Viessmann Vitocrossal 200 CM2 186 Original operating manual

Service Instructions
VITOCROSSAL 200
5584 109 - 10 12/2015
for use by heating contractor
Vitocrossal 200
CM2 Series 186 to 311
Gas condensing boiler with Pre-mix cylinder burner
Read and save these instructions
for future reference.
Please file in Service Binder
Heating input: 663 to 1112 MBH
194 to 326 kW
Product may not be exactly as shown
H
IMPORTANT

2
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Safety, Installation and Warranty Requirements
Safety
Please ensure that these instructions are read and understood before commencing installation. Failure to comply with
the instructions listed below and details printed in this manual can cause product/property damage, severe personal
injury, and/or loss of life. Ensure all requirements below are understood and fulfilled (including detailed information
found in manual subsections).
WARNING
Installers must follow local regulations with respect to
installation of carbon monoxide detectors. Follow the
Viessmann maintenance schedule of the boiler contained
in this manual.
Product documentation
Read all applicable documentation before commencing
installation. Store documentation near boiler in a
readily accessible location for reference in the future
by service personnel.
For a listing of applicable literature,
please see section entitled “Important
Regulatory and Safety Requirements”.
Warranty
Information contained in this and
related product documentation must
be read and followed. Failure to do
so renders the warranty null and void.
Licensed professional heating contractor
The installation, adjustment, service and maintenance
of this equipment must be performed by a licensed
professional heating contractor.
Please see section entitled
“Important Regulatory and Installation
Requirements”.
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” in the
“Installation Instructions”.
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 subsection entitled
“Mechanical room” and “Venting
requirements” 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” in the “Installation
Instructions”.
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.

3
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service Safety
Equipment
Tools
Assortment of flathead and Phillips screwdrivers
Pipe wrenches
Open-ended wrenches
Pipe sealant
Assortment of Hex keys
Flashlight
Approved leak detection fluid for natural gas and
propane gas
Cleaning supplies
Plastic hand brush
Cleaning/service brush
Vacuum cleaner
Clean rags
Testing/analysis equipment
(use only calibrated equipment)
Flue gas analyzer to measure % CO2or O2
(i.e. Bacharach fluid samplers or a suitable electronic
analyzer)
Multimeter to measure 0-120 VAC, 0-20 amps AC
and 0-100 microamps DC
Pressure gage to measure gas pressure 0 - 28 "w.c.
A non-electric MagnehelicR pressure gage (0 - 10 psig)
may also be used.
Carbon monoxide measuring equipment (0 - 400 ppm)
Bacharach calculator or suitable tables to calculate
efficiency
Stack thermometer dial settings 0 to 250ºF (121ºC)
din. NPT male to ¼ in. barb adaptor fitting, as well
as tubing for pressure measurement
Technical information
The following is a list of literature applicable to the
Vitocrossal 200, CM2 boiler:
Installation Instructions
Service Instructions
Operating Instructions
For installation of the heating system, please refer also
to the technical literature of other System Technology
devices:
Installation Instructions for Viessmann boiler control
Installation Instructions for Viessmann indirect-fired
hot water storage tank(s)
Installation Instructions for burner and accessories
Replacement parts
For a complete listing of replacement components, please
see Parts List starting on page 50 of these instructions.
Order replacement components from your Viessmann
distributor.
CAUTION
Use only original Viessmann recommended components
when replacing defective parts. Installation of incorrect
replacement parts can cause hazardous operation and
will void warranty.
Product Information
High efficiency gas-fired hot water condensing boiler.
For operation with modulating boiler water temperatures
in closed loop, forced circulation hot water heating
systems.
The Vitocrossal 200, CM2 boilers are CSA certified with
Viessmann burners which must be used in conjunction
with this boiler series.
The proper burner size must be verified and the burner
is factory adjusted so that the maximum input of the
appropriate boiler size is always observed. The gas burner
must always be installed according to the instructions
provided by the burner manufacturer.
The boiler model selected should be based on an accurate
heat loss calculation of the building. The boiler selected
must be compatible with the connected radiation.
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 Vitocrossal 200 boiler is suitable for a maximum
operating pressure of 75 psig and a maximum boiler
water temperature of 210°F (99°C).
This boiler does not require a flow switch.

