Viessmann B0KA Quick guide

Installation and service instructions
for contractors
VIESMANN
Vitodens 050-W
Type B0KA, BPKA, 3.2 to 25 kW
Type B0KA-M (for multiple connection), 7.0 to 25 kW
Wall mounted gas condensing boiler
Natural gas version
Gas Council No.
■B0KA: 47-819-55, 47-819-57
■B0KA-M: 47-819-56
VITODENS 050-W
6173886 GB 6/2021 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
6173886

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.)
6173886

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.)
6173886

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.)
6173886

6
1. Information Disposal of packaging ............................................................................ 8
Gas Council No. ..................................................................................... 8
Symbols ................................................................................................. 8
Intended use .......................................................................................... 9
Product information ................................................................................ 9
■Type plate ........................................................................................... 9
System examples .................................................................................. 10
Spare parts lists ..................................................................................... 10
2. Preparing for installation ................................................................................................................ 11
3. Installation sequence Removing the boiler from the packaging ............................................... 14
Mounting the boiler and making connections ........................................ 15
■Removing the front panel ................................................................... 15
■Mounting the boiler on the pre-plumbing jig or mounting frame ......... 15
■Fitting the boiler to the wall mounting bracket .................................... 17
■Connections on the heating water and DHW sides ............................ 19
Condensate connection ......................................................................... 20
■Filling the trap with water .................................................................... 20
Flue gas connection ............................................................................... 21
Gas connection ...................................................................................... 22
Electrical connections ............................................................................ 23
■Opening the wiring chamber ............................................................... 23
■Layout of the electrical connections ................................................... 23
■On-site connections on the HBMU heat management unit ................ 24
■Outside temperature sensor ............................................................... 24
■Connecting the cylinder temperature sensor ...................................... 24
■Power supply fÖ ................................................................................. 25
■Routing connecting cables/leads ........................................................ 25
WiFi operational reliability and system requirements ............................ 26
■Wireless signal range of WiFi connection ........................................... 26
■Angle of penetration ........................................................................... 26
Closing the wiring chamber ................................................................... 27
Fitting the front panel ............................................................................. 28
4. Commissioning, inspec-
tion, maintenance
Steps - commissioning, inspection and maintenance ............................ 29
5. System configuration
(parameters)
Calling up parameters ............................................................................ 51
Parameters ............................................................................................ 51
■Energy saving functions (setting only via software tool) ..................... 52
6. Diagnosis and service
checks
Service menu ......................................................................................... 54
■Calling up the service menu ............................................................... 54
■Exiting the service menu .................................................................... 54
Diagnosis ............................................................................................... 55
■Checking operating data ..................................................................... 55
7. Troubleshooting Fault display on the programming unit ................................................... 56
Overview of electronics modules ........................................................... 57
Fault messages ..................................................................................... 57
Repairs .................................................................................................. 71
■Shutting down the boiler ..................................................................... 72
■Removing the boiler from the pre-plumbing jig or mounting frame ..... 72
■Checking the temperature sensors ..................................................... 73
■Information on replacing the HBMU heat management unit ............... 75
■Replacing the power cable ................................................................. 75
■Replacing the HMI connecting cable .................................................. 76
■Checking the plate heat exchanger .................................................... 76
■Removing the hydraulic unit ............................................................... 77
Index
Index
6173886

7
■Checking the fuse ............................................................................... 79
8. Function description Appliance functions ................................................................................ 80
■Heating mode ..................................................................................... 80
■OpenTherm controller ......................................................................... 80
■Venting program ................................................................................. 80
■Filling program .................................................................................... 80
■Heating curve ..................................................................................... 80
DHW heating ......................................................................................... 82
External heating circuit hook-up (if installed) ......................................... 82
9. Connection and wiring dia-
gram
HBMU heat management unit ............................................................... 83
10. Commissioning/service
reports
................................................................................................................ 86
11. Specification Gas condensing combi boiler ................................................................ 88
Flue system types .................................................................................. 90
Gas categories ....................................................................................... 90
Electronic combustion control unit ......................................................... 91
12. Disposal Final decommissioning and disposal ..................................................... 92
13. Certificates Declaration of conformity ....................................................................... 93
14. Keyword index ................................................................................................................ 94
Index
Index (cont.)
6173886

