Vaillant aroTHERM plus VWL 35/6 A 230V S2 User manual

en Operating instructions
en Installation and maintenance instructions
aroTHERM plus
VWL 105/6 A 230V S2 ... VWL 125/6 A S2
0020330792_00 - 11.04.2022

2
en Operating instructions ....................................... 3
en Installation and maintenance instructions...... 11

0020330792_00 Operating instructions 3
Operating instructions
Contents
1 Safety .................................................................... 4
1.1 Action-related warnings ......................................... 4
1.2 Intended use .......................................................... 4
1.3 General safety information .................................... 4
2 Notes on the documentation .............................. 6
2.1 Documents............................................................. 6
2.2 Validity of the instructions...................................... 6
3 Product description............................................. 6
3.1 Heat pump system................................................. 6
3.2 Description of the product...................................... 6
3.3 Functions of the heat pump ................................... 6
3.4 System separation and frost protection ................. 6
3.5 Product design....................................................... 6
3.6 Data plate and serial number ................................ 6
3.7 Warning sticker ...................................................... 7
4 Protective zone .................................................... 7
4.1 Protective zone ...................................................... 7
4.2 Design of the condensate discharge ..................... 8
5 Operation.............................................................. 9
5.1 Switching on the product ....................................... 9
5.2 Operating the product............................................ 9
5.3 Guaranteeing frost protection ................................ 9
5.4 Switching off the product ....................................... 9
6 Care and maintenance ........................................ 9
6.1 Keeping the product clear...................................... 9
6.2 Cleaning the product.............................................. 9
6.3 Carrying out maintenance work............................. 9
7 Troubleshooting .................................................. 9
7.1 Eliminating faults.................................................... 9
8 Decommissioning................................................ 9
8.1 Temporarily decommissioning the product............ 9
8.2 Permanently decommissioning the product........... 9
9 Recycling and disposal....................................... 9
9.1 Arranging disposal of refrigerant ......................... 10
10 Guarantee and customer service..................... 10
10.1 Guarantee............................................................ 10
10.2 Customer service................................................. 10

4Operating instructions 0020330792_00
1 Safety
1.1 Action-related warnings
Classification of action-related warnings
The action-related warnings are classified in
accordance with the severity of the possible
danger using the following warning symbols
and signal words:
Warning symbols and signal words
Danger!
Imminent danger to life or risk of
severe personal injury
Danger!
Risk of death from electric shock
Warning.
Risk of minor personal injury
Caution.
Risk of material or environmental
damage
1.2 Intended use
There is a risk of injury or death to the user or
others, or of damage to the product and other
property in the event of improper use or use
for which it is not intended.
The product is the outdoor unit of an air-to-
water heat pump with monoblock design.
The product uses the outdoor air as a heat
source and can be used to heat a residential
building and for domestic hot water genera-
tion.
The air that escapes from the product must
be able to flow out freely, and must not be
used for any other purposes.
The product is only intended for outdoor in-
stallation.
The product is intended exclusively for do-
mestic use.
Intended use includes the following:
–observance of the operating instructions
included for the product and any other
installation components
–compliance with all inspection and main-
tenance conditions listed in the instruc-
tions.
This product can be used by children aged
from 8 years and above and persons with
reduced physical, sensory or mental capabil-
ities or lack of experience and knowledge if
they have been given supervision or instruc-
tion concerning use of the product in a safe
way and understand the hazards involved.
Children must not play with the product.
Cleaning and user maintenance work must
not be carried out by children unless they are
supervised.
Any other use that is not specified in these
instructions, or use beyond that specified in
this document, shall be considered improper
use. Any direct commercial or industrial use
is also deemed to be improper.
Caution.
Improper use of any kind is prohibited.
1.3 General safety information
1.3.1 Risk of death caused by fire or
explosion if there is a leak in the
refrigerant circuit
The product contains the combustible refri-
gerant R290. In the event of a leak, escaping
refrigerant may mix with air to form a flam-
mable atmosphere. There is a risk of fire and
explosion.
A protective zone is defined for the area
close around the product. See section
"Protective zone".
▶Ensure that there are no ignition sources,
such as plug sockets, light switches,
lamps, electrical switches or other per-
manent ignitions sources, in the protective
zone.
▶Do not use any sprays or other combust-
ible gases in the protective zone.
1.3.2 Risk of death due to changes to the
product or the product environment
▶Never remove, bridge or block the safety
devices.
▶Do not tamper with any of the safety
devices.
▶Do not damage or remove any tamper-
proof seals on components.
▶Do not make any changes:
–The product itself
–To the supply lines
–On the drain pipework
–On the expansion relief valve for the
heat source circuit

