Viessmann VITOCROSSAL 300 Operating instructions

Service instructions
for contractors
VIESMANN
Vitocrossal 300
Type CR3B, 787 to 1400 kW
Gas condensing boiler
VITOCROSSAL 300
5836858 GB 9/2020 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
5836858

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.)
5836858

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.)
5836858

5
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.)
5836858

6
1. Information Key to date of manufacture .................................................................... 7
Symbols ................................................................................................. 7
Intended use .......................................................................................... 8
Product information ................................................................................ 8
■System examples ............................................................................... 8
■Spare parts lists .................................................................................. 8
2. Commissioning, inspec-
tion, maintenance
Steps - commissioning, inspection and maintenance ............................ 9
3. Water quality Water quality requirements .................................................................... 22
■Prevention of damage due to scaling ................................................. 22
■Prevention of damage due to corrosion on the water side ................. 23
4. Commissioning/service
reports
Water quality .......................................................................................... 24
Maintenance/service .............................................................................. 24
5. Specification ................................................................................................................ 26
6. Final decommissioning
and disposal
................................................................................................................ 27
7. Certificates EU Declaration of Conformity ................................................................ 28
Manufacturer's certificate ....................................................................... 28
■Vitocrossal 300, type CR3B ................................................................ 28
8. Keyword index ................................................................................................................ 29
Index
Index
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7
1 2 43 5 6 7
X X 0 1 2 5 5
Day
Year
Week
Fig. 1
Digits 1 and 2Internal Viessmann information
Digits 3 and 70 and 5 = calendar week 05 = 5th calendar week
Digits 4 and 61 and 5 = year 2015
Digit 52 = 2nd day of the working week
(Monday = 1, Tuesday = 2, etc.)
Example 0501255 corresponds to date of manufacture: 27 January 2015
Symbols
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
Information
Key to date of manufacture
5836858
Information

8
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.
Product information
Vitocrossal 300, type CR3B
■Fuel: Natural gas E, natural gas LL and LPG
■Rated heating output 787 kW and 1400 kW
■Permissible operating pressure 6 bar (0.6 MPa)
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
Intended use
5836858
Information

9
Commissioning steps
Inspection steps
Maintenance steps Page
•1. Checking the high limit safety cut-out setting................................................................ 10
•2. Filling the heating system with water and venting......................................................... 10
••• 3. Filling the trap with water.................................................................................................. 11
•4. Fully opening and locking the butterfly valve in the flue outlet (if installed)............... 11
••• 5. Commissioning the system............................................................................................... 12
•6. Minimising pulsation noise............................................................................................... 13
• • 7. Shutting down the system................................................................................................. 13
• • 8. Opening the boiler door..................................................................................................... 13
• • 9. Separating the neutralising system from the heat exchanger module and
connecting the drain hose................................................................................................. 14
• • 10. Cleaning the combustion chamber and heating surfaces............................................. 14
• • 11. Checking the boiler door/burner gaskets and thermal insulation sections................. 14
••• 12. Checking all connections and the sensor well on the heating water side for
tightness............................................................................................................................. 16
• • 13. Checking the function of the safety equipment.............................................................. 18
••• 14. Checking the pressure switch function........................................................................... 18
••• 15. Checking the temperature controller setting if a building management system is
used (DCC system)............................................................................................................ 18
••• 16. Expansion vessel and system pressure.......................................................................... 18
•17. Cleaning the sight glass in the boiler door...................................................................... 19
• • 18. Closing the boiler door...................................................................................................... 19
•19. Checking the thermal insulation....................................................................................... 19
• • 20. Checking the water quality................................................................................................ 20
• • 21. Cleaning and reconnecting the condensate drain system............................................. 20
•22. Checking the installation room vent
• • 23. Adjusting the burner.......................................................................................................... 20
• • 24. Checking the flue gas side tightness............................................................................... 21
•25. Checking the flue system for leaks
•26. Instructing the system user.............................................................................................. 21
•27. Operating and service documents................................................................................... 21
Commissioning, inspection, maintenance
Steps - commissioning, inspection and maintenance
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The high limit safety cut-out must not be set higher
than 110 °C. If required, set it to a maximum of 110 °C.
Control unit installation and service instructions
Filling the heating system with water and venting
Record the volume filled, water hardness and pH value
on page 24.
Permissible boiler operating pressure: 6 bar (0.6 MPa). !Please note
Unsuitable water quality can result in damage to
the boiler body and the heating system.
Fill the heating system with water and operate it
in accordance with VDI Guideline 2035. The
total of alkaline earths must not exceed
0.02 mol/m3 (total hardness 0.11 °dH).
Observe the "Water quality requirements" on
page 22.
Commissioning, inspection, maintenance
Checking the high limit safety cut-out setting
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A B
Fig. 2
ALower part of trap
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.
Fully opening and locking the butterfly valve in the flue outlet (if
installed)
Note
Some burners require a butterfly valve (accessories) to
regulate the back pressure.
The butterfly valve must be in the horizontal position.
Commissioning, inspection, maintenance
Filling the trap with water
5836858

