Viessmann Vitocrossal CRU 800 Operating instructions

Service instructions
for contractors
VIESMANN
Vitocrossal
Type CRU, 800 and 1000
Gas condensing boiler
For open flue and room sealed operation
Permissible operating pressure 6 bar
VITOCROSSAL
6151139 GB 7/2020 Please keep safe.

2
Please follow these safety instruc-
tions 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 environmen-
tal pollution.
Note
Details identified by the word "Note"
contain additional information.
Target group
These instructions are exclusively inten-
ded for qualified 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 per-
son 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
■Relevant country-specific safety regu-
lations
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 safe-
guard it against unintentional reopen-
ing.
■Isolate the system from the power sup-
ply, 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 recon-
nection.
■Wear suitable personal protective
equipment when carrying out any work.
Safety instructions
Safety instructions
6151139

3
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 pipe-
work.
!Please note
Electronic assemblies can be dam-
aged by electrostatic discharge.
Prior to commencing work, touch
earthed objects such as heating or
water pipes to discharge static
loads.
Repair work
!Please note
Repairing components that fulfil a
safety function can compromise the
safe operation of the system.
Replace faulty components only
with genuine Viessmann spare
parts.
Auxiliary components, spare and
wearing parts
!Please note
Spare and wearing parts that have
not been tested together with the
system can compromise its func-
tion. Installing non-authorised com-
ponents and making non-approved
modifications or conversions can
compromise safety and may invalid-
ate our warranty.
For replacements, use only original
spare parts supplied or approved by
Viessmann.
Safety instructions
Safety instructions (cont.)
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4
Safety instructions for operating the system
If you smell gas
Danger
Escaping gas can lead to explo-
sions which may result in serious
injury.
■Do not smoke. Prevent naked
flames and sparks. Never switch
lights or electrical appliances 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 sup-
ply 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 spread-
ing.
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 condensate or other
external causes.
Ensure an adequate supply of combus-
tion air.
Inform system users that subsequent
modifications to the building characteris-
tics are not permissible (e.g. cable/pipe-
work routing, cladding or partitions).
Danger
Leaking or blocked flue systems, or
an inadequate supply of combus-
tion 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-seala-
ble.
Extractors
Operating appliances that exhaust air to
the outside (extractor hoods, extractors,
air conditioning units, etc.) can create
negative pressure. If the boiler is oper-
ated at the same time, this can lead to a
reverse flow of flue gas.
Safety instructions
Safety instructions (cont.)
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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 suita-
ble steps to ensure an adequate
supply of combustion air.
Safety instructions
Safety instructions (cont.)
6151139

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1. Information Symbols ................................................................................................. 7
Intended use .......................................................................................... 7
Product information ................................................................................ 8
■Burner ................................................................................................. 8
■System examples ............................................................................... 8
■Spare parts lists .................................................................................. 8
2. Commissioning, inspec-
tion, maintenance
Steps - commissioning, inspection and maintenance ............................ 9
3. Reports ................................................................................................................ 25
4. Specification ................................................................................................................ 27
5. Final decommissioning Final decommissioning and disposal ..................................................... 29
6. Certificates Declaration of conformity ....................................................................... 30
Manufacturer's certificate according to the 1st BImSchV [Germany] .... 30
7. Keyword index ................................................................................................................ 31
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
6151139
Information

8
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.
Burner
Information on installation, commissioning,
inspection and maintenance of the burner
■"MatriX-Disk burner" installation instructions
■"MatriX-Disk burner" service instructions
System examples
Available system examples: See www.viessmann-
schemes.com.
Spare parts lists
Information about spare parts can be found at
www.viessmann.com/etapp or in the Viessmann
spare part app.
Information
Product information
6151139
Information