0020330792_00 Operating instructions 5
–to constructional conditions that may
affect the operational reliability of the
product
1.3.3 Risk of injury and material damage
due to maintenance and repairs
carried out incorrectly or not carried
out at all
▶Never attempt to carry out maintenance
work or repairs on your product yourself.
▶Faults and damage should be immediately
eliminated by a competent person.
▶Adhere to the maintenance intervals spe-
cified.
1.3.4 Risk of material damage caused by
frost
▶Ensure that the heating installation always
remains in operation during freezing con-
ditions and that all rooms are sufficiently
heated.
▶If you cannot ensure the operation, have a
competent person drain the heating install-
ation.
1.3.5 Danger caused by improper
operation
Improper operation may present a danger to
you and others, and cause material damage.
▶Carefully read the enclosed instructions
and all other applicable documents, par-
ticularly the "Safety" section and the warn-
ings.
▶Only carry out the activities for which in-
structions are provided in these operating
instructions.

6Operating instructions 0020330792_00
2 Notes on the documentation
2.1 Documents
▶Always observe all operating instructions enclosed with
the installation components.
▶Store these instructions and all other applicable docu-
ments for further use.
2.2 Validity of the instructions
These instructions apply only to:
Product
VWL 105/6 A 230V S2
VWL 105/6 A S2
VWL 125/6 A 230V S2
VWL 125/6 A S2
3 Product description
3.1 Heat pump system
Design of a typical heat pump system with monoblock tech-
nology:
1 2
4
3
5
6
1 Outdoor unit
2 eBUS line
3 System control
4 Control for the indoor
unit
5 Indoor unit with do-
mestic hot water cylin-
der
6 Heating circuit
3.2 Description of the product
The product is the outdoor unit of an air-to-water heat pump
with monoblock technology.
3.3 Functions of the heat pump
The heat pump has a closed refrigerant circuit in which refri-
gerant circulates.
Cyclic evaporation, compression, liquefaction and expansion
takes in heat energy from the surroundings and transfers it to
the building. In cooling mode, heat energy is extracted from
the building and released into the environment.
3.4 System separation and frost protection
With a system separation, an intermediate heat exchanger is
installed in the indoor unit. This separates the heating circuit
into a primary heating circuit (to the outdoor unit) and a sec-
ondary heating circuit (in the building).
If the primary heating circuit is filled with a water/frost protec-
tion mixture (brine fluid), the outdoor unit is then protected
against freezing, even if this is electrically switched off or in
the case of a power cut.
3.5 Product design
3
1
2
1 Air inlet grille
2 Data plate
3 Air outlet grille
3.6 Data plate and serial number
The data plate is located on the right-hand side of the pro-
duct's exterior.
The data plate includes the nomenclature and the serial
number.

0020330792_00 Operating instructions 7
3.7 Warning sticker
Safety-relevant stickers are affixed to several points on the
product. The warning stickers include rules of conduct for the
R290 refrigerant. The warning stickers must not be removed.
Symbol Meaning
R290
Warning against flammable materials in
conjunction with R290 refrigerant.
Fire, naked flames and smoke are prohib-
ited.
Read the service information and technical
instructions.
4 Protective zone
4.1 Protective zone
The product contains R290 refrigerant. Note that this refri-
gerant has a higher density than air. In the event of a leak,
escaping refrigerant may collect near the ground.
The refrigerant must not collect in any way that may lead
to a dangerous, explosive, suffocating or toxic atmosphere.
The refrigerant must not get inside the building via building
openings. The refrigerant must not collect in grooves.
A protective zone is defined around the product. There must
be no windows, doors, light shafts, cellar entrances, escape
hatches, flat-roof windows or ventilation openings in the pro-
tective zone.
There must be no ignition sources, such as plug sockets,
light switches, lamps, electrical switches or other permanent
ignitions sources, in the protective zone.
The protective zone must not extend to adjacent buildings or
public traffic areas.
In the protective zone, you are not permitted to make any
subsequent structural alterations which infringe the stated
rules for the protective zone.
4.1.1 Protective zone for ground installation on
the premises
A
A 1000 mm
4.1.2 Protective zone for ground installation in
front of a building wall
C
D
A
B
A 2100 mm
B 3100 mm
C 200 mm/250 mm
D 1000 mm
4.1.3 Protective zone for ground installation in a
building corner
A
B
C
D
E
F
G
A 2100 mm
B 2600 mm
C 200 mm/250 mm
D 500 mm
E 1000 mm
F 500 mm
G 1800 mm