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A B C
Fig. 3
AScrew for locking the adjusting lever
BAdjusting lever
CButterfly valve
Commissioning the system
Operating instructions for control unit, burner
and neutralising system, service instructions for
control unit, and burner manufacturer's docu-
mentation
1. Check the heating system pressure.
Permissible boiler operating pressure: 6 bar
(0.6 MPa)
2. For open flue operation: Check that the vent in the
installation room is open. The cross-section of the
vent must meet the requirements of the FeuVo
[check local fire regulations].
3. Check the gas supply pressure.
4. Open the gas line shut-off valves.
5. Start the system in this order:
1. ON/OFF switch (heating system emergency
switch)
2. Switch on the boiler control unit and heating cir-
cuit control unit.
Burner manufacturer's operating instructions
6. Check the function of the neutralising system and
the hydraulic seal in the trap.
Neutralising system operating instructions
7. Check all gaskets and plugs, and retighten if nec-
essary.
Note
We recommend checking all connections on the
heating water side for leaks approx. every 500
hours run. See page 16.
8. Check the boiler door a few days after commis-
sioning and retighten the screws.
9. Tighten the screws at the connecting points with
the following torque:
Boiler door 20 Nm
Flange connections 150 Nm
Module connection 60 Nm
Flue gas collector 7 Nm
Commissioning, inspection, maintenance
Fully opening and locking the butterfly valve… (cont.)
5836858

