Viessmann Vitocrossal CRU 800 Operating instructions

Service instructions
for contractors
VIESMANN
Vitocrossal
Type CRU, 800 and 1000 kW
Gas condensing boiler
For open flue and room sealed operation
Permissible operating pressure 6 bar
VITOCROSSAL
5833296 GB 6/2018 Please keep safe.

2
Please follow these safety instructions closely to
prevent accidents and material losses.
Safety instructions explained
Danger
This symbol warns against the risk of injury.
!Please note
This symbol warns against the risk of material
losses and environmental pollution.
Note
Details identified by the word "Note" contain additional
information.
Target group
These instructions are exclusively intended for quali-
fied contractors.
■Work on gas installations may only be carried out by
a registered gas fitter.
■Work on electrical equipment may 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.
Regulations to be observed
■National installation regulations
■Statutory regulations for the prevention of accidents
■Statutory regulations for environmental protection
■Codes of practice of the relevant trade associations
■All current safety regulations as defined by DIN, EN,
DVGW, TRGI, TRF, VDE and all locally applicable
standards
aÖNORM, EN, ÖVGW G K directives,
ÖVGW-TRF and ÖVE
cSEV, SUVA, SVGW, SVTI, SWKI, VKF and
EKAS guideline 1942: LPG, part 2
Safety instructions for working on the system
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. by
removing the separate fuse or by means of a mains
isolator, and check that it is no longer live.
■Safeguard the system against reconnection.
■Wear suitable personal protective equipment when
carrying out any work.
Danger
Hot surfaces and fluids can lead to burns or
scalding.
■Before maintenance and service work, switch
OFF the appliance and let it cool down.
■Never touch hot surfaces on the boiler, burner,
flue system or pipework.
!Please note
Electronic assemblies can be damaged by elec-
trostatic discharge.
Prior to commencing work, touch earthed
objects such as heating or water pipes to dis-
charge static loads.
Repair work
!Please note
Repairing components that fulfil a safety func-
tion can compromise the safe operation of the
system.
Replace faulty components only with genuine
Viessmann spare parts.
Safety instructions
Safety instructions
5833296

3
Auxiliary components, spare and wearing parts
!Please note
Spare and wearing parts that have not been tes-
ted together with the system can compromise its
function. Installing non-authorised components
and making non-approved modifications or con-
versions can compromise safety and may inva-
lidate our warranty.
For replacements, use only original spare parts
supplied or approved by Viessmann.
Safety instructions for operating the system
If you smell gas
Danger
Escaping gas can lead to explosions which may
result in serious injury.
■Do not smoke. Prevent naked flames and
sparks. Never switch lights or electrical appli-
ances on or off.
■Close the gas shut-off valve.
■Open windows and doors.
■Evacuate any people from the danger zone.
■Notify your gas or electricity supply utility from
outside the building.
■Have the power supply to the building shut off
from a safe place (outside the building).
If you smell flue gas
Danger
Flue gas can lead to life threatening poisoning.
■Shut down the heating system.
■Ventilate the installation site.
■Close doors to living spaces to prevent flue
gases from spreading.
What to do if water escapes from the appliance
Danger
If water escapes from the appliance there is a
risk of electrocution.
Switch OFF the heating system at the external
isolator (e.g. fuse box, domestic distribution
board).
Danger
If water escapes from the appliance there is a
risk of scalding.
Never touch hot heating water.
Condensate
Danger
Contact with condensate can be harmful to
health.
Never let condensate touch your skin or eyes
and do not swallow it.
Flue systems and combustion air
Ensure that flue systems are clear and cannot be
sealed, for instance due to accumulation of conden-
sate or other external causes.
Avoid continuous condensate disposal with a wind pro-
tector.
Ensure an adequate supply of combustion air.
Inform system users that subsequent modifications to
the building characteristics are not permissible (e.g.
cable/pipework routing, cladding or partitions).
Danger
Leaking or blocked flue systems, or an inade-
quate supply of combustion air can cause life
threatening poisoning from carbon monoxide in
the flue gas.
Ensure the flue system is in good working order.
Vents for supplying combustion air must be non-
sealable.
Extractors
Operating appliances that exhaust air to the outside
(extractor hoods, extractors, air conditioning units, etc.)
can create negative pressure. If the boiler is operated
at the same time, this can lead to a reverse flow of flue
gas.
Danger
The simultaneous operation of the boiler and
appliances that exhausts air to the outside can
result in life threatening poisoning due to a
reverse flow of flue gas.
Fit an interlock circuit or take suitable steps to
ensure an adequate supply of combustion air.
Safety instructions
Safety instructions (cont.)
5833296