4
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Table of Contents
Safety
General Information
Commissioning, Inspection and
Maintenance
Page
Safety, Installation and Warranty Requirements..............2
Equipment.................................................................3
Tools......................................................................3
Cleaning supplies.....................................................3
Testing/analysis equipment.......................................3
Technical information...............................................3
Replacement parts...................................................3
Product Information.....................................................3
About these Instructions..............................................5
Important Regulatory and Installation Requirements........5
Safety Instructions......................................................8
Target group..........................................................8
Regulations.............................................................8
If you smell gas......................................................8
If you smell flue gas................................................8
Working on the system.............................................8
Repair work............................................................8
Auxiliary components, spare and wearing parts...........8
Checking the high limit safety cut-out setting..............9
Filling the heating system with water and venting
the system..............................................................9
Filling siphon with water...........................................9
Steps - Commissioning, Inspection and Maintenance.....10
Commissioning the system......................................10
Select the gas type...............................................10
Conversion to liquid propane gas (LPG)....................11
Conversion to natural gas (NG)................................12
Converting gas type on burner control unit................13
Altitude adjustment................................................13
Reducing operational output (if required)...................14
Checking the static and the supply pressure..............14
Supply pressure for NG and LPG..............................15
Checking the Rotary Damper Setting
(CM2 246/311only)...............................................15
Checking the CO2level...........................................16
Preparing the test..................................................16
CO2test at the upper heating input..........................16
CO2test at the lower heating output........................17
Displaying the ionization current...............................17
Shutting down the system.......................................18
Opening the boiler door..........................................18
Separating the neutralizing system (if installed)
from the boiler and connecting the drain hose............18
Cleaning the combustion chamber and heating surfaces..18
Checking gaskets and thermal insulation parts...........18
Checking all connections for leaks............................18
Cleaning and reconnecting the condensate drain system..18
Checking the condensate drain and the neutralizing
system (if installed)................................................19
Checking neutralization unit (if installed)...................19
Checking the cylinder burner assembly......................19
Checking the ignition and ionization electrodes..........20
Closing the boiler door............................................20
Cleaning the burner................................................20
Making the electrical burner connection....................21
Checking all gas connections for leaks......................21
Checking the Flue Side Gaskets/Seals.........................21
Checking the Flue Gas Temperature Sensor..................22
Replacing the Flue Gas Temperature Sensor.................22
Checking the Boiler Temperature Sensor......................23
Replacing the Boiler Temperature Sensor.....................24

5
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Burner Service
Burner Control Unit
Flow Diagram
Troubleshooting
Parts
Specifications
Wiring
Maintenance Record
Table of Contents
Diaphragm Expansion Vessel and System Pressure........25
Check proper expansion tank and system pressures....25
Water Quality.........................................................25
Further Details Regarding the Individual Steps..............25
Fan pressure monitoring function (air pressure switch 1)..25
Combustion chamber pressure monitoring
(air pressure switch 2)............................................26
Gas Inlet pressure monitoring switch - GDW1............26
Valve seat pressure monitoring switch - GDW2..........26
Auxiliary Low Gas Pressure Switch.............................27
Gas Piping Components.............................................28
Burner Component Overview......................................29
CM2 pre-mix cylinder burner 186/246/311................29
Accessing the Boiler..................................................30
Burner Control..........................................................30
Burner Control Coding Card.......................................31
Burner Control Programming Unit................................32
Gas Valve (NG)........................................................32
Gas Valve (LPG)......................................................33
Air Pressure Switch...................................................34
2/2-Way Solenoid Valve (choke valve)
(for CM2 186 burner only).........................................34
Ignition Unit.............................................................35
Ignition Cable...........................................................35
Ignition Electrode Block.............................................36
Ionization Electrode Block...........................................36
Motorized Burner Inlet Damper....................................37
Inlet Damper Servomotor...........................................37
Inlet Damper Linkage.................................................38
Plug Console with Relay.............................................38
Burner Fan...............................................................39
Burner Tube.............................................................39
Burner Door.............................................................40
Burner Door Refractory..............................................41
Further Installation and Initial Start Up Instructions.......41
Burner Control Unit...................................................46
Resetting Operating Parameters to Factory Settings.........46
Manual Mode and Service Display...............................46
Burner Control Unit Flow Diagram...............................47
Faults......................................................................49
Fault display..........................................................49
Fault memory.........................................................49
Fault Codes..............................................................50
General process errors............................................50
Faults Without Fault Display.......................................53
Parts Lists................................................................54
Technical Data.........................................................60
Burner Control Unit Connection Diagram......................63
Maintenance Record..................................................64
Page

6
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
General Information
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.
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.
WARNING
Inhaling of fiberglass wool and/or ceramic fiber
materials is a possible cancer hazard. These materials
can also cause respiratory, skin and eye irritation.
Fiberglass wool and ceramic fiber materials
WARNING
Appliance materials of construction, products of
combustion and the fuel contain alumina, silica, heavy
metals, carbon monoxide, nitrogen oxides, aldehydes
and/or other toxic or harmful substances which can
cause serious injury or loss of life and which are
known to the State of California to cause cancer,
birth defects and other reproductive harm. Always
use proper safety clothing, respirators and equipment
when servicing or working nearby the appliance.
The state of California has listed the airborne fibers of
these materials as a possible cancer hazard through
inhalation. When handling these materials, special care
must be applied.
First aid measures
- If eye contact occurs, flush eyes with water to
remove dust. If symptoms persist, seek medical
attention.
- If skin contact occurs, wash affected areas gently
with soap and warm water after handling.
Suppliers of fiberglass wool products recommend the
following precautions be taken when handling these
materials:
- Avoid breathing fiberglass dust and contact with
skin and eyes.
- Use NIOSH approved dust/mist respirator.
- Wear long-sleeved, loose fitting clothing, gloves
and eye protection.
- Wash work clothes separately from other clothing.
Rinse washer thoroughly.
- Operations such as sawing, blowing, tear-out and
spraying may generate airborne fiber concentration
requiring additional protection.
Important Regulatory and Installation Requirements
Suppliers of ceramic fiber products recommend the
following first aid measures:
- Respiratory tract (nose and throat) irritation:
If respiratory tract irritation develops, move the
person to a dust free location.
- Eye irritation: If eyes become irritated, flush
immediately with large amounts of lukewarm water
for at least 15 minutes. Eyelids should be held away
from the eyeball to ensure thorough rinsing.
Do not rub eyes.
- Skin irritation: If skin becomes irritated, remove soiled
clothing. Do not rub or scratch exposed skin.
Wash area of contact thoroughly with soap and water.
Using a skin cream or lotion after washing may be
helpful.
- Gastrointestinal irritation: If gastrointestinal tract
irritation develops, move the person to a dust free
environment.

