Viessmann Vitocrossal 200 CM2 246 User manual

Operating Instructions
VITOCROSSAL 200
5546 488 - 02 01/2023
for use by heating contractor
Vitocrossal 200
CM2 Series 186, 246, 311, 400, 500, 620 and 620 TX
Gas condensing boiler with cylinder burner
Read and save these instructions for
future reference.
Please file in Service Binder
Heating input: 663 to 2245 MBH
194 to 658 kW
Product may not be exactly as illustrated.
Do not store or use gasoline or other
ammable liquids in the vicinity of this
or any other appliance.
WHAT TO DO IF YOU SMELL GAS
g Do not try to light any appliances.
g Do not touch any electrical switches,
do not use any phone in your building.
g Immediately call your gas supplier
from a neighbor’s phone. Follow
the gas supplier’s instructions.
g If you cannot reach your gas supplier,
call the re department.
Installation and service must be
performed by a qualied 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

2
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 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”.
gProduct 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.
uFor a listing of applicable literature,
please see section entitled “Important
Regulatory and Safety Requirements”.
gWarranty
Information contained in this and
related product documentation must
be read and followed. Failure to do
so renders the warranty null and void.
gLicensed professional heating contractor
The installation, adjustment, service and maintenance
of this equipment must be performed by a licensed
professional heating contractor.
uPlease see section entitled
“Important Regulatory and Installation
Requirements”.
gContaminated air
Air contaminated by chemicals can cause by-products
in the combustion process, which are poisonous to
inhabitants and destructive to
Viessmann equipment.
uFor a listing of chemicals which
cannot be stored in or near the
boiler room, please see subsection
entitled “Mechanical Room”.
gAdvice 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.
gCarbon monoxide
Improper installation, adjustment, service and/or
maintenance can cause flue products to flow into
living space. Flue products contain poisonous carbon
monoxide gas.
uFor 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.
gFresh air
This equipment requires fresh air for
safe operation and must be installed
ensuring provisions for adequate
combustion and ventilation air exist.
uFor information pertaining to the
fresh air requirements of this product,
please see subsection entitled
“Mechanical Room”.
gEquipment venting
Never operate boiler without an installed venting
system. An improper venting system can cause
carbon monoxide poisoning.
uFor information pertaining to
venting and chimney requirements,
please see section entitled “Venting
Connection”. All products of
combustion must be safely vented
to the outdoors.

3
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating Table of Contents
Safety, Installation and Warranty Instructions................2
About these Instructions.............................................4
For your Safety..........................................................4
Operation...............................................................4
Gas smell...............................................................4
Flue gas smell.........................................................4
Working on the equipment.......................................5
Combustion air and ventilation openings....................5
Carbon monoxide....................................................5
Dangerous conditions..............................................5
Frozen water pipe hazard.........................................5
Maintenance and cleaning........................................6
Regular maintenance and service..............................6
Technical Information..............................................6
Description................................................................7
Fuel(s)...................................................................8
Boiler control..........................................................8
Condensate disposal................................................8
Boiler location.........................................................8
Venting connection.................................................8
Optimum operation..................................................8
Operation..................................................................9
Starting the heating system......................................9
Separate heating system controls.............................9
Domestic hot water production.................................9
System shutdown...................................................9
Service Schedule......................................................10
Additional Maintenance Information............................11
Danger of freezing.................................................11
Long periods of shutdown......................................11
Water quality........................................................11
General Information
Safety
System Information
Service and Maintenance
Page

4
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 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.
u
IMPORTANT
CAUTION
uWarnings draw your attention to the presence of
potential hazards or important product information.
uCautions draw your attention to the presence of
potential hazards or important product information.
uHelpful hints for installation, operation or maintenance
which pertain to the product.
uThis symbol indicates that additional, pertinent
information is to be found.
uThis symbol indicates that other instructions must
be referenced.
General Information/Safety
Incomplete combustion and poisonous gases result if the
fresh air intakes in the mechanical room are closed. Never
close these openings.
CAUTION
WARNING
Indicates an imminently hazardous situation which,
if not avoided, could result in death, serious injury
or substantial product/property damage.
Indicates an imminently hazardous situation which,
if not avoided, may result in minor injury or product/
property damage.
For your Safety
gOperation
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.
gGas smell
Follow the instructions on the front of the manual.
gFlue gas smell
- Deactivate heating equipment.
- Open windows and doors.
- Inform your heating contractor immediately.