8Operating instructions 0020330792_00
4.1.4 Protective zone for wall installation in front
of a building wall
C
D
A
B
A 2100 mm
B 3100 mm
C 200 mm/250 mm
D 1000 mm
The protective zone below the product extends as far as the
floor.
4.1.5 Protective zone for wall installation in a
building corner
B
C
D
E
F
G
A
A 2100 mm
B 2600 mm
C 200 mm/250 mm
D 500 mm
E 1000 mm
F 500 mm
G 1800 mm
The protective zone below the product extends as far as the
floor.
4.1.6 Protective zone for flat-roof installation
A
A 1000 mm
4.2 Design of the condensate discharge
The condensate that accumulates can be guided into a
sewer, pump sump or soakaway via a downpipe, gully,
balcony run-off or roof run-off. Open gullies or downpipes
within the protective zone do not pose any safety risk.
For all installation types, you must ensure that any condens-
ate that accumulates is discharged frost-free.
4.2.1 Design of the condensate discharge for
ground installation
For the ground installation, the condensate must be dis-
charged via a downpipe into a gravel bed which is located
in the frost-free area.
100
100
A
For a region with ground frost, dimension A is ≥900 mm
and, for a region without ground frost, it is ≥600 mm.
The downpipe must flow into a sufficiently large gravel bed
so that the condensate can trickle away freely.
To prevent the condensate from freezing, the heating wire
must be threaded into the downpipe via the condensate dis-
charge tundish.
4.2.2 Design of the condensate discharge for wall
installation
For wall installation, the condensate can be discharged into
a gravel bed that is located below the product.
Alternatively, the condensate can be discharged by con-
necting the condensate discharge pipe to a downpipe. In
this case, depending on the local conditions, you must use

0020330792_00 Operating instructions 9
electrical trace heating in order to keep the condensate dis-
charge pipe frost-free.
4.2.3 Design of the condensate discharge for flat-
roof installation
For flat-roof installation, the condensate can be discharged
by connecting a condensate discharge pipe to a downpipe or
a roof run-off. In this case, depending on the local conditions,
you must use electrical trace heating in order to keep the
condensate discharge pipe frost-free.
5 Operation
5.1 Switching on the product
▶Switch on all of the disconnectors to which the product is
connected in the building.
5.2 Operating the product
It is operated via the indoor unit's control (→Operating in-
structions for the indoor unit).
5.3 Guaranteeing frost protection
1. If no system separation for guaranteeing the frost pro-
tection is present, ensure that the product is switched
on and remains switched on.
2. Ensure that no snow accumulates around the air inlet
grille and air outlet grille.
5.4 Switching off the product
1. Switch off all of the disconnectors to which the product
is connected in the building.
2. Note that this means that frost protection is no longer
guaranteed if no system separation for guaranteeing
the frost protection is present.
6 Care and maintenance
6.1 Keeping the product clear
1. Regularly remove branches and leaves that have
gathered around the product.
2. Regularly remove leaves and dirt from the ventilation
grille below the product.
3. Regularly remove snow from the air inlet grille and from
the air outlet grille.
4. Regularly remove snow that has gathered around the
product.
6.2 Cleaning the product
1. Clean the casing with a damp cloth and a little solvent-
free soap.
2. Do not use sprays, scouring agents, detergents,
solvents or cleaning agents that contain chlorine.
6.3 Carrying out maintenance work
Danger!
Risk of injury and risk of material damage
due to neglected or incorrect maintenance
and repairs.
Neglected or incorrect maintenance work or
repairs may lead to personal injury or dam-
age to the product.
▶Never attempt to carry out maintenance
work or repairs on the product.
▶Employ an authorised installation com-
pany to complete such work. We recom-
mend making a maintenance contract.
7 Troubleshooting
7.1 Eliminating faults
▶If you observe a cloud of vapour on the product, you do
not have to do anything. This effect may arise during the
thawing process.
▶If the product will no longer start up, check whether the
power supply is interrupted. If required, switch on all of
the disconnectors to which the product is connected in
the building.
▶Contact a competent person if the measure that is de-
scribed is unsuccessful.
8 Decommissioning
8.1 Temporarily decommissioning the product
1. Switch off all of the disconnectors to which the product
is connected in the building.
2. Protect the heating installation against frost.
8.2 Permanently decommissioning the product
▶Have a competent person permanently decommission
the product.
9 Recycling and disposal
▶The competent person who installed your product is re-
sponsible for the disposal of the packaging.
Disposing of the product
If the product is labelled with this mark:
▶In this case, do not dispose of the product with the
household waste.
▶Instead, hand in the product to a collection centre for
waste electrical or electronic equipment.
Disposing of batteries
If the product contains batteries that are labelled with
this mark:

