Energy Saving Tips

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Operation
General Boiler Information
Multi boiler application
In a multi boiler application there can be a minimum of
4 boiler sections (e.g. two model 3.5 boilers) and a
maximum of 8 boiler sections (e.g. one model 4.0 and
two model 6.0 boilers).
For the 2nd boiler, Awould be the next lag control in
sequence (e.g. if the 1st boiler ended with Clag 2 control,
section 3, then the 2nd boiler would start with lag 3 control,
boiler section 4 and will continue in sequence for this boiler
and the next.
All boiler sections are controlled and displayed through the
first boiler Alead control boiler section 1. For the 2nd
(3rd or 4th) boiler the lower front panel and control cover
are required to be opened to set up for the lag control.
Service and Emissions
For all CA3 boilers Band Care used for lag boiler
section service displays. For the 2nd (3rd or 4th) boiler
Ais used as a lag boiler section service display.
To respond to a service condition for Band Cthe
lower front boiler panel and control cover are required to
be opened. To respond to a service condition for Athe
top front boiler panel and control cover may or may not be
opened depending on the fault condition.
For all boilers the front boiler top and bottom panels and
control covers must be opened to access the emissions
test switch D, E and F.
Single boiler application
Each Vitocrossal 300 CA3 boiler section is equipped with
it’s own control unit. The CA3 models 2.5 and 4.0 each
have two boiler sections and the CA3 models 5.0 and 6.0
each have three boiler sections.
For all CA3 single boiler applications Ais the system and
lead control section 1 and Bis the lag 1 control, boiler
section 2. For models CA3 5.0 and 6.0 Cis the lag 2
control, boiler section 3.
No front panels or control covers are required to be opened
to set up the controls for a single boiler application.
Boiler model 2.5 and 3.0
Boiler model 3.5 to 6.0

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
A screensaver appears if there has not been any operation
for some time:
The programming unit is equipped with a touchscreen.
To make settings and call up information, press the
on-screen buttons.
Default display
In the default display, the number of boiler sections in-
stalled in the heating system is shown in a specific
order (boiler section sequence).
Call up the default display as follows:
If the screensaver is active:
Tap anywhere on the screen.
You are now in the main menu (see page 34).
Press .
You can change any settings on your heating system
centrally at the programming unit of the system and lead
control boiler section 1.
If remote control units are installed in your rooms, you
can also adjust the settings at the remote control units.
Remote control operating instructions
System and Lead Control Boiler Section 1 Programming Unit
Operation
Boiler section operating mode
The depiction of the flame represents the current boiler
section heating output:
Flame at glength 1 to 33%
Flame at hlength 34 to 66%
Flame at full length 66 to 100%
Depiction of a circle, see E:
Solid white:
The boiler section has been enabled by the system and
lead control unit and is operational, boiler section 1 in
this example.
Solid grey:
The boiler section 2 is available for generating heat but has
not been called for by the system and lead control unit
(boiler section 2 in this example).
Criss-crossed:
The boiler section is unavailable for generating heat,
boiler section 3 in the example shown.
The value below the circle indicates the current output.
Main menu
In the main menu, you can make all settings across the
range of functions available at the system and lead control
unit as well as scan details, such as the heating defaults
and set time programs. See menu overview on page 34.
Call up the main menu as follows:
If the screensaver is active:
Tap anywhere on the display and then on .
From anywhere in the menu:
Tap and then tap “Menu”.
Footer buttons
Returns you to the home screen.
Takes you to the previous step in the menu or
cancels a setting that has been started.
Calls up the help text.
Calls up fault or service messages.
Scrolling through the menu.
The screensaver appears after a while when no input
has been made.
Legend
AHeader
BActual common supply temperature (boiler)
CSet common supply temperature (boiler)
DBoiler section number in the sequence
EDetails of the boiler section operating status
(see the following chapter)
FFooter
Legend
AHeader
FFooter

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Operation
A screensaver appears after opening the control unit,
or if there has not been any operation for some time:
Each service display unit is equipped with a touchscreen.
To make adjustments and scan information, tap the
on-screen buttons.
Home screen
Call up the home screen as follows:
HScreensaver is active:
Tap the display anywhere.
HFrom anywhere in the menu tap .
Boiler section operating mode
The flame symbol indicates the current boiler heating
output:
HFlame with glength 1 to 33%
HFlame with hlength 34 to 66%
HFlame with full length 67 to 100%
Circle symbol:
HSolid white:
The boiler section has been enabled by the system and
lead control unit and is operating.
HSolid grey:
The boiler section is available for generating heat but
has not been called for by the system and lead control
unit.
HCrisscrossed:
The boiler section is not available for generating heat.
Legend
AHeader
BActual boiler section water temperature
CSet boiler section water temperature
DBoiler section number
EDetails on the boiler section operating mode
(see the following chapter)
FFooter
Footer buttons:
Returns you to the home screen.
Takes you back one menu level or cancels
a setting that has been started.
Calls up the help text.
Calls up fault or service messages.
Scrolls through the menu.
Legend
AHeader
FFooter
Main menu
You can make scans and settings in the main menu.
You can find the menu overview on page 34.
Call up the main menu as follows:
HScreensaver is active:
Tap the display anywhere and then tap“Menu”.
HFrom anywhere in the menu:
Tap and then tap “Menu”.
Service Display Lag Boiler Sections

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Starting the Heating System
Operation
1. Check the heating system pressure at the pressure
gauge. If the pressure of the heating system is too low,
top up the water or notify your heating contractor.
2. Open the gas shut-off valve on every boiler.
3. Switch ON the power supply, e.g. at a separate MCB/
fuse or a mains isolator.
Legend
AON/OFF switch
BON indicator (green)
CFault indicator (red)
Ask your heating contractor about the following:
HBoiler and relevant control unit type
HLevel of the required system pressure
HPosition of the following components:
– Temperature/pressure gauge
– Gas shut-off valve
– Air vent
Note: The ON/OFF switches of the lag boiler sections
must be switched ON during system commissioning.