7
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Important Regulatory and Installation Requirements (continued)
Instructing the system user
The installer of the system is responsible to ensure the
system operator/ultimate owner is made familiar with
the functioning of the system, its activation, and its
shut-down.
Initial start-up
Initial start-up must be performed by a qualified heating
contractor. Completion of the Maintenance Record by
the heating contractor is also required.
Working on the equipment
The installation, adjustment, service, and maintenance of
this equipment must be done by a licensed professional
heating contractor who is qualified and experienced in
the installation, service, and maintenance of hot water
heating systems. There are no user serviceable parts on
this equipment.
Ensure main power supply to equipment, the heating
system, and all external controls has been deactivated.
Close main gas supply valve. Take precautions in all
instances to avoid accidental activation of power during
service work.
Technical literature
Literature applicable to all aspects of the Vitocrossal 200,
CM2:
- Technical Data Manual
- Installation Instructions
- Service Instructions
- Operating Instructions
- Wiring diagrams
Additional applicable literature:
- Viessmann boiler controls manuals
The following topics must be covered:
Proper system operation sequence. Explain the
equipment as well as the need for combustion air.
Demonstrate an emergency shut-down, what to
do and what not.
Explain that there is no substitute for proper
maintenance to help ensure safe operation.
The Maintenance Record is located on page 64 of
this manual.
Please carefully read this manual prior to attempting
start-up, maintenance or service. Any warranty is
null and void if these instructions are not followed.
For information regarding other Viessmann System
Technology componentry, please reference
documentation of the respective product.
Viessmann offers frequent installation and service
seminars to familiarize our partners with our products.
Please inquire.
The completeness and functionality of field supplied
electrical controls and components must be verified
by the heating contractor. These include low water
cut-offs, flow switches (if used), staging controls,
pumps, motorized valves, air vents, thermostats, etc.
Leave all literature at the installation site and advise
the system operator/ultimate owner where the literature
can be found. Contact Viessmann for additional copies.
General Information

8
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
If you smell flue gas
■Shut down the heating system.
■Ventilate boiler room.
■Close all doors in the living space
Working on the system
■Where gas is used as the fuel, close the main gas
shut-off valve and safeguard it against unintentional
reopening
■Isolate the system from the power supply (e.g. at the
separate fuse or a main switch) and check that it is
de-energized
■Safeguard the system against reconnection.
General Information
Target group
These instructions are intended exclusively for qualified
contractors.
■Work on gas installations must only be carried out
by a licensed professional heating contractor.
■Work on electrical equipment must only be carried
out by a qualified electrician.
■The system must be commissioned by the system
installer or a qualified person authorised by the installer.
■This appliance has not been designed to be operated
by individuals other than those qualified and trained.
Regulations
Observe the following when working on this system:
■Statutory regulations regarding the prevention of
accidents
■Statutory regulations regarding environmental
protection
■Codes of practice of the relevant trade associations.
Safety Instructions
If you smell gas
■Do not smoke. Prevent naked flames and sparks. Do not
press any switches for lights or electrical appliances.
■Close the gas shut-off valve.
■Open windows and doors.
■Remove all people from the danger zone.
■Notify your gas or electricity supply utility from outside
the building.
■Shut off the electricity supply to the building from a
safe place (outside the building).
WARNING
Escaping gas can lead to explosions which may result
in serious injury.
WARNING
Flue gas can lead to life threatening poisoning.
Note: Electronic assemblies can be damaged by
electrostatic discharges. Before beginning work,
touch grounded objects, such as heating or water
pipes, to discharge static loads.
Repair work
Note: Repairing components that fulfil a safety function
can compromise the safe operation of your system.
Replace faulty components only with original
Viessmann spare parts.
Auxiliary components, spare and wearing parts
Note: Spare and wearing parts that have not been tested
together with the system can compromise its function.
Installing non-authorized components and making
non-approved modifications or conversions can
compromise safety and may invalidate our warranty.
For replacements, use only original spare parts
supplied or approved by Viessmann.