10 Operating instructions 0020330792_00
▶In this case, dispose of the batteries at a collection point
for batteries.
◁Prerequisite: The batteries can be removed from
the product without causing any destruction. Other-
wise, the batteries are disposed of together with the
product.
▶In accordance with the legal regulations, used batteries
must be returned since batteries may contain substances
that are harmful to health and the environment.
9.1 Arranging disposal of refrigerant
The product is filled with R290 refrigerant.
▶Refrigerant must only be disposed of by an authorised
competent person.
▶Observe the general safety information.
10 Guarantee and customer service
10.1 Guarantee
Vaillant provides a full parts and labour guarantee for this
appliance for the duration as shown on the enclosed re-
gistration card which must be fully completed and returned
within 30 days of installation. All appliances must be installed
by a suitably competent person fully conversant and in ac-
cordance with all current regulations applicable to the ap-
pliance type installation. In the case of gas appliances the
Gas Safety (Installation and Use) Regulations 1998, and the
manufacturer’s instructions. In the UK competent persons
approved at the time by the Health and Safety Executive un-
dertake the work in compliance with safe and satisfactory
standards. Installers should also be fully conversant with and
competent with all necessary electrical and building regula-
tions that may apply to the installation.
In addition all unvented domestic hot water cylinders must
be installed by a competent person to the prevailing build-
ing regulations at the time of installation (G3). All appliances
shall be fully commissioned in accordance with our installa-
tion manual and Benchmark commissioning check list (this
will be included within the installation manual). These must
be signed and given to the user for safe keeping during the
hand over process. Installers should also at this time advise
the user of the annual servicing requirements and advise of
appropriate service agreement.
Terms and conditions do apply to the guarantee, details of
which can be found on the registration card included with this
appliance. In order to qualify for guarantee after one year the
appliance must be serviced in accordance with our installa-
tion manual servicing instructions. The benchmark service
history should be completed. Note - all costs associated with
this service are excluded from this guarantee.
Failure to install and commission this appliance in compli-
ance with the manufacturer’s instructions will invalidate the
guarantee (this does not affect the customer’s statutory
rights).
10.2 Customer service
For contact details for our customer service department, you
can write to the address that is provided on the back page,
or you can visit www.vaillant.co.uk.

0020330792_00 Installation and maintenance instructions 11
Installation and maintenance
instructions
Contents
1 Safety .................................................................. 13
1.1 Action-related warnings ....................................... 13
1.2 Intended use ........................................................ 13
1.3 General safety information .................................. 13
1.4 Regulations (directives, laws, standards) ............ 14
2 Notes on the documentation ............................ 15
2.1 Documents........................................................... 15
2.2 Validity of the instructions.................................... 15
2.3 Further information .............................................. 15
3 Product description........................................... 15
3.1 Heat pump system............................................... 15
3.2 Description of the product.................................... 15
3.3 Cooling mode....................................................... 15
3.4 Functions of the heat pump ................................. 15
3.5 Product design..................................................... 16
3.6 Information on the data plate............................... 17
3.7 Warning sticker .................................................... 18
3.8 CE marking .......................................................... 18
3.9 Benchmark........................................................... 18
3.10 Application limits .................................................. 18
3.11 Thawing mode ..................................................... 19
3.12 Safety devices ..................................................... 19
4 Protective zone .................................................. 19
4.1 Protective zone .................................................... 19
4.2 Design of the condensate discharge ................... 21
5 Set-up.................................................................. 22
5.1 Checking the scope of delivery............................ 22
5.2 Transporting the product ..................................... 22
5.3 Dimensions .......................................................... 22
5.4 Complying with minimum clearances .................. 23
5.5 Conditions for the installation type....................... 24
5.6 Selecting the installation site ............................... 24
5.7 Preparing for fitting and installation ..................... 25
5.8 Creating a foundation .......................................... 25
5.9 Guaranteeing occupational safety ....................... 25
5.10 Installing the product............................................ 25
5.11 Connecting the condensate discharge pipe ........ 26
5.12 Setting up a protective wall.................................. 27
5.13 Removing/installing the casing sections.............. 27
6 Hydraulics installation ...................................... 28
6.1 Installation type: Direct connection or system
separation ............................................................ 28
6.2 Guaranteeing the minimum circulation water
volume ................................................................. 28
6.3 Requirements for hydraulic components ............. 28
6.4 Preparing the hydraulics installation.................... 28
6.5 Routing pipelines to the product .......................... 28
6.6 Connecting the pipelines to the product .............. 29
6.7 Completing the hydraulics installation ................. 29
6.8 Option: Connecting the product to a swimming
pool ...................................................................... 29
7 Electrical installation......................................... 29
7.1 Preparing the electrical installation...................... 29
7.2 Requirements for the quality of the mains
voltage ................................................................. 30
7.3 Requirements for electrical components ............. 30
7.4 Electrical partition ................................................ 30
7.5 Installing components for the energy supply
company lockout function .................................... 30
7.6 Removing the cover for the electrical
connections.......................................................... 30
7.7 Stripping the electrical wire.................................. 30
7.8 Establishing the power supply, 1~/230V.............. 30
7.9 Establishing the power supply, 3~/400V.............. 31
7.10 Connecting the eBUS line ................................... 32
7.11 Connecting a limit thermostat .............................. 32
7.12 Connecting accessories ...................................... 32
7.13 Installing the cover for the electrical
connections.......................................................... 32
8 Start-up ............................................................... 32
8.1 Checking before switching on.............................. 32
8.2 Switching on the product ..................................... 32
8.3 Checking and treating the heating water/filling
and supplementary water .................................... 32
8.4 Filling and purging the heating circuit .................. 33
8.5 Available remaining feed pressure ...................... 33
9 Handing over to the end user........................... 34
9.1 Instructing the end user ....................................... 34
10 Troubleshooting ................................................ 34
10.1 Fault messages ................................................... 34
10.2 Other faults .......................................................... 34
11 Inspection and maintenance ............................ 34
11.1 Preparing for inspection and maintenance .......... 34
11.2 Observing the work plan and intervals ................ 34
11.3 Procuring spare parts .......................................... 34
11.4 Carrying out maintenance work........................... 35
11.5 Completing inspection and maintenance............. 36
12 Repair and service............................................. 36
12.1 Preparing repair and service work on the
refrigerant circuit .................................................. 36
12.2 Removing refrigerant from the product................ 36
12.3 Removing components of the refrigerant
circuit ................................................................... 37
12.4 Installing components of the refrigerant circuit .... 37
12.5 Filling the product with refrigerant ....................... 37
12.6 Completing repair and service work .................... 37
13 Decommissioning.............................................. 38
13.1 Temporarily decommissioning the product.......... 38
13.2 Permanently decommissioning the product......... 38
14 Recycling and disposal..................................... 38
14.1 Disposing of the packaging ................................. 38
14.2 Disposing of the refrigerant ................................. 38