8
Please dispose of packaging waste in line with statu-
tory regulations.
Gas Council No.
Type Gas Council Number:
Vitodens 050-W, B0KA, 25 kW 47-819-55
Vitodens 050-W, B0KA, 30 kW 47-819-57
Vitodens 050-W, B0KA-M, 25 kW 47-819-56
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
Disposal of packaging
6173886
Information

9
The appliance is intended solely for installation and
operation in sealed unvented heating systems that
comply with EN 12828 (as well as CECS215-2017 and
CE: CS215-2017 in relation to CN), with due attention
paid to the associated installation, service and operat-
ing instructions. It is only designed for heating up heat-
ing water that is of potable water quality.
Intended use presupposes that a fixed installation in
conjunction with permissible, system-specific compo-
nents has been carried out.
Commercial or industrial usage for a purpose other
than heating the building or DHW shall be deemed
inappropriate.
Any usage beyond this must be approved by the man-
ufacturer in each individual case.
Incorrect usage or operation of the appliance (e.g. the
appliance being opened by the system user) is prohibi-
ted and will result in an exclusion of liability. Incorrect
usage also occurs if the components in the heating
system are modified from their intended use (e.g. if the
flue gas and ventilation air paths are sealed).
Product information
Wall mounted gas condensing boiler with Inox-Radial
heat exchanger and the following integrated compo-
nents:
■Modulating MatriX-Plus burner for natural gas
■Hydraulics with 3-way diverter valve and variable
speed high efficiency circulation pump
■Type BPKA, B0KA: Plate heat exchanger for DHW
heating
■Weather-compensated or constant temperature con-
trol unit
■Integral diaphragm expansion vessel (8 l capacity)
The selected gas category in the delivered condition
and the associated nominal gas pressure are given on
the boiler type plate. The type plate also shows the
other gas types and pressures with which the boiler
can be operated. A conversion within the stated natu-
ral gas groups is not required.
Type plate
A
Fig. 1
AType plate with access code for appliance registra-
tion
The type plate of the heat generator contains exten-
sive product information and an appliance-specific
access code with the marking "i" for direct access to
product-specific information and product registration
on the internet.
The access code contains the credentials for the regis-
tration and product information portal, and the 16-digit
serial number.
Note
A further label with the access code is enclosed with
the heat generator.
Stick the label in the installation and service instruc-
tions so it can be easily found again for later use.
The Vitodens may generally only be delivered to the
countries listed on the type plate. For deliveries to
other countries, approved contractors must arrange
individual approval on their own initiative and in
accordance with the law of the country in question.
Information
Intended use
6173886
Information

10
System examples with hydraulic and electrical connec-
tion diagrams and function descriptions are available
to help setting up the heating system.
Detailed information on system examples can be found
at: 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
System examples
6173886
Information

11
350
126
308
700
767
58
58
123 123
109
A
B C D E
G F
1925
118
300
H
161
125
400
35
Ø 60.5
Ø 96 -0.5
+0.8
Fig. 2 Illustration shows a gas condensing combi
boiler
ACondensate drain
BHeating flow
CDHW (gas condensing combi boiler)
Cylinder flow (gas condensing system boiler)
DGas connection
ECold water (gas condensing combi boiler)
Cylinder return (gas condensing system boiler)
FHeating return
GFilling/draining
HDimension for siting with DHW cylinder below the
boiler
Preparing for installation
Preparing for installation
6173886
Installation