9
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Checking the high limit safety cut-out setting
Never set the high limit safety cut-out higher than 210°F
(99°C).
See the control section of the Installation
Instructions.
Filling the heating system with water and venting the system
For water hardness and pH value see page 25.
Note: Observe the water quality requirements on page 25.
Filling siphon with water
1. Undo the siphon cup A and fill with water (otherwise
flue gas may escape).
2. Check that the condensate can drain freely.
3. Refit the siphon cup A.
General Information
Safety Instructions (continued)
CSD-1 Field Testing of High Limit Switches for Vitocrossal 200
CM2 boilers – where required by law.
As per ASME Boiler and Pressure Vessel Code, section IV,
subsection HG-613 TEMPERATURE CONTROL
requirements, Vitocrossal 200 CM2 hot water boilers are
protected from over-temperature by two temperature-
operated controls. These temperature control devices
conform to Standards for Limit Controls, and are accepted
by CSA, a nationally recognized testing agency.
Each boiler is equipped with a manual reset high
temperature limit control and a temperature control that
will cut off fuel supply when the system water
temperature reaches a preset operating temperature.
VIESSMANN IS NOT RESPONSIBLE FOR ANY DAMAGES
THAT THE FOLLOWING TEST PROCEDURE MAY RESULT
IN BY OVERHEATING THE SYSTEM.
The Vitocrossal 200 boilers are equipped with 2 RTD
temperature sensors that when activated on temperature
rise (high fixed limit of 210°F (99°C) disable the burner
to operate.
The fixed high limit, when tripped, produces a fault that
will require manual reset of the boiler control.
Fixed High Limit test procedure:
1. Install a jumper switch in GW6B control on terminals
2-3 of 146 plug. (this will simulate a call for heat)-
for multi boiler systems using the GW6B cascade +
lead boiler and lag boiler configuration, use the
emission test switch on GW6B control (top left corner
switch with ladder sign).
2. Set coding address 9B (external heat demand) to max.
of 241°F (116°C), as an example, higher than fixed
high limit temperature setting (if using emission test
switch, skip this step).
3. As described in the table on page 9, adjust item #4 Max.
boiler water temperature” under menu 6 of the burner
control (GC310) to a max. setting of 243°F (117°C),
as an example, higher than fixed high limit temperature
setting [factory default setting is 203°F (95°C)].
For testing of the adjustable limit ‘Max. boiler
temperature’ for a reduced temp. value as required
(e.g. 122°F (50°C).
4. Initiate a call for heat with the jumper switch on plug
146 (as in item 1 above) or press/activate emission
test switch if applicable, the burner will start.
5. Gradually and slowly throttle the water flow to the
boiler.
6. Observe temperature on the GW6B control.
7. Once the temperature reached the fixed high limit
setting, burner control will have a hard lock out with
F F2 fault displayed. Burner fan stays on for 10 min.
The fault can only be manually reset once the water
temperature in the boiler drops.
8. Reset to original settings as needed (item #4 under
submenu 6 and external heat demand under address
9B).

10
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Commissioning the system
See the control section of the Installation
Instructions and neutralizing system Operating
Instructions.
1. Check the heating system pressure. Permissible boiler
operating pressure: 75 psi.
2. Check the gas supply pressure.
3. Open the gas line shut-off valves.
4. Switch ON the main power (breakers).
5. Switch ON system ON/OFF switch Bat the control
unit. If fault indicator Aon the control unit illuminates
and burner control unit display C flashes, first press
reset button RD on the burner control unit.
Burner faults can also be acknowledged and reset at the
GW6B boiler control. Refer to the Vitotronic 300 GW6B
Installation and Service Instructions.
Steps – Commissioning, Inspection and Maintenance
WARNING
Failure to ensure that all flue gases have been safely
vented to the outdoors can cause property damage,
severe personal injury, or loss of life. Flue gases may
contain deadly carbon monoxide.
Note: The system can enter a fault state during
commissioning if there is insufficient gas in the
supply line (the fault indicator on the control unit
illuminates). Vent the gas supply line again and
reset the burner control unit.
Remove air from the gas line with an approved
gas purge burner or vent outdoors.
6. Match the coding card at the burner control unit
according to the chart on this page. Also refer to
page 31.
See the control section of the Installation
Instructions and neutralizing system Operating
Instructions.
7. Check the function of the neutralizing system.
Note: Refer to neutralizing system operating instructions.
8. Check all gaskets and plugs, and retighten if necessary
Note: We recommend you check all connections on the
heating water side for leaks after approximately
500 hours run (see page 18).
9. Check the boiler door a few days after commissioning
and retighten all screws.
Select the gas type
1. The boiler is factory set to operate with natural gas.
See the following subsection for conversion instructions
to liquid propane gas.
2. Ensure that the fuel type listed on the boiler rating plate
is the correct type for the installation being attempted.
3. Record the gas type in the “Maintenance Record“
in this manual.
The Vitocrossal 200 CM2 boiler is for use with gases
whose characteristics fall within the following ranges.
Other types of gas such as LNG with different heating
value can be used.
Natural Gas Liquid Propane Gas
Heating value
(gross) Btu/ft3970 to 1100 2466 to 2542
Specific gravity 0.57 to 0.70 1.522 to 1.574
Ultimate carbon
dioxide (CO2) % 11.7 to 12.2 13.73 to 13.82
CM2 Burner Coding Card Part No
Model 186 7842311
Model 246 7842312
Model 311 7842313
Commissioning, Inspection and Maintenance