5
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating Safety
For your Safety (continued)
gWorking 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.
gCombustion air and ventilation openings
Ensure that combustion air openings and ventilation
air openings in the mechanical room are open.
gCarbon 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 standard
(e.g. ANSI/UL 2034-2002, 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.
gDangerous conditions
- Deactivate main power immediately
- Close gas supply valve
gFrozen 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.
IMPORTANT
Keep all literature in a safe place at the installation site.
Contact Viessmann for additional copies.
WARNING
This product burns gas to produce heat. The appliance
must be properly installed, operated and maintained
to avoid exposure to appreciable levels of carbon
monoxide and the installer is required to confirm that
at least one carbon monoxide alarm is installed in the
living space before the appliance is put into operation.
It is important for the carbon monoxide alarms to be
installed, maintained, and replaced following the alarm
manufacturer’s instructions and applicable local codes.

6
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating
For your Safety (continued)
Safety
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.
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.
gMaintenance and cleaning
Regular inspection and service by a qualified heating
contractor is important to the performance of the
Viessmann CM2 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.
gRegular 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 10 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
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.
IMPORTANT
gTechnical information
Literature applicable to the Vitocrossal 200, CM2 boiler:
- Installation Instructions
- Service Instructions
- Operating Instructions
- Combustion air intake adaptor Installation Instructions
Keep all literature in a safe place at the installation site.
Contact Viessmann for additional copies.
CAUTION
Should overheating occur or the gas supply fail to
shut off, do not disconnect the electrical supply to the
pump. Instead, shut off the gas supply at a location
external to the appliance.

7
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating
Description
System Information
The Viessmann Vitocrossal 200, CM2 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 75 psig and a maximum boiler water temperature of
210°F (99°C).
The Vitocrossal 200 boiler must only be installed in closed
loop hot water heating systems using a pre-charged
membrane expansion tank.
Legend
V Vent pipe connection
D Drain
CD Condensate drain
BR Boiler return
BTS Boiler water temperature sensor
BS Boiler supply
SH Female connection NPT ½ in. for pressure gauge
CA Combustion air pipe connection
SS Safety supply; pressure relief valve, air vent,
low water cut-off
BO Boiler Inspection Opening
KTS Flue gas temperature sensor
The proper burner size must be verified and the burner
must be adjusted so that the maximum input of the
appropriate boiler size is always observed and adjusted.
The gas burner must be installed according to the
instructions supplied by the burner manufacturer.

8
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating
Description (continued)
System Information
Fuel(s)
Natural gas or liquid propane gas.
Boiler control
The Vitocrossal 200 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 installer.
Control instructions supplied with boiler control.
CAUTION
The boiler room must be safe from frost and be
properly ventilated.
Condensate disposal
During the operation of the Vitocrossal 200 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 200 boiler efficiency dependent on system
heating water return temperatures and load conditions
Venting connection
A large amount of water vapor contained in the flue gases
of condensing boilers condenses. 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:
gKeep the boiler and the boiler room clean and free
of dust and dirt.
gEnsure proper and adequate system pressure by
occasionally checking the pressure gage.
gHave a qualified heating contractor service and
maintain your heating system on a regular basis.
See Service Schedule starting on page 10 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

9
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating System Information
Operation
System shut-down
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 burner. Close all valves in the system.
Read the operating instructions supplied with the Vitotronic
control, as well as Operating Instructions of the gas burner
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 200 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.
AON indicator (green)
BFault indicator (red)
CEmissions test switch (only for service purposes)
DON/OFF switch
EMCB/fuses
Starting the heating system
Ask your heating contractor about the following:
gBoiler and relevant control unit type
gLevel of the required system pressure
gPosition 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 standard menu is displayed
and the green ON indicator illuminates.
Your heating system and, if installed, your remote
controls are now ready for use.