9
Commissioning steps
Inspection steps
Maintenance steps Page
••• 1. Burner inspection and maintenance................................................................................ 10
•2. Checking the electrical connections................................................................................ 10
•3. Filling the heating system with water and venting the system...................................... 10
•4. Filling the trap with water.................................................................................................. 11
• • 5. Checking the sensor well and all connections on the heating water side for
tightness............................................................................................................................. 12
•6. Checking high limit safety cut-out settings..................................................................... 13
•7. Checking the gas type....................................................................................................... 13
•8. Setting the gas type........................................................................................................... 13
••• 9. Commissioning the system............................................................................................... 13
••• 10. Checking the flue gas damper.......................................................................................... 15
•11. Reducing the maximum heating output (if required)...................................................... 15
• • 12. Measuring the flue gas temperature................................................................................. 15
• • 13. Shutting down the system................................................................................................. 15
••• 14. Opening the boiler.............................................................................................................. 16
• • 15. Opening the combustion chamber................................................................................... 17
• • 16. Cleaning the combustion chamber and heating surfaces............................................. 18
• • 17. Closing the combustion chamber.................................................................................... 18
• • 18. Checking the filter element in the gas line...................................................................... 18
••• 19. Checking the gas connections for tightness................................................................... 18
• • 20. Cleaning the condensate drain pipe and trap................................................................. 19
• • 21. Checking the condensate drain and the neutralising system (if installed).................. 20
• • 22. Closing the boiler casing................................................................................................... 20
• • 23. Checking the expansion vessel........................................................................................ 20
• • 24. Checking the water quality................................................................................................ 20
• • 25. Checking the gaskets on the flue gas side...................................................................... 20
•26. Performing final checks..................................................................................................... 21
••• 27. Checking the safety valve function
• • 28. Check mixer (if installed) for ease of movement and leak-tightness............................ 21
••• 29. Checking the thermal insulation for firm seating
••• 30. Checking the flue system for unrestricted flow and tightness...................................... 22
••• 31. Checking the installation room ventilation air apertures............................................... 22
•32. Instructing the system user.............................................................................................. 22
Commissioning, inspection, maintenance
Steps - commissioning, inspection and maintenance
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Steps applicable to the MatriX-Disk burner are descri-
bed in separate instructions.
"MatriX-Disk burner" service instructions
Checking the electrical connections
Check all electrical connection for firm seating.
Filling the heating system with water and venting the system
!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 23
Enter the amount of fill water, the water hardness and
the pH value in the report on page 25.
Commissioning, inspection, maintenance
Burner inspection and maintenance
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A B
Fig. 1
ATrap lower section
BCondensate drain hose
1. Fill the trap with water. To do this, pour water into
the boiler via the combustion chamber or the
inspection port of the flue system.
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 from
the condensate drain hose. Check the trap for
leaks.
3. If trap is leaking, unscrew the lower part. Check the
gasket and replace if necessary.
Commissioning, inspection, maintenance
Filling the trap with water
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Note
For a clearer overview of the connections, the boiler is
shown without cladding.
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
Commissioning, inspection, maintenance
Checking the sensor well and all connections on the heating water side for
tightness
6151139

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Check the connection for the sensor well and the mini-
mum pressure switch (low water indicator) for tight-
ness.
Checking high limit safety cut-out settings
The high limit safety cut-out must not be set higher
than 110 °C. If necessary, set to max. 110 °C.
Installation and service instructions for the Vito-
tronic control unit
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 11. 13
3. Record the gas type in the report on page 26.
Setting the gas type
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.
"MatriX-Disk burner" service instructions
Commissioning the system
■Operating instructions and service instructions
for the Vitotronic control unit
■"MatriX-Disk burner" service instructions
■Neutralising system operating instructions
■Flue system installation instructions
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.
Commissioning, inspection, maintenance
Checking the sensor well and all connections on… (cont.)
6151139

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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. With open flue operation: Check that the ventilation
facility in the installation room is open and suffi-
ciently large.
3. Open the gas line shut-off valves.
4. Check the static and the supply pressure.
"MatriX-Disk burner" service instructions
A
Fig. 3
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 control unit 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 12.
Commissioning, inspection, maintenance
Commissioning the system (cont.)
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If installed: Check motorised flue gas damper for cas-
cade operation.
The flue gas damper must be closed in its zero volt
state (plug gD).
Note
The code for the flue gas damper must be set at the
burner control unit.
"MatriX-Disk burner" service instructions
Reducing the maximum heating output (if required)
"MatriX-Disk burner" service instructions
Measuring the flue gas temperature
Enter the actual value in the service report.
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 flue gas damper
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1.
2.
4.
3.
2x
Fig. 4
Commissioning, inspection, maintenance
Opening the boiler
6151139