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1. Information Symbols ................................................................................................. 5
Intended use .......................................................................................... 5
Product information ................................................................................ 6
■System examples ............................................................................... 6
2. Commissioning, inspec-
tion, maintenance
Steps - commissioning, inspection and maintenance ............................ 7
3. Burner control unit Burner control unit VUC 310 .................................................................. 31
■Display and programming unit ............................................................ 31
■Operating display ................................................................................ 31
■Selecting the menu ............................................................................. 32
■Calling up information and resetting meters ....................................... 32
■Changing the configuration ................................................................. 33
■Resetting operating parameters to their delivered condition .............. 35
■Setting the modulation level for manual operation ............................. 35
Flow diagram for burner start ................................................................. 36
■Description of state ............................................................................. 37
4. Troubleshooting Fault display ........................................................................................... 38
■Calling up the fault history (fault memory) .......................................... 38
Fault codes with display on burner control unit ...................................... 39
■General process errors: Displayed fault codes ................................... 39
■Internal system faults: Displayed fault codes and detailed fault
codes .................................................................................................. 42
Faults without fault display ..................................................................... 43
5. Parts lists Overview of assemblies ......................................................................... 45
Boiler assembly ..................................................................................... 46
Casing assembly ................................................................................... 48
MatriX-Disk burner assembly ................................................................. 50
Burner control unit assembly ................................................................. 52
Vitotronic control unit assembly ............................................................. 54
6. Component overview Overview of burner components ............................................................ 56
7. Function description Air pressure switch ................................................................................ 57
■Fan pressure monitoring function (LDW1) .......................................... 57
■Combustion chamber pressure monitoring function (LDW2) .............. 57
Boiler water temperature sensors and flue gas temperature sensors ... 57
8. Connection diagrams Burner control unit connection diagram ................................................. 58
9. Reports ................................................................................................................ 61
10. Specification ................................................................................................................ 64
11. Final decommissioning Final decommissioning and disposal ..................................................... 67
12. Certificates Declaration of conformity ....................................................................... 68
Manufacturer's certificate according to the 1st BImSchV [Germany] .... 68
13. Keyword index ................................................................................................................ 69
Index
Index
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Symbol Meaning
Reference to other document containing
further information
1.
Step in a diagram:
The numbers correspond to the order in
which the steps are carried out.
Warning of material losses and environ-
mental pollution
Live electrical area
Pay particular attention.
■Component must audibly click into place.
or
■Acoustic signal
■Fit new component.
or
■In conjunction with a tool: Clean the sur-
face.
Dispose of component correctly.
Dispose of component at a suitable collec-
tion point. Do not dispose of component in
domestic waste.
The steps in connection with commissioning, inspec-
tion and maintenance are found in the "Commission-
ing, inspection and maintenance" section and identified
as follows:
Symbol Meaning
Steps required during commissioning
Not required during commissioning
Steps required during inspection
Not required during inspection
Steps required during maintenance
Not required during maintenance
Intended use
The appliance is only intended to be installed and
operated in sealed unvented heating systems that
comply with EN 12828, with due attention paid to the
associated installation, service and operating instruc-
tions as well as the details in the datasheet.
It is only designed for the heating up of heating water.
Commercial or industrial usage for a purpose other
than the heating up of heating water shall be deemed
inappropriate.
Intended use presupposes that a fixed installation in
conjunction with permissible components designed for
this purpose has been carried out.
Every other use will be deemed to be inappropriate.
Any resulting losses are excluded from the manufac-
turer's liability.
Any usage beyond this must be approved by the man-
ufacturer for the individual case.
Intended use also includes the adherence to mainte-
nance and inspection intervals.
Information
Symbols
5833296
Information

