Vaillant VR 66/2 User manual

Control Centre
VR 66/2
Installation instructionsen
0020140122_04 / 012023 / Subject to technical modifi cations

2Installation instructions 0020140122_04
Contents
1 Notes on the installation instructions ................3
1.1 Symbols used .........................................................3
1.2 Observe other applicable documents .....................3
1.3 Storing documents ..................................................3
1.4 Validity of the instructions .......................................3
2 Safety .....................................................................4
2.1 General safety advices ...........................................4
2.1.1 Danger to life by electric shock ..............................4
2.1.2 Danger to life by escaping gas ...............................4
2.1.3 Danger to life by escaping flue gases due to
unlocked openings ..................................................4
2.1.4 Danger to life due to missing or not properly
working safety devices............................................4
2.1.5 Danger of scalding due to the hot water! ...............4
2.1.6 Danger due to improper use ...................................4
2.1.7 Risk of material damage by additives in the
heating water ..........................................................4
2.1.8 Risk of material damage caused by unsuitable
tools ........................................................................4
2.1.9 Risk of structural damages by escaping water .......4
2.2 Intended use ...........................................................4
2.3 Rules and regulations .............................................5
2.3.1 List of relevant standards for Great Britain and
Ireland .....................................................................5
2.3.2 Benchmark ..............................................................5
2.4 CE label ..................................................................5
3 Description of the product ...................................6
3.1 Product Overview ...................................................6
3.2 Product structure ....................................................6
3.2.1 Monozone operation mode .....................................6
3.2.2 Priorities are defined as follows: .............................6
3.2.5 Multizone operation mode ....................................10
3.3 Type designation and serial number.....................14
3.4 Data plate description ...........................................14
4 Mounting and installation ..................................15
4.1 Preparing the mounting and installation ...............15
4.1.1 Considering the product location ..........................15
4.2 Mounting the product ............................................15
4.2.1 Opening the VR 66/2 ............................................15
4.2.2 Wall-mounting of the product ................................15
4.3 Electrical Installation .............................................16
4.3.1 Description of connections....................................16
4.3.2 Main board ............................................................17
5 Commissioning ...................................................17
5.1 Filling.....................................................................17
5.1.1 Boiler .....................................................................17
5.1.2 Heating circuit .......................................................17
5.2 Venting ..................................................................17
5.2.1 Boiler .....................................................................17
5.2.2 Heating circuit adjustement ..................................17
5.3 Switching on .........................................................17
5.4 Multizone specific adjustment ...............................17
5.5 Restart and check .................................................17
6 User information .................................................17
7 Maintenance ........................................................18
7.1 Trouble-shooting ...................................................18
7.1.1 Fault diagnosis
......................................................18
7.2 Main supply cable .................................................18
8 Decommissioning ...............................................19
9 Recycling and disposal ......................................19
10 Customer service ................................................19
11 Technical data .....................................................19

Installation instructions 0020140122_04 3
1 Notes on the installation instructions
1.1 Symbols used
The symbols used in the text are explained below:
Symbol Explanation
iSymbol that denotes useful tips and information
> Symbol for a required action
The warning notes are classified in accordance with the
severity of the possible danger using the following warning
signs and signal words.
Warning sym-
bol Signal word Explanation
aDanger Immediate risk of death or
risk of severe personal injury.
eDanger Risk of death from electric
shock.
aWarning Risk of minor personal injury.
bCaution Risk of material or
environmental damage.
1.2 Observe other applicable documents
>Observe absolutely all operating and installation instruc-
tions enclosed with the product, for the various parts and
components of the system.
1.3 Storing documents
>Pass these instructions and all other applicable docu-
ments to the system user.
The system user should retain these instructions so that
they are available when required.
1.4 Validity of the instructions
These instructions apply exclusively to:
Type designation Article number
VR 66/2 0020135785