13
Danger
For safe operation, a minimum operating pres-
sure of 0.5 bar (50 kPa) is essential.
A minimum pressure switch can be used for this
purpose. See EN 12828.
Minimising pulsation noise
Pressure-tight flue systems can generate pulsation
noise regardless of the make of boiler, burner or flue
system. This also applies to negative pressure opera-
tion. Acoustic resonance may occur if the optional but-
terfly valve in the flue outlet is twisted.
Note
Observe the burner manufacturer's instructions.
1. Undo M 5 screw A on lever B of the damper
lock. See Fig. 3
2. Adjust the lever until no further pulsation noise
occurs. The lever indicates the position of butterfly
valve C. Check the emissions values if necessary.
3. Tighten M 5 screw A on lever B of the damper
lock.
4. Adjust the burner.
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.
Opening the boiler door
Danger
When working with high temperature insulating
materials that contain zirconium or aluminium
silicate ceramic fibres, fibre dust may develop.
This fibre dust can be harmful to health.
Only trained personnel may adjust or replace
the insulation. Wear suitable protective clothing,
especially breathing equipment and safety gog-
gles.
1. Remove the gas supply pipe.
2. Undo 4 screws on the boiler door. Open the boiler
door.
!Please note
Scratches inside the combustion chamber can
lead to corrosion.
Never place tools or other objects inside the
combustion chamber.
Commissioning, inspection, maintenance
Commissioning the system (cont.)
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14
D
C
B
A
Fig. 4
1. Separate hose or pipework A to the neutralising
system from siphon B.
2. Undo siphon B from condensate drain C.
3. Clean all components on the inside with plastic
brush.
4. Connect drain hose D to condensate drain C and
route it to a drainage system.
Cleaning the combustion chamber and heating surfaces
!Please note
Contact with unalloyed iron and scratches on
parts in contact with flue gases can lead to cor-
rosion.
Only use plastic brushes, not wire brushes or
sharp objects.
1. Clean the combustion chamber and heating surfa-
ces.
■For normal cleaning, flush the heating surfaces
thoroughly with a jet of water.
■You may use cleaning agents if you notice stub-
born residues, surface discolouration or soot
deposits.
For this, observe the following:
–Only use solvent-free cleaning agents. Ensure
that no cleaning agent gets between the boiler
shell and the thermal insulation.
–Remove soot deposits with an alkaline clean-
ing agent with surfactant additive (e.g. Fauch
condensing boiler cleaner or Sotin 300).
–Remove coatings and surface discolouration
(yellow-brown) with slightly acidic, chloride-free
cleaning agents based on phosphoric acid (e.g.
Antox 75 E).
2. Remove loosened deposits from the boiler. Thor-
oughly flush heating surfaces and the flue gas col-
lector with a jet of water.
Danger
Loose residues and residual cleaning agents
can lead to injury.
Wear goggles, protective gloves and protective
clothing.
Cleaning agent manufacturer's details
Note
"Fauch" and "Antox 75 E"
Manufacturer: Hebro Chemie GmbH, Mönchenglad-
bach
www.hebro-chemie.de
"Sotin 300"
Manufacturer: Sotin Chemische und technische Pro-
dukte GmbH & Co., Bad Kreuznach
www.sotin.de
Checking the boiler door/burner gaskets and thermal insulation sections
1. Check gaskets and packing cord in the boiler door
for damage.
2. Check thermal insulation components on the boiler
door for damage.
3. Replace any damaged parts.
Commissioning, inspection, maintenance
Separating the neutralising system from the heat exchanger module and
connecting the drain hose
5836858

15
A
D
B
E
C
Ø = Ø B -10
Fig. 5
ABoiler door
BFlame tube
CThermal insulation mat
DBurner plate
EThermal insulation block
Check the thermal insulation mat at the flame tube.
The blue side of the thermal insulation mat has to face
the combustion chamber. It must be in close contact
with the flame tube.
Commissioning, inspection, maintenance
Checking the boiler door/burner gaskets and… (cont.)
5836858

16
Removing the casing panels
1.
2.
4.
3.
5. 3x
6x
Fig. 6
6. Open the thermal insulation jacket if necessary. Danger
There is a risk of injury when working on pres-
surised components.
Only open the connections on the heating water
side after the boiler has been depressurised.
If draining with a suction pump, only drain the
boiler with the air vent valve open.
Commissioning, inspection, maintenance
Checking all connections and the sensor well on the heating water side for
tightness
5836858

17
Checking gaskets
A B CD E F
G
HK
Fig. 7
ABoiler return 2
BBoiler return 1
CSafety connection (safety valve)
DSleeve for pressure limiter
EBoiler flow
FSleeve for control equipment
GDrain outlet
HCondensate drain
KConnecting flanges for heat exchanger/combustion
chamber module
Note
To provide a better overview, the boiler is shown here
without its insulation and casing.
Note
In full load operation, the gaskets can be checked with
an inspection mirror. If required, remove the thermal
insulation sections.
Commissioning, inspection, maintenance
Checking all connections and the sensor well on… (cont.)
5836858