11
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service Commissioning, Inspection and Maintenance
Steps – Commissioning, Inspection and Maintenance (continued)
7. Remove four 8 mm hex nuts. Detach the gas valve
from flange C.
8. Remove and discard O-ring F from gas valve. Install
rubberized cork gasket E onto the gas valve face.
Install the LPG orifice D (with pin). Install second
rubberized cork gasket on top of the LPG orifice.
WARNING
Escaping gas leads to a risk of explosion.
Check all fittings for gas leaks.
WARNING
Install LPG orifice with the pin at the top and to the rear.
Wrong installation of the orifice will lead to leakage.
Conversion to liquid propane gas (LPG)
(The LPG conversion kit is supplied with the burner)
1. Close the gas shut-off valve.
2. Switch OFF the system ON/OFF switch at the boiler
control unit.
3. Switch OFF the main boiler circuit breaker (outside
the boiler room) or the power supply and prevent
unauthorized reconnection.
4. Remove boiler front cover.
9. Secure gas valve, orifice Dand rubberized cork
gaskets Eto the flange of the mixing system C.
Torque nuts diagonally with 17.7 lb.in (2.0 Nm).
10. Secure and tighten gas supply fitting A.
11. Reconnect the compensation tubing B (connected
between the venturi tube and the gas valve).
12.Apply:
- Partial rating plate above CSA rating plate located
on top panel (behind the boiler control).
- Label Gindicating that this unit is equipped for NG
over the LPG label located on the gas valve.
- Label indicating that this unit has been converted from
LPG to NG next to the CSA rating plate (on the top panel).
- Fill out and fax conversion report.
13.Check all gas fittings for leaks.
Note: The use of leak detecting spray can result in
incorrect functions. Leak detecting spray must
not come into contact with electrical components.
5. Undo gas supply fitting A
6. Disconnect compensation tubing B connected
between the venturi tube and the gas valve.
Boiler Model Dimension a in. (mm)
186 0.38 (9.7)
246 0.48 (12.2)
311 0.54 (13.6)
Gas orifice dimensions (liquid propane gas) for boiler
models 186 to 311
Pin

12
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Steps – Commissioning, Inspection and Maintenance (continued)
Conversion to natural gas (NG)
1. Close the gas shut-off valve.
2. Switch OFF the system ON/OFF switch at the boiler
control unit.
3. Switch OFF the main boiler circuit breaker (outside
the boiler room) or the power supply and prevent
unauthorized reconnection.
4. Remove boiler front cover.
WARNING
Escaping gas leads to a risk of explosion.
Check all fittings for gas leaks.
5. Undo gas supply fitting A.
6. Disconnect compensation tubing B connected
between the venturi tube and the gas valve.
7. Remove four 8 mm hex nuts. Detach the gas valve
from flange C.
8. Remove and dispose of the LPG orifice D (with pin)
and the rubberized cork gaskets E. Install a new
rubberized cork gasket between the gas valve and
flange C.
Note: No separate orifice is necessary for Natural Gas.
9. Secure gas valve, to the flange of the mixing system
C. Torque nuts diagonally with 17.7 lb.in (2.0 Nm).
10. Secure and tighten gas supply fitting A.
11. Reconnect the compensation tubing B (connected
between the venturi tube and the gas valve).
12.Apply:
- Partial rating plate above CSA rating plate located
on top panel (behind the boiler control).
- Label Findicating that this unit is equipped for LPG
over the NG label located on the gas valve.
- Label indicating that this unit has been converted from
NG to LPG next to the CSA rating plate (on the top
panel).
- Fill out and fax conversion report.
13.Check all gas fittings for leaks.
Note: The use of leak detecting spray can result in
incorrect functions. Leak detecting spray must
not come into contact with electrical components.
Commissioning, Inspection and Maintenance
Note: For commissioning, see page 10. Switch the burner
to maximum heating output. For this, activate the
emissions test switch at the boiler control unit.