4Installation instructions 0020140122_04
aa 2 Safety
All electrical work performed on the equipment must be car-
ried out by a qualified engineer or Vaillant Group Service
engineer.
This equipment must only be installed by a qualified engi-
neer, to ensure that the applicable regulations and rules are
adhered to.
When work on the appliance is completed, perform an oper-
ational test and check for safety in accordance with
BS EN 7671.
2.1 General safety advices
>Before reading this chapter, also read the general safety
advice of the operating instructions.
2.1.1 Danger to life by electric shock
Touching live connections can cause serious personal
injury.
>Before carrying out any work on the product, switch off
the power supply.
>Secure the power supply against being switched on
again.
2.1.2 Danger to life by escaping gas
Incorrect installation can cause leakages and explosion.
>Make sure there are no stresses in the gas line.
>Correctly position the seals.
>Observe the legal directives and the local regulations for
gas supply companies.
2.1.3 Danger to life by escaping flue gases due
to unlocked openings
Flue gases can escape through openings in the flue pipe.
Inspection chambers in the flue gas pipe can be opened.
>Open inspection chambers only if you are a competent
person.
Close all inspection chambers before start-up.
2.1.4 Danger to life due to missing or not
properly working safety devices
Missing safety devices can cause life-threatening scalding
and other injuries, for example by burst pipes.
The information contained in this document do not show all
schemes required for a professional installation of safety
devices.
>Install the necessary safety devices in the system.
>Inform the user about the function and location of safety
devices.
>Observe the relevant national and international laws,
standards and guidelines.
>The appliance is not to be used by persons (including
children) with reduced physical, sensory or mental capa-
bilities, or lack of experience and knowledge, unless they
have been given supervision or instruction.
>Children being supervised not to play with the appliance.
2.1.5 Danger of scalding due to the hot water!
>There is a danger of scalding at the hot water draw-off
points if the hot water temperatures are higher than
60°C. Young children and elderly persons are particularly
at risk, even at lower temperatures.
>Select the temperature so that nobody is at risk.
>Explain to the user how to select the best temperature
taking into account the risk of scalding and the risk of
legionella.
2.1.6 Danger due to improper use
Nonprofessional work on the product can cause damage to
the installation and as a consequence even personal injury.
>Only work on the product if you are a competent person.
2.1.7 Risk of material damage by additives in the
heating water
Frost and corrosion protection agents can cause changes
to seals, noise during heating mode and may lead to other
consequential damage.
>Do not use any unsuitable frost or corrosion protection
agents.
2.1.8 Risk of material damage caused by
unsuitable tools
The use of unsuitable tools or improper use thereof may
cause damage, such as gas or water leaks.
>When tightening or loosening threaded connections,
always use suitable opened spanners, but do not use
pipe wrenches, extensions, etc.
2.1.9 Risk of structural damages by escaping
water
Incorrect installation can cause leakages.
>Make sure there are no stresses in the hydraulic lines.
>Correctly position the seals.
2.2 Intended use
The product is a state-of-the-art product which has been
constructed in accordance with recognised safety regula-
tions. Nevertheless, there is still 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 intended as a heating appliance for sealed
central heating installations (heating / cooling and hot
water) to consume a minimum of energy to optimize the
energy bill.
Intended use includes the following:
– observing the included operating, installation and mainte-
nance instructions for this product and any other parts
and components of the system
– installing and fitting the product in accordance with the
product and system approval
– complying with all of the inspection and maintenance
conditions listed in the instructions.

Installation instructions 0020140122_04 5
aa
It will be necessary to install the unit in a location where it
will not be exposed to moisture or water splashes. Observe
the electrical protection (IP) contained in the technical data.
Any other use than the use described in the instructions at
hand or any use extending the described use is not
intended.
Any direct commercial or industrial use is also deemed to
be improper.
2.3 Rules and regulations
2.3.1 List of relevant standards for Great Britain
and Ireland
>Observe the national regulations, standards, directives,
ordinances and laws.
You can find a list of relevant standards at:
www.vaillant.co.uk/standards
2.3.2 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 Build-
ing Regulations. The Benchmark Checklist can be used to
demonstrate 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
2.4 CE label
The CE marking shows that the products comply
with the basic requirements of the applicable
directives as stated on the declaration of con-
formity.
The declaration of conformity can be viewed at the manu-
facturer’s site.

