Viessmann Vitocrossal 200 CM2 400 Operating instructions

Service Instructions
VITOCROSSAL 200
5584 071- 04 06/2015
for use by heating contractor
Vitocrossal 200
CM2 Series 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: 1445 to 2245 MBH
(423 to 658 kW)
Product may not be exactly as shown
IMPORTANT
H

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX 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.

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
Safety, Installation and Warranty Requirements
Safety
About these Installation 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 loss of life, 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.
Safety, Installation and Warranty Requirements (continued)
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.
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.

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620TX Service
Table of Contents
Safety
General Information
Start-up
Commissioning, Inspection and
Maintenance
Page
Safety, Installation and Warranty Requirements..............2
About these Installation Instructions..............................3
Equipment.................................................................6
Product Information.....................................................6
Important Regulatory and Installation Requirements........7
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..............8
Filling the Heating System with Water...........................9
Filling Condensate Trap with Water...............................9
Removing Covers......................................................10
Burner Overview.......................................................11
Steps - Commissioning, Inspection and Maintenance.....12
Commissioning the system......................................12
Select the gas type...............................................12
Conversion to liquid propane gas (LPG)....................13
Conversion to natural gas (NG)................................14
Converting gas type on burner control unit................15
Altitude adjustment................................................15
Reducing operational input (if required).....................16
Checking the static and the supply pressure..............16
Supply pressure for NG and LPG..............................17
Checking the Rotary Damper Setting........................17
Checking the CO2level...........................................18
Preparing the test..................................................18
CO2test at the upper heating input..........................18
CO2test at the lower heating output........................19
Displaying the ionization current...............................19
Shutting down the system.......................................20
Opening the boiler door..........................................20
Separating the neutralizing system (if installed)
from the boiler and connecting the drain hose............21
Cleaning the combustion chamber and heating surfaces..21
Checking gaskets and thermal insulation parts...........21
Checking all connections for leaks............................21
Cleaning and reconnecting the condensate drain system..22
Checking the condensate drain and the neutralizing
system (if installed)................................................22
Checking neutralization unit (if installed)...................22
Checking the cylinder burner assembly......................23
Checking the ignition and ionization electrodes..........24
Checking the 15A and 15B flue gas sensor...............25
Checking the 3A and 3B boiler temperature sensor....25
3A and 3B boiler temperature sensor description......26
Making the electrical burner connection.....................27
Cleaning the burner................................................28
Fitting the fan.......................................................28
Checking all gas connections for leaks......................29

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620TX Service
Commissioning, Inspection and
Maintenance
Burner Service
Boiler Control
Burner Control Unit
Flow Diagram
Connection Diagram
Troubleshooting
Parts
Specifications
Inspection and Maintenance
Table of Contents
Checking the Flue Side Gaskets/Seals.........................29
Flue side gaskets/seals............................................29
Checking the Diaphragm Expansion Vessel and
System Pressure.......................................................30
Check proper expansion tank and system pressure.....30
Water quality.........................................................30
Further Details Regarding the Individual Steps..............31
Gas inlet pressure monitoring switch - GDW1............32
Valve seat gas pressure monitoring switch - GDW2...32
Burner Component Overview......................................33
CM2 pre-mix cylinder burner 400/500/620/620TX.....33
Accessing the Burner.................................................34
Burner Control..........................................................34
Burner Control Coding Card.......................................35
Burner Control Programming Unit................................36
Gas Valve................................................................36
Ignition Unit.............................................................37
Ignition Cable...........................................................37
Motorized Burner Inlet Damper....................................38
Inlet Damper Servomotor...........................................38
Inlet Damper Linkage.................................................39
Plug Console with Relay.............................................39
Burner Fan...............................................................40
Burner Tube.............................................................40
Burner Door.............................................................43
Burner Door refractory..............................................44
Further Installation and Initial Start Up Instructions.......44
Boiler Water Temperature Sensor................................45
Flue Gas Temperature Sensor.....................................45
Burner Control Unit...................................................46
Display and programming unit.................................46
Operating display...................................................46
Information configuration display.............................48
Resetting Operating Parameters to their Factory Setting....50
Manual Mode and Service Display...............................50
Burner Control Unit Flow Diagram...............................51
Burner Control Unit Connection Diagram......................53
Faults......................................................................54
Fault display..........................................................54
Fault memory.........................................................54
Fault Codes..............................................................55
General process errors............................................55
Internal system fault...............................................58
Faults Without Fault Display.......................................58
Adjusting Coding Addresses at the Control Unit...........58
Parts Lists................................................................59
Technical Data.........................................................64
Cylinder Burner........................................................66
Maintenance Record..................................................68
Maintenance Schedule...............................................68
Page

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
General Information
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.
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 range 0 to 250º F
(121º C)
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 59 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.