13
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service Commissioning, Inspection and Maintenance
Steps – Commissioning, Inspection and Maintenance (continued)
Altitude adjustment
To implement the changes the burner has to be in
stand-by, Status “0”, Service “0”.
1. Press button SF, hold for more than 2 seconds and
the “ " in the display area D will flash.
2. Press button YEuntil “6” appears in the Service
display B.
3. Press button SF, until “6” appears in the Status
display A.
4. Press button YEuntil “3” appears in the Service
display B.
5. Press button SF until “3” appears in the Status
display A.
6. The current altitude will be displayed under Service
display B(0 = Low Altitude, or 1 = High Altitude).
7. Press buttons YEor BGuntil “1” appears for
“High Altitude”. “1” will be displayed under Service
for a short time.
8. Press button SFto confirm. Set again to “1” if “0”
appears.
9. Press button SFto exit setting mode and return to
operating mode.
10.Press button RCfor more than 2 seconds and the
system restarts and the settings will be applied.
11.Fill out and apply “Altitude Conversion” label next to
Rating Plate.
12.Fill out and fax conversion report.
Note: Each time the burner restarts, the setup parameters,
max. input, gas type and altitude will show up on
the display as in the table below.
Max. Input: “1; 70...100” = Modulation Level %
Gas Type: “2; nG” = Natural Gas or
“2; LPG” = Liquid Propane Gas
Altitude: “3; LA”
= Low Altitude
“3; HA” = High Altitude)
Converting gas type on burner control unit
To implement the changes the burner has to be in
stand-by, Status “0”, Service “0”.
1. Press button SF, hold for more than 2 seconds
and the “ ” in the display area Dwill flash.
2. Press button YEuntil “6” appears in the Service
display B.
3. Press button SF, until “6” appears in the Status
display A.
4. Press button YEuntil “2” appears in the Service
display B.
5. Press button SF until “2” appears under Status A.
6. The current gas type will be displayed under Service
window (0 = NG, or 1 = LPG).
7. Press buttons
YEor BGto set “0” for NG and
“1” for LPG.
8. Press button SFto confirm. Upon successful
completion “1” will be displayed under Service for
a short time. Repeat procedure if “0” appears.
9. Press button SFto exit setting mode and return
to operating mode.
10.Press button RCfor more than 2 seconds and the
system restarts and the settings will be applied.
Note: Each time the burner restarts, the setup parameters,
max. input, gas type and altitude will show up on
the display as in the table below.
Max. Input: “1; 70...100” = Modulation Level %
Gas Type: “2; nG” = Natural Gas or
“2; LPG” = Liquid Propane Gas
Altitude: “3; LA”
= Low Altitude
“3; HA” = High Altitude)
Note: Burner commissioning can be done either at the
burner control interface or at the GW6B boiler
control under coding level 2 ‘combustion controller’
group. Refer to the Vitotronic 300 GW6B
Installation and Service Instructions.

14
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Steps – Commissioning, Inspection and Maintenance (continued)
Reducing operational input (if required)
To implement the changes the burner has to be in
stand-by, Status “0”, Service “0”.
The maximum operational input of the burner can be set
to between 0 and 100 % if necessary:
“100“ = 100% = upper heating input,
“0“ = 0% = lower heating input
1. Press button SFand hold for longer than 2 seconds
and “ “in the display area D will flash.
2. Press button YEuntil “6” appears in the service
display B.
3. Press button SF, until “6” appears in the status
display A.
4. Press button SF and “1“ will appear in the status
display Aand the current value for the maximum
operational input is shown in % in the service
display B.
5. Press button YEor BGfor the required maximum
operational input.
6. Press button SF to confirm. If applied successfully,
“1“ will be shown in the service display B.
If the adjustment failed, service display Bwill show “0”.
7. Press button SF to switch to the operating display.
8. Press button RCfor more than 2 seconds and the
system restarts and the settings will be applied.
WARNING
Ensure that there is no open flame in the room.
WARNING
Never purge a gas line into a combustion chamber. Never
use matches, candles, flame, or other sources of ignition
for purpose of checking leakage. Use a soap-and-water
solution to check for leakage. Failure to follow this warning
could result in fire, explosion, personal injury, or death.
IMPORTANT
The burner is automatically ignited and starts operation
after a safety time has elapsed.
During initial start-up, the unit may indicate a fault because
of air in the gas supply pipe (especially for liquid propane gas).
After approximately 5 seconds, press the reset button R C
to reset the burner. The ignition procedure is repeated.
This boiler employs a direct spark ignition system.
1. Close the gas shut-off valve.
2. Undo the screw inside test nipple A.Do Not Remove.
3. Connect the pressure tester at test nipple A.
4. Open the gas shut-off valve.
5. Check the static pressure (max. 14“w.c.).
6. Record the actual value in the “Maintenance Record“
in this manual.
A CO measurement (see page 16) must be taken before
and after working on gas appliances to eliminate risks to
health and to guarantee the satisfactory condition of the
system.
IMPORTANT
Checking the static and the supply pressure
Note: Each time the burner restarts, the setup parameters,
max. output, gas type and altitude will show up on
the display as in the table below.
Commissioning, Inspection and Maintenance