6Installation instructions 0020140122_04
3 Description of the product
3.1 Product Overview
The control centre provides a system solution which permits
eBUS controllers to be combined with room thermostats,
valves, multizone heating and domestic hot water cylinder
systems. There are 3 functional modes that can be selected
with the rotary switch:
– Multizone mode (position 0) with VR 66/2 functions in
combination with VRT 350
– Multizone mode (position 2) with VR 66/2 functions in
combination with one VRT 380 and one VR 92
– Monozone mode (position 1) with VR65 functions.
230V~ CYL.
21
DHW
CH1 CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
0
1
Key
1 Rotary switch
3.2 Product structure
3.2.1 Monozone operation mode
The Monozone operation mode is compatible with:
– ebus control range
– system and open vent boiler
It allows the controller to communicate with the traditional
230 V zone valves and DHW storage cylinder. Information
about the heat required by the cylinder is communicated to
the heating appliance. The heating appliance (boiler) then
decides whether a hot water request has to be fulfilled and
sends a signal to position the 230 V zone valves.
The initial start-up of the control centre is carried out
together with the initial start-up of the boiler.
i If a VR65 is replaced by a VR 66/2 it has to be
set on monozone mode.
3.2.2 Priorities are defined as follows:
Value of
diagnostic
code d.70
Meaning
0
Hot water priority
– The 3-port valve is in the heating or hot water
position depending on the operating mode.
– With 2-port valves, either the DHW valve or the
CH valve is open, both valves are closed on
standby.
1
Enable mid position
– The 3-port valve is in the mid position for simul-
taneous heating and hot water request, or in the
heating or hot water position, depending on the
operating mode.
– With 2-port valves, both valves are open during
simultaneous heating and hot water request.
Otherwise, only one valve is always open and
both valves are closed on standby.
2
Only heating mode (only for test operation!)
– Only the CH valve is activated.
NOTE: Factory settings of boiler = 0 : hot water priority.

Installation instructions 0020140122_04 7
3.2.3 Monozone mode: Open vent or system boiler with DHW cylinder, 3-Port Valve
9a
BUS BUS BUS BUS
BUS BUS BUS BUS BUS BUS BUS BUS BUS
10e
12f
2
DHW 3
9k
BUS BUS BUS BUS
1
1
12
9k
12f
3
8c
8f
5
DHW
1a
3
2
12f
38
230V ~
230 V~
3
1
230 V~
3
2
Key
1 Heat generator
1a Back-up heater for domestic hot water
5 Monovalent domestic hot water cylinder
8c Safety assembly for the potable water connection
8f Expansion vessel for potable water
9a Single-room temperature control valve (thermostatic/motor-
ised)
9k 3-port mixing valve
10e Line strainer with magnetite separator
12 System control
12f VR 66/2 control centre
b38 If a thermostat shall be used, instead of the DHW tempera-
ture sensor; remove the DHW temperature sensor, mount
the thermostat, and connect the thermostat on clamp ‘CYL’.

8Installation instructions 0020140122_04
230 V~ 0 ...24 V
12f
VR 66
-
NTC
BUS
- +
2 1
DHW OFF
N L
DHW ON
N L
CH1
N L
230V~
N L
230 V~230 V~
CYL
2 1
CH2
CYL CH1
DHW ON DHW OFF / CH2
BUS NTC
1
1
12
DHW
M
9k
38
230 V~
230 V~ 0 ...24 V
L
N
X1
230 V~
X12
L
N
L
N
BUS
24V=
RT
- +
Burn.
off
X13
Opt.2
X16
Opt.1
X100
X41
X40 X51 X35 X31
X32
0( )
0( )
DCF
RF
AF
FB
1
ecoTEC plus
X36
3-port valve electrical connections:
>Connect the live wire (white or brown) of the valve to the
“L” of the CH1 connector.
>Connect the earth wire (yellow/green) of the valve to the
earth of the DWH ON connector.
>Connect the neutral wire (blue) of the valve to the “N” of
the DWH ON connector.
>Connect the live wire (orange) of the valve to the “L” of
the DWH ON connector.
>Connect the live wire (grey) of the valve to the “L” of the
DWH OFF CH2.
b38 If a thermostat shall be used, instead of the DHW tempera-
ture sensor; remove the DHW temperature sensor, mount
the thermostat, and connect the thermostat on clamp ‘CYL’.