18
Check safety valves, water level and pressure limiter in
accordance with manufacturer's details.
Checking the pressure switch function
Installation instructions in the "pressure switch
set"
Checking the temperature controller setting if a building management system
is used (DCC system)
!Please note
Shutting down from full load can result in high
material stress and material damage.
If a system with a higher ranking building man-
agement system takes over the temperature
control of the boiler, adjust the settings at the
temperature controller TR. Set the electronic
temperature controller to at least 10 K below the
mechanical temperature controller.
Expansion vessel and system pressure
Note
Observe the manufacturer's instructions for the dia-
phragm expansion vessel (MAG).
Check when system is cold.
1. Drain the system or close the cap valve on the
expansion vessel and reduce the pressure until the
pressure gauge indicates "0".
Note
The pre-charge pressure of the expansion vessel
(p0) is made up of the static system pressure (pSt)
(= static head) and a supplement (p0 = pSt + sup-
plement).
The supplement depends on the high limit safety
cut-out setting.
Supplement
100 °C: 0.2 bar (20 kPa)
110 °C: 0.7 bar (70 kPa)
2. If the pre-charge pressure of the expansion vessel
is lower than the value calculated using the for-
mula, top up with sufficient nitrogen to achieve this
value.
3. Refill with water until the charge pressure is 0.2
(20 kPa) higher than the pre-charge pressure of
the expansion vessel when the system is cold.
4. Mark this value on the pressure gauge as the mini-
mum charge pressure.
Commissioning, inspection, maintenance
Checking the function of the safety equipment
5836858

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Pump controlled pressure maintaining systems
Note
In heating systems with automatic pressure maintain-
ing equipment or deaeration systems (operating
according to the pressure reduction method for deaer-
ation), we recommend installing an expansion vessel
(DEV) for individual boiler protection.
The expansion vessel must be able to absorb the
expansion volume of the heating water in the boiler.
Minimum size 35 l
The expansion vessel reduces the frequency and
severity of pressure fluctuations. The expansion vessel
improves the runtime of the pressure maintaining
pump and therefore increases the operational reliability
and service life of the system components. Failure to
observe these recommendations may result in
damage to the boiler or to other system compo-
nents.
Check the pressure maintaining system in line with the
manufacturer's instructions. Limit pressure fluctuations
to the lowest possible differential. Cyclical pressure
fluctuations and more significant pressure differentials
point towards a system fault. Remedy such faults
immediately to prevent damage to other components
in the heating system.
Cleaning the sight glass in the boiler door
BA
Fig. 8
Check gaskets A and hose connection B for leaks.
Danger
Leaks can result in a risk of poisoning through
escaping flue gas.
Check gaskets carefully.
Closing the boiler door
1. Tighten the screws on the boiler door evenly and
diagonally. Torque: 20 Nm
2. Fit the gas supply pipe and check for leaks.
Checking the thermal insulation
Check the thermal insulation fit and realign if required.
Commissioning, inspection, maintenance
Expansion vessel and system pressure (cont.)
5836858

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Enter the amount of top-up water and the total hard-
ness of the feed and boiler water into the table in the
appendix on page 24.
For water quality requirements, see page 22.
The total hardness of the feed and top-up water must
not exceed the standard values specified by VDI 2035
(see page 22).
The pH value should be between 8.2 and 9.5.
Cleaning and reconnecting the condensate drain system
The condensate drain, trap, neutralising system and all
hoses and pipes between them are part of the conden-
sate drain system.
Note
Clean the inside of the condensate drain pipe at least
once a year.
A
B
C
E
D
Fig. 9
1. Disconnect drain or cleaning hose C.
2. Clean condensate drain A again from the inside
using a plastic brush.
3. Undo and flush lower part E of siphon B. Clean
the inlet connector of siphon B with a brush.
4. Secure siphon B on condensate drain A and
seal in if required.
5. Fill lower section E of the siphon with water and
refit.
Note
If the siphon is not filled with water, flue gas can
escape.
6. Clean the inside of the pipes in the condensate
drain system and the neutralising system.
Neutralising system operating instructions
7. Connect the inlet of the neutralising system to trap
B using pipe D (and seal in if necessary). Ensure
the condensate drain is routed with a fall so that it
can drain freely.
Checking the installation room vent
Adjusting the burner
Observe the burner manufacturer's instructions.
Commissioning, inspection, maintenance
Checking the water quality
5836858