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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5790 737 - 01
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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5790 737 - 01
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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5790 737 - 01
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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5790 737 - 01
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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5790 737 - 01
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