12 Installation and maintenance instructions 0020330792_00
15 Customer service............................................... 38
15.1 Customer service................................................. 38
Appendix ............................................................................ 39
A Functional diagram............................................ 39
B Safety devices.................................................... 40
C Wiring diagram................................................... 41
C.1 Wiring diagram, power supply, 1~/230V.............. 41
C.2 Wiring diagram, power supply, 3~/400V.............. 42
C.3 Wiring diagram, sensors and actuators ............... 43
D Inspection and maintenance work................... 44
E Technical data.................................................... 44
F Commissioning Checklist................................. 47
Index ................................................................................... 50

0020330792_00 Installation and maintenance instructions 13
1 Safety
1.1 Action-related warnings
Classification of action-related warnings
The action-related warnings are classified in
accordance with the severity of the possible
danger using the following warning symbols
and signal words:
Warning symbols and signal words
Danger!
Imminent danger to life or risk of
severe personal injury
Danger!
Risk of death from electric shock
Warning.
Risk of minor personal injury
Caution.
Risk of material or environmental
damage
1.2 Intended use
There is a risk of injury or death to the user or
others, or of damage to the product and other
property in the event of improper use or use
for which it is not intended.
The product is the outdoor unit of an air-to-
water heat pump with monoblock design.
The product uses the outdoor air as a heat
source and can be used to heat a residential
building and for domestic hot water genera-
tion.
The air that escapes from the product must
be able to flow out freely, and must not be
used for any other purposes.
The product is only intended for outdoor in-
stallation.
The product is intended exclusively for do-
mestic use.
Intended use includes the following:
–observance of accompanying operating,
installation and maintenance instructions
for the product and any other system com-
ponents
–installing and setting up the product in ac-
cordance with the product and system ap-
proval
–compliance with all inspection and main-
tenance conditions listed in the instruc-
tions.
Intended use also covers installation in ac-
cordance with the IP code.
Any other use that is not specified in these
instructions, or use beyond that specified in
this document, shall be considered improper
use. Any direct commercial or industrial use
is also deemed to be improper.
Caution.
Improper use of any kind is prohibited.
1.3 General safety information
1.3.1 Risk caused by inadequate
qualifications
The following work must only be carried out
by competent persons who are sufficiently
qualified to do so:
–Set-up
–Dismantling
–Installation
–Start-up
–Inspection and maintenance
–Repair
–Decommissioning
▶Proceed in accordance with current tech-
nology.
1.3.2 Risk caused by inadequate
qualifications for the R290 refrigerant
Any activity that requires the unit to be
opened must only be carried out by com-
petent persons who have knowledge about
the particular properties and risks of R290
refrigerant.
Specific expert refrigeration knowledge in
compliance with the local laws is required
when carrying out work on the refrigerant cir-
cuit. This also includes specialist knowledge
about handling flammable refrigerants, the
corresponding tools and the required per-
sonal protective equipment.
▶Comply with the corresponding local laws
and regulations.
1.3.3 Risk of death from electric shock
There is a risk of death from electric shock if
you touch live components.