12
Note
This boiler (IP rating: IP X4) is approved for installation
in wet rooms inside safety zone 1, to DIN VDE 0100.
Exposure to jets of water must be prevented.
For open flue operation, the boiler may only be oper-
ated with a splash cover.
Observe the requirements of DIN VDE 0100.
1. Subject to order: Fit supplied pre-plumbing jig,
mounting frame or wall mounting bracket in the rel-
evant installation location.
Installation instructions for pre-plumbing jig
or mounting frame
Note
Check the condition of the wall where the boiler is
to be installed. For the suitability of the supplied
rawl plugs for various building materials, see man-
ufacturer's instructions: Fischer expansion plugs
SX 10 x 80
For other construction materials, use fixing materi-
als with sufficient load bearing capacity.
2. Prepare the water connections to the valves/fittings
of the mounting bracket.
Thoroughly flush the heating system.
!Please note
To prevent damage to the appliance,
connect all pipework so that it is free of load
and torque stress.
Note
If an on-site expansion vessel also has to be instal-
led: Install this expansion vessel in the cylinder
return, as the 3-way diverter valve is located in the
heating flow.
Not possible with type B0KA, BPKA
3. Prepare the gas connection according to TRGI or
TRF [or local regulations].
4. Prepare the electrical connections.
■The appliance is delivered fitted with a power
cable (approx. 2 m long).
Note
Connect the power cable to the electricity supply
using a fixed connection.
■Power supply: 230 V, 50 Hz, fuse rating
max. 16 A
■Accessory cables: 0.75 mm2 flexible PVC cable
with required number of cores for external con-
nections
Accessory cables: 1.5 mm2 flexible PVC cable
with required number of cores for external con-
nections
Connection on the DHW side for gas condensing combi boiler
Cold water installation
Fig. 3
ACold water connection of boiler
BDrain outlet
CVisible discharge pipe outlet point
DSafety valve
ENon-return valve
FShut-off valve
GCold water
HSafety assembly
Safety assembly H is included in the standard
delivery and requires installing.
Only use a non-return valve or a combined shut-off
and non-return valve in conjunction with a safety valve.
If the safety valve is used, the cold water shut-off valve
on the boiler must not be shut off.
Remove the toggle on the cold water shut-off valve (if
installed) to prevent manual shut-off.
Preparing for installation
Preparing for installation (cont.)
6173886
Installation

13
Shock arrestor
If draw-off points likely to cause water hammer are
connected to the boiler's DHW network (e.g. flush
valves, washing machines, dishwashers): Shock
arrestors should be installed close to the cause of the
water hammer.
Preparing for installation
Preparing for installation (cont.)
6173886
Installation

14
1.
4.
5.
3.
2.
Fig. 4
Installation sequence
Removing the boiler from the packaging
6173886
Installation

15
Removing the front panel
1.
2x
2.
3.
Fig. 5
1. Unlock the front panel on the underside (push in),
using a screwdriver or similar tool.
2. Swivel the front panel forwards slightly and lift
away upwards.
Mounting the boiler on the pre-plumbing jig or mounting frame
Note
Various installation components can be found in a sep-
arate pack. Keep the installation components safe, as
they will be required for later installation.
Installation sequence
Mounting the boiler and making connections
6173886
Installation

16
3.
2.
1.
37 37
4.
5.
4x
4x
Fig. 6
Note
The diagram shows installation on a pre-plumbing jig
for a gas condensing combi boiler.
The boiler can be installed on the following accesso-
ries:
■Pre-plumbing jig
■Mounting frame
■Plumbing wall mounting frame
1. Replace gaskets.
Internal gasket diameter:
■Gas connection Ø 18.5 mm
■Heating water side connections Ø 17.0 mm
Note
Gasket for gas connection is attached to the gas
shut-off valve.
2. Suspend the Vitodens from the wall mounting
bracket.
Note
After mounting, ensure correct seating.
Installation sequence
Mounting the boiler and making connections (cont.)
6173886
Installation