15
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Steps – Commissioning, Inspection and Maintenance (continued)
Commissioning, Inspection and Maintenance
Supply pressure for NG and LPG.
1. Start the burner
Note: For commissioning, see page 10. Switch the burner
to maximum heating output. For this, activate the
emissions test switch at the boiler control unit.
2. Measure the supply pressure (running pressure). Use
suitable measuring instruments calibrated with a
minimum resolution of 0.04 “w.c. for measuring the
supply pressure.
Value must be:
Supply pressure with: Corrective action
Natural gas Liquid propane gas
under 4”w.c. under 10”w.c. Do not attempt adjustment. Call local gas utility
4 to 14“w.c. 10 to 14”w.c. Start up boiler.
over 14”w.c over 14”w.c. Do not attempt adjustment. Call local gas utility to decrease pressure.
Boiler valve must not be exposed to pressure over 14 ”w.c.
Note: The supply pressure should be between 4“w.c.
and 14”w.c. The gas pressure switch for the inlet
pressure test/check is factory set to 4”w.c.
Never alter this setting.
3. Record the actual value in the report (on page 53).
4. Close the gas shut-off valve.
5. Remove the pressure tester and close test nipple A
(shown on page 14).
The electro-mechanical inlet air damper reduces the
amount of air during ignition timing, for a smoother
ignition of the burner.
1. Open the gas shut-off valve.
2. Check the position of the rotary damper in burner
idle mode. The rotary damper windows B must be
completely open and the graduated collar D on the
air damper motor must be set to “0“ relative to mark C.
3. Check whether compensation tubing A has been
connected between the gas valve and venturi mixing
pipe.
4. Start the burner.
5. Check the position of the rotary damper during the
start-up phase. The rotary damper windows B must
be almost closed for approximately 5 seconds, during
which time the graduated collar D is set as follows:
Boiler Models Rotary damper setting in °
246 35 (close) / 0 (open)
311 35 (close) / 0 (open)
Checking the Rotary Damper Setting (CM2 246/311 only)

16
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
CO2Test at the upper heating input
1. Press button YEuntil the service display B has
incremented to “100“(= 100 %).
2. Check the CO2level at the flue pipe.
3. If the CO2level must be adjusted:
■Remove cap B.
■Turn adjusting screw A in small increments
(3 mm Allen key) until the CO2level falls within the
specified range:
- Turning clockwise →CO2level falls (less gas)
- Turning counter-clockwise →CO2level rises (more
gas)
4. Record the actual value in the report (on page 64).
Steps – Commissioning, Inspection and Maintenance (continued)
Checking the CO2level
Preparing the test
1. Open the gas shut-off valve.
2. Start the burner with the emissions test switch enabled
at the boiler control unit.
3. At the same time, press button SF and button
BGand hold for longer than 2 seconds.
The display will then show the following:
■Under Status A: “P“ (= relay test)
■Under Service B: Modulation level in %
“100“ = 100% = upper heating input,
“0“ = 0% = lower heating input
Boiler Model Permissible CO2 content in % @ Hi-Fire
NG LPG
186 8.5 - 9.5 10.0 - 11.0
246 8.5 - 9.5 10.0 - 11.0
311 8.5 - 9.5 10.0 - 11.0
Commissioning, Inspection and Maintenance

17
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service Commissioning, Inspection and Maintenance
CO2Test at the lower heating output
1. Press button BG until the service display Bhas
counted down to “0“ (lower heating output).
2. Check the CO2 level at the flue pipe.
Note: The CO2content must always be lower in partial
load than it is in full load.
3. If the CO2content must be adjusted:
■Remove cover B (see illustration below)
■Turn adjusting screw A (see illustration below) in
small increments (Torx 40) until the CO2content falls
within the specified range:
- Turning clockwise →CO2content increases
(more gas)
- Turning counter-clockwise →CO2content falls
(less gas)
4. Record the actual value in the report (on page 64).
Rechecking the values:
Regulate again to the upper and lower heating output using
the burner programming unit. If the values do not match the
permissible CO2content according to the table, repeat the
steps for the upper and lower heating output.
5. On the burner control press SF and BG
simultaneously for more than 2 seconds. The burner
will change to the operating mode.
Steps – Commissioning, Inspection and Maintenance (continued)
Note: The ionization current must be called up via the
burner control unit. It is not possible to measure
the ionization current using a multimeter.
1. Press button SF, hold for more than 2 seconds and
the “ “ in the display area D will flash.
2. Press button YE until “5“ appears in the service
display B.
3. Press button SFand “5“ will appear in the status
display A.
4. Press button YE until “.3“ appears in the service
display B.
5. Press button SF and “3“will appear in the status display
A(during operation the ionization current is displayed
under service display B(e.g. 30 = 3.0 μA).
6. Start the burner with the emissions test switch at the
boiler control unit.
7. Read the ionization current.
Note: The ionization current should be at least 3 A
for approximately 2 to 3 seconds after the gas
valve has been opened and during operation.
8. Record the actual value in the report (on page 64).
9. Press button SF, hold for more than 2 seconds and
the “ “ in the display area D will flash.
10. Press button YE until “5“ appears in the service
display B.
11. Press button SFand “5“ will appear in the status
display A.
12. Press button YE until “0“ appears in the service
display B.
13. Press button SFto switch to the operating display.
Boiler Model Permissible CO2 content in % @ Low-Fire
NG LPG
186 8.0 - 9.0 9.5 - 10.5
246 8.0 - 9.0 9.5 - 10.5
311 8.0 - 9.0 9.5 - 10.5
Displaying the ionization current