6
Vitocrossal, type CRU
■Gas condensing boiler, 800 kW and 1000 kW rated
heating output with modulating MatriX-Disk burner
for natural gas E and natural gas LL
■Permissible operating pressure for the heating sys-
tem: 6 bar/0.6 MPa.
System examples
For available system examples, see www.viessmann-
schemes.com
Information
Product information
5833296
Information

7
Commissioning steps
Inspection steps
Maintenance steps Page
•1. Filling the heating system with water and venting the system...................................... 9
•2. Filling the trap with water.................................................................................................. 9
• • 3. Checking the sensor well and all connections on the heating water side for
tightness............................................................................................................................. 10
•4. Checking the electrical connections................................................................................ 11
•5. Checking the gas type....................................................................................................... 11
•6. Setting the gas type........................................................................................................... 12
••• 7. Commissioning the system............................................................................................... 12
••• 8. Checking the flue gas damper.......................................................................................... 13
•9. Reducing the maximum heating output (if required)...................................................... 14
••• 10. Checking the static pressure and supply pressure........................................................ 14
••• 11. Measuring the CO2 content............................................................................................... 16
• • 12. Measuring the CO content................................................................................................. 17
• • 13. Measuring the flue gas temperature................................................................................. 17
• • 14. Checking the ionisation current....................................................................................... 17
• • 15. Shutting down the system................................................................................................. 18
••• 16. Opening the boiler.............................................................................................................. 19
• • 17. Opening the combustion chamber................................................................................... 20
• • 18. Cleaning the combustion chamber and heating surfaces............................................. 20
• • 19. Cleaning the burner........................................................................................................... 22
• • 20. Checking the burner door................................................................................................. 22
• • 21. Checking the burner gauze assembly.............................................................................. 23
• • 22. Checking the ignition electrodes and ionisation electrode........................................... 24
•23. Fitting the burner................................................................................................................ 24
• • 24. Closing the combustion chamber.................................................................................... 24
• • 25. Checking the gas train valves for tightness.................................................................... 25
• • 26. Checking the gas train filter element............................................................................... 26
• • 27. Checking the filter element in the gas line...................................................................... 26
••• 28. Checking the gas connections for tightness................................................................... 26
• • 29. Cleaning the condensate drain pipe and trap................................................................. 27
• • 30. Checking the condensate drain and the neutralising system (if installed).................. 28
• • 31. Closing the boiler casing................................................................................................... 28
• • 32. Checking the expansion vessel........................................................................................ 28
• • 33. Checking the water quality................................................................................................ 28
• • 34. Checking the gaskets on the flue gas side...................................................................... 28
•35. Performing final checks..................................................................................................... 29
••• 36. Checking the safety valve function
• • 37. Checking the mixer for ease of operation and leaks...................................................... 29
••• 38. Checking the thermal insulation for firm seating
Commissioning, inspection, maintenance
Steps - commissioning, inspection and maintenance
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Commissioning steps
Inspection steps
Maintenance steps Page
••• 39. Checking the flue system for unrestricted flow and tightness...................................... 30
••• 40. Checking the installation room ventilation air apertures............................................... 30
•41. Instructing the system user.............................................................................................. 30
Commissioning, inspection, maintenance
Steps - commissioning, inspection and… (cont.)
5833296

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!Please note
Unsuitable water quality can damage the boiler
body.
Only fill the boiler with water that complies with
the "Water quality requirements": See page 59
Enter the amount of fill water, water hardness and pH
value in the log on page 61.
Filling the trap with water
A B
Fig. 1
ATrap lower section
BCondensate drain hose
1. Undo lower section of trap. Fill the lower section
with water.
Danger
If the trap is not full, flue gas can escape.
Escaping flue gas can cause life threatening
carbon monoxide poisoning.
Always fill the trap with water before com-
missioning.
2. Check that the condensate can drain freely.
3. Refit lower trap section.
Commissioning, inspection, maintenance
Filling the heating system with water and venting the system
5833296