17
3. Note
Only remove the locking clip under the gas pipe
union nut once the appliance has been installed.
Clip is no longer required.
4. Tighten union nuts so that they form a tight seal.
Tighten the union nuts as tightly as necessary and
ensure that the components are undamaged and
are functioning correctly throughout service life.
Observe torque settings if a torque wrench is avail-
able.
Check for gas tightness to BSI 6891.
Torque settings:
■Union nuts G ¾: 30 Nm
■Union nuts G ½: 24 Nm
When carrying out any work on gas connection fit-
tings, hold with a suitable tool. Never transfer any
forces to the internal components.
5. Tighten locking ring fittings so that they form a tight
seal:
One turn beyond finger-tight.
Fitting the boiler to the wall mounting bracket
Note
Various installation components can be found in a sep-
arate pack. Keep the installation components safe, as
they will be required for later installation.
Installation sequence
Mounting the boiler and making connections (cont.)
6173886
Installation

18
1.
4.
3.
2.
37 37
Fig. 7
1. Replace gaskets. Fit valves and gas shut-off valve.
Internal gasket diameter:
■Gas connection Ø 18.5 mm
■Connections on the heating water side
Ø 17.0 mm
Note
Gasket for gas connection is attached to the gas
shut-off valve.
2. Suspend the Vitodens from the wall mounting
bracket.
3. Note
Only remove the locking clip under the gas pipe
union nut once the appliance has been installed.
Clip is no longer required.
Installation sequence
Mounting the boiler and making connections (cont.)
6173886
Installation

19
4. Tighten union nuts so that they form a tight seal.
Tighten the union nuts as tightly as necessary and
ensure that the components are undamaged and
are functioning correctly throughout service life.
Observe torque settings if a torque wrench is avail-
able.
Check for gas tightness to BSI 6891.
Torque settings:
■Union nuts G ¾: 30 Nm
■Union nuts G ½: 24 Nm
When carrying out any work on gas connection fit-
tings, hold with a suitable tool. Never transfer any
forces to the internal components.
Connections on the heating water and DHW sides
If the connections have not been fitted previously,
make the connections on the heating water and DHW
sides.
Gas condensing system boiler
B C D E FA
Fig. 8 Specifications for threads in conjunction with
connection accessories
AHeating flow R ¾ (male thread)
BCylinder flow G ¾ (male thread)
CGas connection R ¾ (male thread)
DCylinder return G ¾ (male thread)
EHeating return R ¾ (male thread)
FFilling/draining
Connection on the heating water side of the DHW
cylinder:
The required intermediate pieces (Rp ¾, female
thread) on the cylinder flow and return are part of the
connection set for the DHW cylinder.
If no DHW cylinder is being connected, seal off the
connections with caps.
Gas condensing combi boiler
FA B C D E
Fig. 9 Specifications for threads in conjunction with
connection accessories
AHeating flow R ¾ (male thread)
BDHW R ½ (male thread)
CGas connection R ¾ (male thread)
DCold water R ½ (male thread)
EHeating return R ¾ (male thread)
FFilling/draining
Scald protection
DHW temperatures of over 60 °C can occur with gas
condensing combi boilers. As a result, scald protection
should be installed on site in the DHW pipe.
Installation sequence
Mounting the boiler and making connections (cont.)
6173886
Installation

20
Fig. 10
1. Push the supplied drain hose on to the drain con-
nector.
2. Connect the drain hose with a constant fall and a
pipe vent to the drain network or a neutralising sys-
tem.
Note
Route the onward drain line inside the building as
far as possible.
If the onward drain line is routed outside the build-
ing:
■Use a min. Ø 30 mm line.
■Protect the line from frost.
■Keep the line as short as possible.
!Please note
The drain hose is used to route away any
hot water discharged from the safety valve.
Lay and secure the drain hose in a way that
prevents any risk of scalding.
Note
Observe local waste water regulations.
Filling the trap with water
Fig. 11
Pour at least 0.3 l of water into the flue gas connection.
!Please note
During commissioning, flue gas may escape
from the condensate drain.
Always fill the trap with water before commis-
sioning.
Note
If there is a risk of frost, only fill the trap just before
commissioning.
Installation sequence
Condensate connection
6173886
Installation