18
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Cleaning the combustion chamber and heating surfaces
Thoroughly clean the combustion chamber and heating
surfaces with a water jet.
Note: Scratches on parts that are in contact with flue gas
can lead to corrosion. Only use plastic brushes, not
wire brushes nor sharp objects.
For normal cleaning, flush the heating surfaces thoroughly
with a water jet. You may use cleaning agents if you
notice stubborn residues, surface discoloration or soot
deposits. For this, observe the following:
■Only use solvent-free cleaning agents. Ensure that no
cleaning agent gets between the boiler body and the
thermal insulation.
Note: The cleaning agent must not contain
hydrocarbon-based solvents or potassium.
Follow the cleaning agents instructions.
■Remove deposits of combustion by-products with
alkaline agents containing tenside.
■Remove coatings and surface discoloration (yellowish
brown) with phosphoric acid-based Antox 75 E Plus or
citric acid-based CitiSurf 3050 (by Stellar Solutions Inc.
■Rinse thoroughly with water.
Checking gaskets and thermal insulation parts
1. Check gaskets and the sealing rope in the boiler door
for damage.
2. Check the thermal insulation components of the boiler
door for possible damage.
3. Replace any damaged parts.
Checking all connections for leaks
1. Check all connections on the heating water side and
sensor well Afor leaks.
Note: Also check the connections to control equipment
and to the minimum pressure switch (low water
indicator) for leaks.
Shutting down the system
1. Switch OFF the main circuit breaker or the power supply
and safeguard against unauthorized reconnection.
2. Remove the boiler front cover.
3. Release burner cables with plug fA and lÖ from the
burner control unit and route them out of the burner
casing.
4. Close the gas shut-off valve.
Opening the boiler door
1. Remove the gas supply pipe.
2. Undo the four screws on the boiler door and open
the door.
Note: Scratches inside the combustion chamber can lead
to corrosion. Never put tools or other objects into
the combustion chamber.
Separating the neutralizing system (if installed) from the
boiler and connecting the drain hose
1. Separate hose A to the neutralizing system from
siphon B.
2. Connect drain or cleaning hose C to the siphon and
run it to the drain.
Steps – Commissioning, Inspection and Maintenance (continued)
WARNING
Mains voltage can be extremely dangerous.
For maintenance work, isolate the system from the
power supply.
Commissioning, Inspection and Maintenance

19
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service Commissioning, Inspection and Maintenance
Steps – Commissioning, Inspection and Maintenance (continued)
Checking the cylinder burner assembly
1. Undo fitting on the gas supply pipe.
2. Undo the screws on the boiler door and open the door.
3. Remove side panels Band C.
4. Check the wire mesh of the cylinder burner assembly
E for damage.
4. Replace cylinder burner assembly Eif required.
See Replacement Instructions for burner.
IMPORTANT
If the condensate does not drain freely, the condensate
will accumulate in the bottom part of the boiler, resulting
in burner shut-down (fault message).
WARNING
Escaping gas leads to a risk of explosion.
Close the gas shut-off valve.
Check neutralization unit (if installed)
1. Check the pH value of the condensate with a pH
measuring strip (field supplied). If the pH value is
less than 6.5, replace granulate.
2. If contaminated - rinse the neutralization unit with
tap water.
3. Add granulate as marked.
IMPORTANT
The granulate is consumed as it neutralizes the condensate.
The red marking indicates the minimum filling level.
See Neutralization Unit ”Installation Instructions”.
Note: For maintenance purposes, route the gas supply
pipe A on the opposite side of the burner D
door hinges.
Cleaning and reconnecting the condensate drain system
Note: Clean the inside of the condensate drain system
at least annually.
1. Pull drain or cleaning hose C off.
2. Clean the inside of the condensate drain system
(hose, pipe).
3. Clean the neutralizing system (if installed) in
accordance with the manufacturer‘s instructions.
See Neutralization System Operating Instructions.
Note: You can obtain the neutralizing granulate from
Viessmann.
4. Release and flush lower part D of siphon B.
5. Fill lower part D of siphon B with water and
reassemble.
6. Install hose A of the neutralizing system to the siphon.
Checking the condensate drain and the neutralizing
system (if installed)
Add water to the combustion chamber.
Note: The water must flow from the condensate drain
without back pressure.
If necessary, clean the condensate drain again.

20
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Steps – Commissioning, Inspection and Maintenance (continued)
Checking the ignition and ionization electrodes
Check the ignition electrodes and the ionization electrode
for correct gap towards the cylinder burner assembly and
damage (replace if required).
See burner component Installation Instructions.
Ignition electrodes
Ionization electrode
Closing the boiler door
Note: Tighten the boiler door screws evenly across with
a torque of approximately 13 lb.ft (18 Nm).
Cleaning the burner
1. Loosen the retaining clamp and disconnect the
combustion air flex hose A.
2. Visually inspect the combustion air hose Aand
venturi mixing pipe B.
3. If cleaning is required remove the venturi B (refer
to page 35 for burner fan removal procedures) and
clean the venturi pipe, fan casing and impeller with
low pressure compressed air.
4. To clean the burner, vacuum the inside and outside of
the burner tube C(refer to page 39 for burner tube
removal procedures).
IMPORTANT
Use a soft upholstery brush when cleaning the outside of
the burner tube to prevent damage.
CAUTION
Working with compressed air may lead to serious injury.
Never direct the air jet at yourself or others.
Always wear appropriate personal protective equipment
and clothing.
Commissioning, Inspection and Maintenance