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A
B
C
D
E
F
G
H
Fig. 2
AFemale connection for control equipment: R ½
BBoiler flow: PN 6, DN 100 with sensor well for
boiler water temperature sensor
CFemale connection for pressure limiter: R ½
DSafety connection (safety valve): R 2
EBoiler return 2: PN 6, DN 100
FBoiler return 1: PN 6, DN 100
GDrain outlet: R 1¼
HCondensate drain: R ½
Check the connection for the sensor well and the mini-
mum pressure switch (low water indicator) for tight-
ness.
Commissioning, inspection, maintenance
Checking the sensor well and all connections on the heating water side for
tightness
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Check all electrical connections for firm seating. With control cables also check:
■Connection and kink-free routing
■Application and seating of retaining clips
Checking the gas type
1. Check with your gas supply utility regarding the
gas type and Wobbe index Ws (0 °C;
1013.25 mbar).
The boiler can be operated in the following Wobbe
index ranges:
■With natural gas E:
Wobbe index range 12.0 to 16.1 kWh/m3 (43.2 to
58.0 MJ/m3)
■With natural gas LL:
Wobbe index range 10.0 to 13.1 kWh/m3 (36.0 to
47.2 MJ/m3)
2. In the delivered condition, the burner is set up for
natural gas E. If required, change the gas type set-
ting to natural gas LL: See chapter "Setting the gas
type", page 12
3. Record the gas type in the report on page 62.
Commissioning, inspection, maintenance
Checking the electrical connections
5833296

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In the delivered condition, the boiler is preset for natu-
ral gas E and can be changed over to natural gas LL.
The setting can later be changed back to natural
gas E.
A
Fig. 3
AAdjusting screw
1. Turn the adjusting screw on the main volume but-
terfly of the gas train fully towards "–".
2. Turn the adjusting screw in direction "+" as detailed
in the table below:
3. Start the burner.
4. Measure the CO2 content in the flue gas and
adjust: See page 16.
Rated heating output Natural gas LL Natural gas E
800 kW 5 turns 4 turns
1000 kW 7 turns 6 turns
Commissioning the system
Danger
CO build-up as a result of incorrect burner
adjustment or flue gas system leakage can have
serious health implications.
Always carry out a CO test before and after
work on gas appliances.
■Vitotronic control unit operating instructions
and service instructions
■Neutralising system operating instructions
■Flue system installation instructions
Commissioning, inspection, maintenance
Setting the gas type
5833296

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1. Check the heating system pressure.
Permiss. operating pres-
sure
6 bar (0.6 MPa)
Minimum operating
pressure
0.5 bar (50 kPa)
Danger
If the operating pressure is too low, excess
temperatures in the flue system can cause
leaks. Escaping flue gas can cause life
threatening carbon monoxide poisoning.
Ensure the minimum operating pressure with
a minimum pressure switch.
2. For open flue operation: Check that the ventilation
facility in the installation room is open.
3. Open the gas line shut-off valves.
4. Check the static pressure. See page 15.
AA
Fig. 4
5. Check the setting at air pressure switch 1 A:
■Rated heating output 800 kW: 2 mbar (0.2 kPa)
■Rated heating output 1000 kW: 4 mbar (0.4 kPa)
6. Switch ON the mains isolator (outside the installa-
tion room).
7. Switch on the ON/OFF switch at the programming
unit of the control unit.
Vitotronic operating instructions
Note
During commissioning, the appliance may enter a
fault state due to remaining airlocks in the gas line:
"Burner fault" and are shown on the display
■Purge the gas line again.
■Reset burner:
to acknowledge the fault message
to reset the burner.
8. Check all gaskets and plugs, and retighten if nec-
essary.
Note
Recommendation: Check all connections on the
heating water side for leaks after approx.
500 hours run. See page 10.
Checking the flue gas damper
Where present: Check the motorised flue gas damper
(flue gas cascade accessory).
The flue gas damper must be closed in its zero volt
state (plug gD).
Commissioning, inspection, maintenance
Commissioning the system (cont.)
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The maximum heating output of the burner can be
reduced if required.
Programming unit on the burner control unit
Status Service
S
R
Fig. 5
Press the following buttons:
1. Press and hold S for longer than 2 s, flashes.
2. repeatedly, until "6" is shown under "Service".
3. S to confirm, "6" is shown under "Status" and "1" is
shown under "Service".
4. S to confirm, "1" is shown under "Status". The cur-
rent value for the maximum heating output in % is
shown under "Service".
5. Use or to select the required maximum heating
output.
6. S to confirm. If adopted successfully, "1" is shown
under "Service"; if it failed, "0" will appear.
7. S to change to the operating display.
8. R, the system will be restarted.
Checking the static pressure and supply pressure
A
Fig. 6
ATest connector
Commissioning, inspection, maintenance
Reducing the maximum heating output (if required)
5833296