Installation instructions 0020140122_04 9
3.2.4 Monozone mode: Open vent or system boiler with DHW cylinder, two 2-Port Valves
9a
BUSBUSBUSBUSBUSBUSBUSBUS
12
BUS BUS BUS
M
312f
M
312f
9e
9b
12f
9b
3
9e
BUSBUS
32
BUS BUS
10e
1
1
2
DHW
8c
8f
5
DHW
1a
3
2
230V ~
12f
38
1
230 V~
3
2
17
230 V~
3
12q 230 V~
3
WLAN
LAN
Key
1 Heat generator
1a Back-up heater for domestic hot water
5 Monovalent domestic hot water cylinder
8c Safety assembly for the potable water connection
8f Expansion vessel for potable water
9a Single-room temperature control valve (thermostatic/motor-
ised)
9b Zone valve
9e Diverter valve for potable water
10e Line strainer with magnetite separator
12 System control
12f VR 66/2 control centre
12q Internet gateway (optional)
b17 Optional component
b38 If a thermostat shall be used, instead of the DHW tempera-
ture sensor; remove the DHW temperature sensor, mount
the thermostat, and connect the thermostat on clamp ‘CYL’.

10 Installation instructions 0020140122_04
12
230 V~ 0 ...24 V
12f
VR 66
NTCBUS
- +
2 1
DHW OFF
N L
DHW ON
N L
CH1
N L
230V~
N L
230 V~
230 V~
CYL
2 1
CH2
CYL CH1
DHW ON DHW OFF / CH2 BUS NTC
1
1
M
9b
MM
9e
M

DHW
230 V~
230 V~ 0 ...24 V
L
N
X1
230 V~
X12
L
N
24V=
RT
Burn.
L
off
N
BUS
- +
X13
Opt.2
X16
Opt.1
X100
X41
X40 X51 X35 X31
X32
0( )
0( )
DCF
RF
AF
FB
1
ecoTEC plus
X36
38
12q
BUS PWR LAN
VR 921
230 V~
b38 If a thermostat shall be used, instead of the DHW tempera-
ture sensor; remove the DHW temperature sensor, mount
the thermostat, and connect the thermostat on clamp ‘CYL’.
3.2.5 Multizone operation mode
The Multizone operation mode is compatible with:
– VRT 350 (using rotary switch position 0) or
– VRT 380 and VR 92 (using rotary switch position 2)
– system, combi and open vent boiler
The information about the heating or hot water demand is
sent by the room thermostat via the control centre to the
boiler. The VR 66/2 then decides if the hot water demand
needs to be fulfilled and drives the valves.
In this way, the boiler can store different target tempera-
tures for heating and hot water modes.
i The multizone mode is only compatible with
VRT 350 or VRT 380 combined with VR 92. No
other room thermostats are compatible.
The multizone mode will NOT support weather
compensation and cannot be used on Y plan
systems with three port motorised valves.
The standard installation for multizone mode is character-
ised by:
– 2 port valves for zoning,
– 2 VRT 350 programmable wired room thermostats or
– 1 VRT 380 room thermosthat combined with 1 VR 92,
– heating zones and DHW cylinder cannot operate in par-
allel.
Priorities are defined as follows:
Priority levels Function
1 Domestic hot water
2 Central heating

Installation instructions 0020140122_04 11
3.2.6 Multizone mode : Open vent or system boiler with DHW cylinder
BUS
BUS
BUS
BUSBUSBUS
BUS
BUS
BUS BUS BUS
M
312f
9e
12f
9b1
3
9e
BUS
3
2
2
2
2
DHW
BUS BUS
8c
8f
5
DHW
1a
3
2
230V ~
12f
38
9b2
3
10e
M
3
M
3
9b29b1
12 12a
9a 9a
12f 12f
1
230 V~
3
2
230 V~
3
12q 230 V~
3
WLAN
LAN 17
BUSBUS
Key
1 Heat generator
1a Back-up heater for domestic hot water
5 Monovalent domestic hot water cylinder
8c Safety assembly for the potable water connection
8f Expansion vessel for potable water
9a Single-room temperature control valve (thermostatic/motor-
ised)
9b Zone valve
9e Diverter valve for potable water
10e Line strainer with magnetite separator
12 System control
12a Remote control
12f VR 66/2 control centre
12q Internet gateway (optional)
b17 Optional component
b38 If a thermostat shall be used, instead of the DHW tempera-
ture sensor; remove the DHW temperature sensor, mount
the thermostat, and connect the thermostat on clamp ‘CYL’.