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
Important Regulatory and Installation Requirements
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 67 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

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
Safety Instructions
General Information
Checking the high limit safety cut-out setting
The high limit safety cut-out is preset to 210° F (99° C).
If this temperature needs to be changed, this can only be
done by changing the coding card.
See the control section of the Installation
Instructions.
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.
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.
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.
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-authorised 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.
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.
CSD-1 Field Testing of High Limit Switches for Vitocrossal 200
CM2 boilers (models 400 to 620) – where required by law.
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 GW5B control on terminals 2-3
of 146 plug. (this will simulate a call for heat)- for boilers
used with Vitotronic 300-K cascade control, simply use
the emission test switch on GW5B control (top left corner
switch with ladder sign)
2 Set coding address 9B (external heat demand) to a 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)].
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 GW5B 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
menu 6 and external heat demand under address 9B).

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service Start-up
Filling the heating system with water and venting the system
For water hardness and pH value see page 30.
Note: Observe the water quality requirements on page 30.
Filling the Heating System with Water
Filling Condensate Trap with Water
1. Remove four screws and from the back then remove
the centre and bottom back panels.
2. Remove the siphon cup Aand fill with water
(otherwise flue gas may escape).
3. Check that the condensate can drain freely.
4. Refit the siphon cup A.
Note: The hose connection to the on-site condensate
system or to the neutralizing system must not
be permitted to sag; support hose where required.
Safety Instructions (continued)
Menu item “6“ is used to change the following operating parameters: (see page 49 for more detail)
Sub-menu
Item
Parameter Units/Scale Delivered
condition
1 Maximum operational input % of rated input 100%
2 Gas type 0=NG (natural gas)
1=LPG (liquid propane gas)
3 Not assigned -- --
4 Maximum boiler water temperature In °C from 5 to 127 95° C
5 Integral threshold value of controller In Kmin from 1 to 255 30 Kmin
6 Runtime optimization 0=minimum pause
1=integral method
1
7 Motorized vent damper 0=without damper
1=with damper
0
0 Reset all operating parameters to their delivered condition -- --

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
Removing Covers
Removing the front covers
1. Remove the M5 screw and set aside.
2. Lift and remove the top front panel.
3. Lift and remove the lower front panel.
Start-up
Removing the side covers
1. Remove the M6 screw (one per panel) on the top rail
and bottom support bracket. Then lift up and remove the
panel.

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service Start-up
Legend
ACompensating tube
CM2 400 burner
Burner Overview
Legend
ACompensating tube
Legend
ACompensating tube
CM2 500 burner
CM2 620/620 TX burner
Model CM2 400 500 620 620 TX
Rotary damper position degrees 30oN/A 20o20o
Compensation tubing connection Venturi mixing tube Adaptor plate Adaptor plate Adaptor plate
Orifice for Natural Gas 7 mm N/A 21.5 N/A N/A
Orifice Liquid Propane Gas 7 mm 14.0 14.8 17.2 17.2

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX 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. Permissible gas
pressure 4-14 “w.c.
3. Open the gas line shut-off valves.
4. Switch ON the main power (breakers).
5. Switch ON system ON/OFF switch at the control unit.
If fault indicator on the control unit illuminates and
burner control unit display A flashes, first press
reset button RB on the burner control unit.
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). Purge 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 55.
See the control section of the Installation
Instructions and neutralizing system Operating
Instructions.
7. Check the function of the neutralizing system.
Note: 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 initial run (see page 21).
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“
on page 67.
The Vitocrossal 200 CM2 boiler is for use with gases
whose characteristics fall within the following ranges.
Other types of gas such as LPG 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 400 7841184
Model 500 7841185
Model 620 7841186
Model 620 TX 7841985
Commissioning, Inspection, Maintenance

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service Commissioning, Inspection, Maintenance
Steps – Commissioning, Inspection and Maintenance (continued)
7. Remove four M5 hex nuts (8 mm wrench).
Detach the gas valve from flange E.
8. Place O-ring B on the gas valve. Install
rubberized cork gasket D onto the gas valve flange.
Install the LPG orifice C.
Note: Chamfer on LPG orifice must face gas valve.
9. Torque screws diagonally with 13.2 lb/in (1.5 Nm).
WARNING
Install LPG orifice. Incorrect 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 (see page 10).
5. Undo gas supply fitting A
6. Disconnect compensation tubing G connected
between the venturi tube and the gas valve.
10. Secure and tighten gas supply fitting A.
11. Reconnect the compensation tubing G (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 indicating 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.