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Static pressure
1. Close the gas shut-off valve.
2. Undo the screw in test connector A. Do not
remove the screw.
3. Connect the pressure tester at test connector A.
4. Open the gas shut-off valve.
5. Measure the static pressure: Max. 100 mbar
(10 kPa).
Note
The max. static pressure corresponds to the max.
permissible gas pressure at the burner to allow for
safe commissioning of the appliance.
6. Record the actual value in the report.
Supply pressure
1. Activate emissions test mode.
Vitotronic control unit operating instructions
2. Measure the supply pressure (flow pressure) at
rated heating output.
Natural gas E/LL
■Set value: 17 to 25 mbar (1.7 to 2.5 kPa)
■Nominal supply pressure: 20 mbar (2 kPa)
Note
■The nominal supply pressure can differ from
these values subject to region; see type plate of
the burner.
■The gas pressure switch on the gas train is set to
15 mbar (1.5 kPa).
i.e. the burner cannot be operated at a gas sup-
ply pressure below 15 mbar (1.5 kPa).
Note
Use a suitable measuring device with a resolution
of at least 0.1 mbar (0.01 kPa) to check the supply
pressure.
3. Record the actual value in the report.
4. Switch off the ON/OFF switch at the programming
unit of the Vitotronic control unit.
5. Close the gas shut-off valve.
6. Remove pressure gauge. Close test connector A
with the screw.
7. Open the gas shut-off valve. Start up the appli-
ance. Check gas tightness at test connector A.
Danger
Gas escaping from the test connector leads
to a risk of explosion.
Check for gas tightness.
Supply pressure
(flow pressure) nat-
ural gas E and LL
Measure
< 15 mbar
< 1.5 kPa
Do not make any adjustments.
Notify the gas supply utility.
15 to 17 mbar
1.5 to 1.7 kPa
Please note: The boiler may only be operated temporarily with this setting (emergency
mode).
Notify the gas supply utility.
Commissioning, inspection, maintenance
Checking the static pressure and supply pressure (cont.)
5833296

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Supply pressure
(flow pressure) nat-
ural gas E and LL
Measure
17 to 25 mbar
1.7 to 2.5 kPa
Start the boiler.
> 25 mbar
> 2.5 kPa
Install a separate gas pressure governor with zero off upstream of the boiler system. Set
it to 20 mbar (2 kPa) (nominal supply pressure).
Note
The nominal supply pressure must be set subject to regional conditions, see type plate of
the burner.
Measuring the CO2 content
Programming unit on the burner control unit
Status Service
S
R
Fig. 7
Adjusting screws on the gas train
AB
Fig. 8
01. Check control cables:
■Connection and kink-free routing
■Fixing and firm seating of the connecting points
02. Open the gas shut-off valve.
03. Activate emissions test mode.
Vitotronic control unit operating instructions
04. On the burner control unit, hold down S+ simulta-
neously for longer than 2 s.
■"P" is displayed under "Status" (controlled stop).
■The current modulation level in % is shown
under "Service".
05. To measure the CO2, set the upper and lower
heating output in turn:
■Upper heating output:
Press until "100" (≙ 100 %) is shown under
"Service".
■Lower heating output:
Press until "0" (≙ 0 %) is shown under "Serv-
ice".
06. Measure the CO2 content at the flue pipe.
For permissible CO2 content, see the table.
Note
At the lower heating output, the CO2 content must
always be lower than at the upper heating output.
Commissioning, inspection, maintenance
Checking the static pressure and supply pressure (cont.)
5833296