12 Installation instructions 0020140122_04
12
230 V~ 0 ...24 V
12f
VR 66
NTCBUS
- +
2 1
DHW OFF
N L
DHW ON
N L
CH1
N L
230V~
N L
230 V~
230 V~
CYL
2 1
CH2
CYL CH1
DHW ON DHW OFF / CH2 BUS NTC
2
2
M
9b1
M M
9e
M

DHW
230 V~
230 V~ 0 ...24 V
L
N
X1
230 V~
X12
L
N
L
N
BUS
24V=
RT
- +
Burn.
off
X13
Opt.2
X16
Opt.1
X100
X41
X40 X51 X35 X31
X32
0( )
0( )
DCF
RF
AF
FB
1
ecoTEC plus
X36
M
9b2
M38
12q
BUS PWR LAN
VR 921
230 V~
12a
b38 If a thermostat shall be used, instead of the DHW tempera-
ture sensor; remove the DHW temperature sensor, mount
the thermostat, and connect the thermostat on clamp ‘CYL’.

Installation instructions 0020140122_04 13
3.2.7 Multizone mode with combi boiler
BUS
BUS
BUS
BUS
BUSBUS
BUSBUS
BUS BUS BUS
12f
9b2
BUS
3
2
2
2
BUS
9b1
3
10e
M
3
M
3
9b29b1
12 12a
9a 9a
12f 12f
230 V~
3
12q 230 V~
3
17
1
230 V~
3
2
M
BUS
BUS
WLAN
LAN
Key
1 Heat generator
9a Single-room temperature control valve (thermostatic/motor-
ised)
9b Zone valve
10e Line strainer with magnetite separator
12 System control
12a Remote control
12f VR 66/2 control centre
12q Internet gateway (optional)
b17 Optional component

14 Installation instructions 0020140122_04
12
230 V~ 0 ...24 V
12f
VR 66
NTCBUS
- +
2 1
DHW OFF
N L
DHW ON
N L
CH1
N L
230V~
N L
230 V~
230 V~
CYL
2 1
CH2
CYL CH1
DHW ON DHW OFF / CH2 BUS NTC
2
2
9b1
M
230 V~
230 V~ 0 ...24 V
L
N
X1
230 V~
X12
L
N
L
N
BUS
24V=
RT
- +
Burn.
off
X13
Opt.2
X16
Opt.1
X100
X41
X40 X51 X35 X31
X32
0( )
0( )
DCF
RF
AF
FB
1
ecoTEC plus
X36
9b2
M
12q
BUS PWR LAN
VR 921
230 V~
12a
3.3 Type designation and serial number
Data plate location:
1
3.4 Data plate description
The data plate certifies the country where the product is
intended to be installed.
The data plate contains the following data:
Abreviation/symbol Description
Brand and Product name Vaillant VR 66/2
Model Product article number
V/Hz Hz Voltage / Frequency
T Temperature range
Serial-no Product serial number
VA Power Consumption

Installation instructions 0020140122_04 15
4 Mounting and installation
i All the dimensions shown of the illustrations are
expressed in millimetres (mm).
4.1 Preparing the mounting and installation
4.1.1 Considering the product location
Before choosing a site for the appliance, carefully read the
safety warnings and instructions in the user guide and
installation manual.
>Explain these requirements to the appliance user.
>Take all necessary precautions.
Install the system:
– in a room protected from frost,
– in a convenient location, accessible for wiring and servic-
ing.
Do not install the control centre:
– close to heat sources such as radiators, chimney walls,
televisions, direct sunlight,
– above a cooking device capable of generating steam and
grease,
– in a room with a lot of dust or with a corrosive atmos-
phere.
b Caution!
These pipes can become very hot which
will damage the cables or the system.
>The electrical cables must not be
attached to or in contact with the hydrau-
lic pipes.
1500
174
272
52
4.2 Mounting the product
4.2.1 Opening the VR 66/2
A
B
>Unscrew (A) the screw securing the housing cover.
>Pull (B) the housing cover forwards.
4.2.2 Wall-mounting of the product
The control centre is designed to be attached to a wall near
the main tank inside a dwelling.
235
3
3
4
1
1
2
2
Key
1 Screws
2 Attachment holes
3 Holes
4 Plugs
>Determine the position depending on the requirements of
the preceding chapter: “Appliance location”.