14 Installation and maintenance instructions 0020330792_00
Before commencing work on the product:
▶Disconnect the product from the power
supply by switching off all power supplies
at all poles (electrical partition in over-
voltage category III for full partition, e.g.
fuse or circuit breaker).
▶Secure against being switched back on
again.
▶Wait for at least 3 minutes until the capa-
citors have discharged.
▶Check that there is no voltage.
1.3.4 Risk of death caused by fire or
explosion if there is a leak in the
refrigerant circuit
The product contains the combustible refri-
gerant R290. In the event of a leak, escaping
refrigerant may mix with air to form a flam-
mable atmosphere. There is a risk of fire and
explosion.
A protective zone is defined for the area
close around the product. See section
"Protective zone".
▶If you are working on the product when it
is open, before starting work, use a gas
sniffer to ensure that there is no leak.
▶The gas sniffer itself must not be an igni-
tion source. The gas sniffer must be calib-
rated to R290 refrigerant and set to ≤25%
of the lower explosive limit.
▶Keep all ignition sources away from the
protective zone. In particular, open flames,
hot surfaces with temperatures above
370 °C, electrical devices or tools that are
not free from electrical sources, static dis-
charges.
1.3.5 Risk of death caused by fire
or explosion when removing the
refrigerant
The product contains the combustible refri-
gerant R290. The refrigerant may mix with air
to form a flammable atmosphere. There is a
risk of fire and explosion.
▶Only carry out the work if you are compet-
ent at handling R290 refrigerant.
▶Wear suitable personal protective equip-
ment and bring a fire extinguisher with you.
▶Only use tools and units that are permit-
ted for R290 refrigerant and are in proper
working condition.
▶Ensure that no air gets into the refrigerant
circuit, into refrigerant-carrying tools or
units, or into the refrigerant cylinder.
▶Note that the refrigerant R290 must never
be introduced into the sewage system.
1.3.6 Risk of death due to lack of safety
devices
The basic diagrams included in this docu-
ment do not show all safety devices required
for correct installation.
▶Install the necessary safety devices in the
installation.
▶Observe the applicable national and inter-
national laws, standards and directives.
1.3.7 Risk of burns, scalds and frostbite
due to hot and cold components
There is a risk of burns and frostbite from
some components, particularly uninsulated
pipelines.
▶Only carry out work on the components
once these have reached environmental
temperature.
1.4 Regulations (directives, laws,
standards)
▶Observe the national regulations, stand-
ards, directives, ordinances and laws.

0020330792_00 Installation and maintenance instructions 15
2 Notes on the documentation
2.1 Documents
▶Always observe all the operating and installation instruc-
tions included with the system components.
▶Pass these instructions and all other applicable docu-
ments on to the end user.
2.2 Validity of the instructions
These instructions apply only to:
Product
VWL 105/6 A 230V S2
VWL 105/6 A S2
VWL 125/6 A 230V S2
VWL 125/6 A S2
2.3 Further information
▶Scan the displayed code using your smartphone in order
to view further information about the installation.
◁You are guided to installation videos.
3 Product description
3.1 Heat pump system
Design of a typical heat pump system with monoblock tech-
nology:
1 2
4
3
5
6
1 Outdoor unit
2 eBUS line
3 System control
4 Control for the indoor
unit
5 Indoor unit with do-
mestic hot water cylin-
der
6 Heating circuit
3.2 Description of the product
The product is the outdoor unit of an air-to-water heat pump
with monoblock technology.
3.3 Cooling mode
Depending on the country, the product has the heating mode
or heating and cooling mode function.
Products that are delivered at the factory with no cooling
mode are labelled with "S2" in the nomenclature. For these
units, an optional accessory can be used to subsequently
activate the cooling mode.
3.4 Functions of the heat pump
The heat pump has a closed refrigerant circuit in which refri-
gerant circulates.
In heating mode, cyclic evaporation, compression, liquefac-
tion and expansion take in heat energy from the surround-
ings and transfer it to the building. In cooling mode, heat
energy is extracted from the building and released into the
environment.
3.4.1 Operating principle in heating mode
65
43
1
2
1 Evaporator
2 4-port diverter valve
3 Fan
4 Compressor
5 Expansion valve
6 Condenser
3.4.2 Operating principle in cooling mode
Validity: Product with cooling mode
65
43
1
2
1 Condenser
2 4-port diverter valve
3 Fan
4 Compressor
5 Expansion valve
6 Evaporator