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07. If the CO2 content lies outside the specified range:
■Upper heating output:
Turn adjusting screw A in very small incre-
ments until the CO2 content is within the speci-
fied range.
■Lower heating output:
Turn adjusting screw B in small increments
until the CO2 content is within the specified
range.
Rotational direction of adjusting screws A and
B:
■Direction "–": CO2 content falls.
■Direction "+": CO2 content rises.
08. Check the CO2 content at the upper and lower
heating output again.
If required, set the CO2 content for the upper and
lower heating output again.
09. Enter the actual values into the report.
10. On the burner control unit, press and hold S and
simultaneously for longer than 2 s. Burner
switches to operating mode.
Permissible CO2 content
Gas type Heating output CO2 content, dry
Natural gas E
Wobbe index Ws 12.0 to 16.1 kWh/m3
(0 °C; 1013.25 mbar)
Upper heating output (100 %) 8.9 ±0.1 %
Lower heating output (0 %) 7.9 ±0.1 %
Natural gas LL
Wobbe index Ws 10.0 to 13.1 kWh/m3
(0 °C; 1013.25 mbar)
Upper heating output (100 %) 8.8 ±0.1 %
Lower heating output (0 %) 7.8 ±0.1 %
Measuring the CO content
Enter the actual value in the service report.
Measuring the flue gas temperature
Enter the actual value in the service report.
Checking the ionisation current
Note
The ionisation current can only be called up via the
programming unit of the burner control unit. It is not
possible to measure it with Testomatik-Gas or a multi-
meter.
Programming unit on the burner control unit
Status Service
S
R
Fig. 9
Press the following buttons:
01. Press and hold S for longer than 2 s, flashes.
02. repeatedly, until "5" is shown under "Service".
03. S to confirm, "5" is shown under "Status".
04. repeatedly, until "3" is shown under "Service".
05. S to confirm, "3" is shown under "Status". During
operation, the actual ionisation current is shown
under "Service" (e.g. 30 ≙ 3.0 µA).
06. Activate emissions test mode.
Vitotronic control unit operating instructions
Commissioning, inspection, maintenance
Measuring the CO2 content (cont.)
5833296

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07. Read the ionisation current.
08. Enter the actual value in the service report.
09. Press and hold S for longer than 2 s, flashes.
10. repeatedly, until "5" is shown under "Service".
11. S to confirm, "5" is shown under "Status".
12. repeatedly, until "0" is shown under "Service".
13. S to change to the operating display.
Shutting down the system
1. Isolate the system from the power supply, e.g. by
removing the separate fuse or by means of a
mains isolator, and check that it is no longer live.
Safeguard the system against reconnection.
Danger
An electric shock can be life threatening.
Before opening the boiler, disconnect it from
the mains voltage, e.g. at the fuse or mains
isolator.
2. Close the gas shut-off valve.
Commissioning, inspection, maintenance
Checking the ionisation current (cont.)
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1.
2.
4.
3.
2x
Fig. 10
Commissioning, inspection, maintenance
Opening the boiler
5833296

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1.
2.
8.3.
4. 6x
5.
Fig. 11
Danger
Serious injuries can result from the burner door
falling shut.
Secure the burner door against unintentional
closure.
!Please note
Scratches inside the combustion chamber can
lead to corrosion damage.
Never place tools or other objects inside the
combustion chamber.
Cleaning the combustion chamber and heating surfaces
!Please note
Scratches inside the combustion chamber or on
components that come into contact with flue gas
can lead to corrosion damage.
■Only clean with synthetic brushes, never use
wire brushes or sharp objects.
■Never place tools or other objects inside the
combustion chamber.
To clean, thoroughly flush the heating surfaces with a
jet of water.
Commissioning, inspection, maintenance
Opening the combustion chamber
5833296