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5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX 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 (see page 9).
5. Undo gas supply fitting A.
6. Disconnect compensation tubing G connected
between the venturi tube and the gas valve.
WARNING
Escaping gas leads to a risk of explosion.
Check all fittings for gas leaks.
Note: For commissioning, see page 12. Switch the burner
to maximum heating output. For this, activate the
emissions test switch at the boiler control unit.
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, Maintenance
10.Push compensation hose Gon to the gas valve.
11.Apply:
- Partial rating plate above CSA rating plate located
on top panel (behind the boiler control).
- Label indicating that this unit is equipped for NG
over the LPG label located on the gas valve.
- Label indicating that this unit has been converted to NG
from LPG next to the CSA rating plate (on the top panel).
- Fill out and fax conversion report.
12.Check all gas fittings for leaks.
WARNING
Escaping gas leads to a risk of explosion.
Check all fittings for gas leaks.
Note: The use of leak detecting spray can result in
incorrect functions. Leak detecting spray must
not come into contact with electrical components.
Boiler Model Dimension a in. (mm)
NG LPG
400 -- 0.52 (14.0)
500 0.85 (21.5) 0.58 (14.8)
620 -- 0.68 (17.2)
620 TX -- 0.68 (17.2)
Gas orifice dimensions (liquid propane gas) for boiler
models 400, 500, 620 and 620 TX
7. Remove four M5 hex nuts (8 mm wrench). Detach the
gas valve from flange E.
8. Remove and dispose of the LPG orifice C and the
rubberized cork gaskets D.
Install a new oriface and rubberized cork gasket (for
model 500 only, see gas orifice table).
Note: Chamfer on the NG orifice must face the
gas valve.
9. Tighten screws M5 x 16 diagonally.
Torque screws diagonally 13.2 lb/in (1.5 Nm).
10.Secure and tighten gas supply fitting A.

15
5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service Commissioning, Inspection, Maintenance
Steps – Commissioning, Inspection and Maintenance (continued)
Altitude adjustment
To implement the changes the burner has to be in
stand-by, Status “0”, Service “C”.
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 “C”.
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 type of gas 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)

16
5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX 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 “C”.
The maximum operational input of the burner can be set
to between 70 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 report (on page 67).
A CO measurement (see page 18) 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, Maintenance

17
5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service Commissioning, Inspection, Maintenance
Steps – Commissioning, Inspection and Maintenance (continued)
Supply pressure for NG and LPG.
1. Start the burner
Note: For commissioning, see page 12. 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.
Checking the Rotary Damper Setting
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 °
400 30 (close) / 0 (open)
500 --
620 20 (close) / 0 (open)
620 TX 20 (close) / 0 (open)
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 67).
4. Close the gas shut-off valve.
5. Remove the pressure tester and close test nipple A
(shown on page 16).

18
5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX 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 61).
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
400 8.9 0.2 10.6 0.2
500 8.9 0.2 10.6 0.2
620 8.9 0.2 10.6 0.2
620 TX 8.9 0.2 10.6 0.2
Commissioning, Inspection, Maintenance

19
5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service Commissioning, Inspection, 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 67).
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 67).
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
400 8.5 0.2 10.1 0.2
500 8.5 0.2 10.1 0.2
620 8.5 0.2 10.1 0.2
620 TX 8.5 0.2 10.1 0.2
Displaying the ionization current

20
5584 071- 04
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
Shutting down the system
1. Close the gas shut-off valve.
2. Switch OFF the main circuit breaker or the power supply
and safeguard against unauthorized reconnection.
3. Remove the boiler front cover (see page 10).
4. Disconnect power cable with plug 40. Then
disconnect the burner cables with plugs 3A/ 3B,
15A/15B, 40/156, 41 and in addition to plug
145 from the burner control unit and pull out of the
burner casing.
Opening the boiler door
1. Accessing the boiler (see page 10).
2. Loosen the retaining clamp and disconnect the
combustion air hose from the bottom of the air inlet
damper.
3. Remove the gas supply pipe.
4. Undo the six screws on the boiler door (if necessary,
undo connecting cable plug-in connections) and open
the boiler door.
Note: Scratches inside the combustion chamber can lead
to corrosion. Never put tools or other objects into
the combustion chamber.
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, Maintenance
CAUTION
The boiler door can cause damage and personal injury
if it swings shut. After opening the boiler door take
measures to prevent it from swinging shut.
CAUTION
Touching hot components can cause burns. Allow the
burner to cool down before beginning work.