16 Installation and maintenance instructions 0020330792_00
3.4.3 Noise reduction mode
A noise reduction mode can be activated for the product.
In noise reduction mode, the product operates more quietly
than in normal operating mode. This is achieved using a
limited compressor rotational speed and an adjusted fan
speed.
3.5 Product design
3.5.1 Unit
1
1 Air outlet grille
1
2
3
4
6
5
1 Evaporator 2 INSTALLER BOARD
PCB
3 HMU PCB
4 Compressor assembly
5 INVERTER assembly
6 Fan
3
4
1
2
5
1 Temperature sensor at
the air inlet
2 Air inlet grille
3 Connection for heating
flow
4 Connection for heating
return
5 Cover for the electrical
connections

0020330792_00 Installation and maintenance instructions 17
3.5.2 Compressor assembly
1
2
3
6
4
5
7
8
9
12
14
13
15
11
10
1 Automatic air vent
2 Separator
3 Expansion relief valve
4 Filter
5 Condenser
6 Pressure sensor in the
heating circuit
7 Heating pump
8 Flow rate sensor
9 Maintenance connection
in the low-pressure area
10 Pressure switch in the
high-pressure area
11 Pressure sensor in the
high-pressure area
12 Maintenance connection
in the high-pressure
area
13 Compressor
14 Electronic expansion
valve
15 4-port diverter valve
1
2
3
4
5
1 Pressure sensor in the
low-pressure area
2 Filter
3 Refrigerant buffer
4 Connection for heating
flow
5 Connection for heating
return
3.6 Information on the data plate
The data plate is located on the right-hand side of the pro-
duct's exterior.
A second data plate is located inside the product. It becomes
visible when the top casing is removed.
Information Meaning
Serial no. Unique unit identification number
VWL ... Nomenclature
IP Protection class
Compressor
Control
P max Rated power, maximum
I max Rated current, maximum
I In-rush current

18 Installation and maintenance instructions 0020330792_00
Information Meaning
MPa (bar) Permissible operating pressure
Refrigerant circuit
R290 Refrigerant type
GWP Global Warming Potential
kg Fill quantity
t CO2CO2equivalent
Ax/Wxx Air inlet temperature x °C and heating flow
temperature xx °C
COP / Coefficient of performance/heating mode
EER / Energy efficiency ratio/cooling mode
3.7 Warning sticker
Safety-relevant stickers are affixed to several points on the
product. The warning stickers include rules of conduct for the
R290 refrigerant. The warning stickers must not be removed.
Symbol Meaning
R290
Warning against flammable materials in
conjunction with R290 refrigerant.
Fire, naked flames and smoke are prohib-
ited.
Read the service information and technical
instructions.
3.8 CE marking
The CE marking shows that the products comply with the
basic requirements of the applicable directives as stated on
the declaration of conformity.
The declaration of conformity can be viewed at the manufac-
turer's site.
3.9 Benchmark
Vaillant is a licensed member of the Benchmark Scheme.
Benchmark places responsibilities on both manufacturers
and installers. The purpose is to ensure that customers are
provided with the correct equipment for their needs, that it is
installed, commissioned and serviced in accordance with the
manufacturer’s instructions by a competent person approved
at the time by the Health and Safety Executive and that it
meets the requirements of the appropriate Building Regu-
lations. The Benchmark Checklist can be used to demon-
strate compliance with Building Regulations and should be
provided to the customer for future reference.
Installers are required to carry out installation, commission-
ing and servicing work in accordance with the Benchmark
Code of Practice which is available from the Heating and
Hotwater Industry Council who manage and promote the
Scheme.
Benchmark is managed and promoted by the Heating and
Hotwater Industry Council.
For more information visit www.centralheating.co.uk
3.10 Application limits
The product works between a minimum and maximum out-
door temperature. These outdoor temperatures define the
application limits for the heating mode, domestic hot water
generation and cooling mode. Operating outside of the ap-
plication limits leads to the product switching off.
3.10.1 Application limits, heating mode
In heating mode, the product works at outdoor temperatures
of -25 °C to 43 °C.
010-10-20-30
0
10
20
30
40
50
60
70
80
20 30 40 50
A
B
1
2
A Outdoor temperature
B Heating water temperat-
ure
1 Application limits, heat-
ing mode
2 Area of application, in
accordance with EN
14511
3.10.2 Application limits, domestic hot water
generation
For domestic hot water generation, the product works at out-
door temperatures of -20 °C to 43 °C.