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Shutting Down the Heating System
IMPORTANT
With frost protection monitoring
For every heating circuit select the “Standby mode”
operating program
HNo central heating
HNo DHW heating
HFrost protection for the boiler and the DHW tank
is active.
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.
If outdoor temperatures of below 37°F (3°C) are expected,
take appropriate measures to protect the heating system
from frost.
If necessary, contact your heating contractor.
Information on a prolonged shutdown
HCirculation pumps may seize up as they are not being
supplied with power.
HIt may be necessary to reset the date and time
(see page 24).
Symbol Operating program Function
w
r
“Heating and DHW” HThe rooms of the
selected heating
circuit are heated in
accordance with the
room temperature and
time program specified
(see chapter “Central
heating”).
HDHW is heated in
accordance with the
DHW temperature and
time program specified
(see chapter “DHW
heating”).
w“DHW only” HDHW is heated in
accordance with the
DHW temperature and
time program specified
(see chapter “DHW
heating”).
HNo central heating
HFrost protection for
the boiler and the
DHW tank is active.
9“Standby mode” HNo central heating
HNo DHW heating
HFrost protection for
the boiler and the DHW
tank is active.
Special operating programs
H“External hook-up”
The operating program set at the system and lead
control unit was changed by an external device,
e.g. EA1 extension.
H“External program”
The operating program set at the control unit was
changed over by the Vitocom communication interface.
H“Holiday program”
See page 21.
Note: In the main menu, you can scan the set operating
program under “Information”.
Operating programs for central heating, DHW, frost protection
Without frost protection monitoring (shutdown)
1. Switch OFF the ON/OFF switch on every system and
lead control unit (see page 17).
2. Close the gas shut-off valves.
3. Isolate the heating system from its main power supply,
e.g. at the separate MCB/fuse or at a mains isolator.
Operating Program
Operation

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Time programs are set at the system and lead boiler
section control. The following explains how to input
the settings for a time program. The special features
of individual time programs are allotted to the relevant
chapters.
You can set up a time program for the following functions:
HCentral heating
HDHW heating
HDHW recirculation pump
The time program allows you to divide the day into time
blocks. These are called time phases. It is for you to
decide what happens in these time phases, e.g. whether
your rooms should be heated to the standard room tem-
perature.
HYou can set the time program individually, to be the
same, or different, for every day of the week.
HYou can select up to 4 time phases per day.
HFor each time phase you select the start and end points.
HIn the main menu, you can scan the time programs
under “Information” (see from page 34).
Setting time phases
Example
HTime program for “Monday”
HTime phase 1: 05:30 am to 09:00 am (05:30 h to 09:00 h)
HTime phase 2: 4:30 pm to 10:00 pm (16:30 h to 22:00 h)
In between these time phases the system heats
to a reduced temperature.
From the home screen tap the following buttons:
1. “Menu”
2. “Heating”
3. “Heating circuit 1”
4. “Time program heating”
5. “Mo”
6. “Edit
7. for the start and end point of time phase 1.
The bar in the time diagram is adjusted.
Cancelling the setting of a time phase early Tap .
8. for time phase 2
9. for the start and end point of time phase 2.
The bar in the time diagram is adjusted.
10.Tap OK to confirm
11.
Note: The settings described in the following, using room
heating Heating circuit 1 as an example, also apply
to DHW heating and the DHW recirculation pump.
Time Program
Factory set condition
Time phase 1:
12:00 a.m. to 12:00 a.m. (00:00 h to 24:00 h)
Central Heating

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Vitocrossal 300 CA3 Series 2.5 to 6.0 Operating
Time Program (continued)
Transferring the time program to other days of the week
You can copy this time program for any other days of
the week.
You want to copy this time program for Monday to the
period Tuesday to Friday.
Tap the following on-screen buttons:
1. “Menu”
2. “Heating”
3. Heating circuit 1
4. “Time program heating”
5. “Mo”
6. “Copy”
7. “Tu” , “We”, “Th”, “Fr”
8. Press OK to confirm
9.
Central Heating
Changing time phases
For Tuesday you want to change the start point of time
phase 2 to 2:30 pm (14:30 h).
From the home screen tap the following buttons:
1. “Menu”
2. “Heating”
3. “Heating circuit 1”
4. “Time program heating”
5. “Tu”
6. “Edit”
7. for time phase 2
8. for the start point of time phase 2.
The bar in the time diagram is adjusted.
9. Tap OK to confirm
10.
Deleting time phases
For Wednesday you want to delete time phase 2.
From the home screen tap the following buttons:
1. “Menu”
2. “Heating”
3. “Heating circuit 1”
4. “Time program heating”
5. “We”
6. “Edit”
7. Select time phase 2
8. “x”
9. Tap OK to confirm
10.