10
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating
Service Schedule
Service and Maintenance
Frequency Performed by 4Service
Monthly Owner /
Operator
Check the system pressure frequently.
Ensure proper operation of the boiler control.
Inspect all seals; retighten or replace as necessary.
Ensure an adequate supply of combustion air/ventilation air into and out of
the mechanical room is maintained.
Ensure that nothing obstructs the flow of combustion - ventilation air, and no
chemicals, garbage, gasoline, combustible materials, flammable vapors, or liquids
are stored, not even temporarily, in the vicinity of the boiler.
Check for water on the floor from the discharge pipe of pressure relief valve
or any other pipe, pipe joint, valve, or air vent.
Test pressure relief valve and check for proper operation.
Check all operational high limits for proper operation.
Check for proper operation of the condensate neutralization system (if used).
Test pressure relief valve and check function.
Check the condition and fill status of the neutralization media.
Check the pH value of the flue gas condensate.
Check for moisture/water on vent pipe joints and appearance of ice on the vent
pipe or chimney outlet in the winter time.
Annually Owner /
Operator
Ensure service work/test is conducted at least annually by a qualified heating
contractor, and that any deficiencies are corrected immediately.
Heating
Contractor
Test functionality of safety high limits.
Test burner with burner accessories according to the corresponding maintenance
checklist.
Test and establish proper chemical makeup of system water.
Check flue pipe condition, chimney connection and chimney itself.
Check pressure relief valve and system pressure, and verify proper operation.
Check heating pipe joints, valves, air vents, etc. System leaks must be corrected
immediately to avoid further defects. The cause of defect must also be determined
in order to avoid further problems.
Check for proper combustion air supply and ventilation of boiler / mechanical room.
Check for combustible materials or chemicals stored too close to the boiler.
Test high limits by dialing lower settings, switching burner on/off. If low water
cut-off is installed, check and verify proper function according to manufacturer’s
instructions.
The following is an overview of scheduled service steps.
Regular service work ensures reliable, energy-efficient, and environmentally friendly operation.

11
5546 488 - 02
Vitocrossal 200, CM2 186 to 620 Operating Service and Maintenance
Service Schedule (continued)
Frequency Performed by 4Service
Annually Heating
Contractor
When circulating pump is field-installed or existing, check requirements for
maintenance or lubrication according to manufacturer’s specifications.
Check for gas-tight connection of gas piping, unions, gas valve and manifold.
Check proper ignition and gas burner operation.
Combustion test must be performed by a qualified heating contractor.
Periodically Heating
Contractor
Ensure functionality of low water cut-offs, during operation, based on supplier’s
instructions.
Inspect low- and/or high-pressure gas switch (if used).
Inspect main burner flame and follow burner manufacturer’s instruction manual
for detailed service and maintenance guidelines. Manual is shipped with burner.
All boilers and the boiler room must be kept free of high dust levels, high humidity,
aggressive vapor and/or chemicals containing chlorine.
Ensure proper boiler room ventilation.
Check and repair valves, fittings and pipes.
Combustion chamber door and flanges may need to be retightened and resealed.
IMPORTANTIMPORTANT
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.
The boiler should be cleaned at least once a year by a
qualified heating contractor or service agency.
Additional Maintenance Information
Danger of freezing
If the system is subject to freezing temperatures and
is not filled with antifreeze for protection, the system
including the boiler must be drained of water. The valve
before automatic feed valve (if installed) must be closed.
All other valves, air vents and drain valves must remain
open.
Long periods of shut-down
In case the heating boiler is shut down for an extended
period of time, i.e. after the heating season, the combustion
chamber, the flue gas collector and the vent pipe should
be properly cleaned to avoid corrosion. The heating
system can stay filled and under pressure. The remaining
condensate should be removed from the flue gas collector
by means of the front inspection service opening.
Water quality
The lifetime of the entire heating system is influenced by
the water quality. A water treatment system will protect
against damages caused by corrosion and lime formation.
Hard water conditions (i.e. calcium carbonate) must be
avoided as it will cause deposits to accumulate on the
heat exchanger surfaces.
If in any doubt about the water quality, please have a
proper water analysis done. Check with regional chemical
suppliers for boiler water treatment or with Viessmann
Manufacturing Company Inc. directly.

5546 488 - 02 Technical information subject to change without notice. Printed on environmentally friendly
(recycled and recyclable) paper.
Quick Reference
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Vitocrossal 200, CM2 186 to 620 Operating