0020330792_00 Installation and maintenance instructions 19
010-10-20
0
10
20
30
40
50
60
70
80
20 30 40 50
A
B
A Outdoor temperature B Heating water temperat-
ure
3.10.3 Application limits, cooling mode
Validity: Product with cooling mode
In cooling mode, the product works at outdoor temperat-
ures of 15 °C to 46 °C.
25 30201510
0
5
10
15
20
25
30
35
35 40 45 50
A
B
A Outdoor temperature B Heating water temper-
ature
3.11 Thawing mode
At outdoor temperatures below 5 °C, condensation on the
fins of the evaporator may freeze and frost may form. This
frost is automatically detected and is automatically thawed at
certain intervals.
The thawing occurs by reversing the refrigeration circuit
while the heat pump is operating. The heat energy that is
required for this is taken from the heating installation.
Correct thawing operation is only possible if the minimum
volume of heating water is circulating in the heating installa-
tion:
Activated back-
up heater, heating
water temperature
> 25 °C
Deactivated back-
up heater, heating
water temperature
> 15 °C
45 litres 150 litres
3.12 Safety devices
The product is equipped with technical safety devices. See
"Safety devices" graphic in the appendix.
If the refrigerant circuit pressure exceeds the maximum pres-
sure of 3.15 MPa (31.5 bar), the pressure switch temporarily
switches the product off. Following a waiting period, another
attempt is made to start it. After three failed start attempts in
succession, a fault message is displayed.
If the product is switched off, the crankcase housing heat-
ing is switched on when the compressor outlet temperat-
ure reaches 7 °C. This prevents possible damage caused
by switching the product back on.
If the compressor inlet temperature and the compressor out-
let temperature are below -15 °C, the compressor does not
start up.
If the temperature measured at the compressor outlet is
higher than the permissible temperature, the compressor
is switched off. The permissible temperature depends on the
evaporation and condensation temperature.
The pressure in the heating circuit is monitored using a pres-
sure sensor. If the pressure falls below 0.5 bar, a fault shut-
down occurs. If the pressure rises to above 0.7 bar, the fault
is reset again.
The pressure in the heating circuit is protected using an ex-
pansion relief valve. The load relief occurs at 2.5 bar.
The product is equipped with an automatic air vent. This
must not be sealed.
The heating circuit's circulation water volume is monitored
using a flow rate sensor. If no flow rate can be detected
when there is a heat demand when the circulation pump is
running, the compressor does not start up.
If the heating water temperature falls below 4 °C, the pro-
duct's frost protection function is automatically activated as
the heating pump is started.
4 Protective zone
4.1 Protective zone
The product contains R290 refrigerant. Note that this refri-
gerant has a higher density than air. In the event of a leak,
escaping refrigerant may collect near the ground.
The refrigerant must not collect in any way that may lead
to a dangerous, explosive, suffocating or toxic atmosphere.
The refrigerant must not get inside the building via building
openings. The refrigerant must not collect in grooves.
A protective zone is defined around the product. There must
be no windows, doors, light shafts, cellar entrances, escape
hatches, flat-roof windows or ventilation openings in the pro-
tective zone.
There must be no ignition sources, such as plug sockets,
light switches, lamps, electrical switches or other permanent
ignitions sources, in the protective zone.
The protective zone must not extend to adjacent buildings or
public traffic areas.
In the protective zone, you are not permitted to make any
subsequent structural alterations which infringe the stated
rules for the protective zone.

20 Installation and maintenance instructions 0020330792_00
4.1.1 Protective zone for ground installation on
the premises
A
A 1000 mm
Dimension A is a clearance around the product.
4.1.2 Protective zone for ground installation in
front of a building wall
C
D
A
B
A 2100 mm
B 3100 mm
C 200 mm/250 mm
D 1000 mm
Dimension C is the minimum clearance that must be main-
tained to the wall (→Section 5.4).
4.1.3 Protective zone for ground installation in a
building corner
A
B
C
D
E
F
G
A 2100 mm
B 2600 mm
C 200 mm/250 mm
D 500 mm
E 1000 mm
F 500 mm
G 1800 mm
The right-hand corner of the building is shown here. Dimen-
sions C and D are the minimum clearances that must be
maintained to the wall (→Section 5.4). Dimension D varies
for the left-hand corner of the building.