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1.
2.
8.3.
4. 6x
5.
Fig. 5
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.
Note
If the burner is operated in room sealed mode, remove
the room sealed set.
Commissioning, inspection, maintenance
Opening the combustion chamber
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!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.
For stubborn residues, surface stains or soot deposits,
cleaning agents can be used under the following con-
ditions:
■Only use solvent-free cleaning agents. Ensure that
no cleaning agent gets between the boiler body and
the thermal insulation.
■Remove soot deposits with an alkaline cleaning
agent with surfactant additive (e.g. Fauch 600).
■Remove coatings and surface discolouration (yellow-
brown) with slightly acidic, chloride-free cleaning
agents based on phosphoric acid (e.g. Antox 75 E).
■Remove loose deposits from the boiler; thoroughly
flush the heating surfaces and the flue gas collector
with a water jet.
Cleaning agent manufacturer's instructions
Recommendation:
"Fauch 600" and "Antox 75 E"
Manufacturer:
Hebro Chemie GmbH
Rostocker Strasse 40
D-41199 Mönchengladbach
Closing the combustion chamber
Close the combustion chamber in reverse order: See
Fig. 5, page 17
Tighten the burner door screws diagonally to a torque
of 30 Nm.
Danger
Leaks in the burner door can result in poisoning
through escaping flue gas.
Check the burner door for flue gas tightness,
e.g. with inspection mirror, dew point indicator,
gas sensor or thermal image camera.
In the event of leaks: Tighten the burner door
screws diagonally to a torque of 40 Nm.
Check the flue gas tightness again.
Checking the filter element in the gas line
If a filter element is fitted in the gas line, check the filter
element and clean or replace if necessary.
Manufacturer's instructions for filter element
Checking the gas connections for tightness
Danger
Escaping gas leads to a risk of explosion.
Check all gas equipment for tightness.
1. Insert new gaskets in all gas fittings that have been
opened and retighten them.
2. Open the gas shut-off valve.
3. Check the inlet joints of the gas train for tightness.
4. Commissioning the system (see page 13).
Commissioning, inspection, maintenance
Cleaning the combustion chamber and heating surfaces
6151139

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5. Check for tightness:
■Outlet joints of the gas train
■Joint between the fan and the fitting
■Joint between the fan and the supply air collector
Service instructions for the "MatriX-Disk
burner"
!Please note
The use of leak detection spray can result in
faulty operation.
Leak detection spray must not come into contact
with electrical contacts.
Note
Only use suitable and approved leak detection agents
(EN 14291) and devices for the tightness test. Leak
detection agents with unsuitable constituents (e.g.
nitrides, sulphides) can cause material damage.
Remove residues of the leak detection agent after test-
ing.
Cleaning the condensate drain pipe and trap
Note
Clean the condensate drain pipe and trap at least once
a year.
A B
Fig. 6
1. Disconnect neutralising system condensate drain
hose B from trap A.
2. Connect the cleaning hose to the trap and route it
to the drainage system.
3. Clean the inside of the condensate drain pipe
(hose, pipes) and trap A.
4. Fill the lower section of trap A with water and
secure.
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.
5. Reconnect the condensate drain hose for the neu-
tralising system to the trap. Route the condensate
drain hose without kinks and with a constant fall.
Commissioning, inspection, maintenance
Checking the gas connections for tightness (cont.)
6151139

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1. Fill the combustion chamber with water.
Note
The water must flow from the condensate drain
pipe without backing up.
If necessary, clean the condensate drain pipe
again.
2. Check the function of the neutralising system.
Neutralising system operating instructions
3. If necessary, clean the neutralising system in
accordance with the manufacturer's instructions.
Neutralising system operating instructions
Note
Neutralising medium from Viessmann Werke
GmbH & Co. KG, part no. 9521702.
4. Check entire condensate drain pipe for leaks.
Closing the boiler casing
Close the boiler again in reverse order to Fig. 4 on
page 16.
Checking the expansion vessel
Note
Observe the manufacturer's instructions for the expan-
sion vessel.
Carry out this test on a cold system.
1. Drain the system until the pressure gauge indi-
cates "0" or close the cap valve on the expansion
vessel and reduce the pressure in the expansion
vessel.
2. If the expansion vessel pre-charge pressure is
lower than the static system pressure, top up with
nitrogen. Top up with nitrogen until the pre-charge
pressure is 0.1 to 0.2 bar (10 to 20 kPa) higher.
3. Top up with water. The charge pressure of the
cooled system must be 0.1 to 0.2 bar (10 to
20 kPa) higher than the pre-charge pressure of the
expansion vessel.
Permiss. operating pressure: 6 bar/0.6 MPa
Checking the water quality
Enter the amount of top-up water, the total hardness
and the pH value in the tables on page 25.
For water quality requirements: See page 23.
Checking the gaskets on the flue gas side
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.
Commissioning, inspection, maintenance
Checking the condensate drain and the neutralising system (if installed)
6151139