16 Installation instructions 0020140122_04
4.3 Electrical Installation
e Danger!
Incorrect installation can cause electric
shock or appliance damage.
The electrical connection of the appliance
must be made only by a qualified engineer.
>Ensure system is electrically isolated.
Protect the electrical installation by fol-
lowing the guidance indicated in the
“Technical data” chapter.
e Danger!
>The length of the power supply cable
must not exceed 10 metres.
>The electrical installation in the dwelling must permit the
power supply to the equipment to be isolated by a dou-
ble pole isolation switch and be fused. The double pole
isolation switch must incorporate a gap of 3 mm between
the contacts.
>Use a power cable suitable for the main connection, min-
imum 1.5 mm. If the cable is damaged, it must be
replaced by a qualified engineer.
The external wiring must be earthed, with correct polarity
and in accordance with current standards.
The manufacturer declines any responsibility for damages
to persons or others caused by the incorrect installation of
the appliance earthing. This includes failure to comply with
current standards.
b Caution!
These pipes can become very hot which
will damage the cables or the system.
>The electrical cables must not be
attached to or in contact with the hydrau-
lic pipes.
4.3.1 Description of connections
All of the internal connections are made directly to the cir-
cuit board.
2
3
1
Key
1 Cable clamp
2 Divisible wire grommet
3 Separating high and low voltage
The circuit board connectors are divided into two parts. The
left part accepts a 230 V power supply whereas the right
part is used for 24 V power.
230V connectors (High voltage)
230V~ CYL.
21
DHW
CH1 CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
230V~ CYL.
21
DHW
CH1 CH2
ON
DHW
OFF
1 2 3 4 5
Key
1 230 V supply connector (3 pins: earth / neutral / live)
2 Cylinder thermostat connector (2 pins)
3 Heating zone 1 valve (3 pins: earth/neutral/ live)
4 DHW valve ON (3 pins: earth / neutral / live)
5 DHW valve OFF - Heating zone 2 valve (3 pins: earth/neu-
tral/ live)
24V connectors (low voltage)
230V~ CYL.
21
DHW
CH1 CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
1
2
-
+
BUS NTC
1 2
Key
1 eBUS connector (2 pins)
2 NTC connector (2 pins)

Installation instructions 0020140122_04 17
4.3.2 Main board
20 mm max.
2
1
Key
1 Electrical wires
2 Casing
When you connect the electrical wires to a connector on the
main electronic board:
>Keep a distance of a maximum of 20 mm between con-
nector and the start of the insulation (2).
>If single core wires are used (1) ensure that they are
wrapped together in an insulating sheath.
>Fix the cables in the cable-clamps on the unit.
5 Commissioning
The commissioning should be carried out by a competent
person approved at the time by the Health and Safety Exec-
utive and in accordance with the current issue of BS6798.
>Completely open all the radiator thermostatic valves in
the rooms where the room thermostats were been
installed.
5.1 Filling
5.1.1 Boiler
Commission the boiler according to the instructions of its
installation manual.
>Refer to the installer manual.
5.1.2 Heating circuit
>Manually open the different heating circuit valves.
5.2 Venting
5.2.1 Boiler
Commission the boiler according to the instructions of its
installation manual.
>Refer to the installer manual.
5.2.2 Heating circuit adjustement
Venting of the heating circuit enables the purging of any air
in the heating circuit (valves still manually opened).
>Open the different heating circuit air vent.
b Caution!
>When venting is complete, close the dif-
ferent heating circuit air vent and valves.
5.3 Switching on
>Turn on all the appliances that make up the installation
(see the installation manual(s)). Use the following order:
– Control centre
– Boiler
5.4 Multizone specific adjustment
In case of multizone mode selection (rotary switch in pos
0), the pairing must be made between the room thermo-
stat(s) and control centre in the system heating (one after
the other).
>Follow the install assistant of the room thermostat “zone
1”.
>Consult the installation manual of the room thermostat in
order to carry out the operation.
>Repeat the operation with the room thermostat “zone 2”
5.5 Restart and check
>Check if all settings have been saved by switching the
system off and then on to ensure that any adjustments
operate correctly and check that the appliances operate
safely.
>Check if the system answers correctly to a demand:
– issue a heating demand for the heating zone 1
– issue a heating demand for the heating zone 2 (if
multizone mode is selected)
– issue a domestic hot water demand (if DWH tank is
connected)
6 User information
At the end of the installation, the installer must:
– explain the operation of the appliance and its safety
devices to the user, if necessary provide a demonstration
and answer any questions;
– give the user all the required documentation,
– fill in the documents where necessary;
– advise the user of the precautions necessary to prevent
damage to the system, appliance and the building;
– remind the user to service the appliance annually.

18 Installation instructions 0020140122_04
7 Maintenance
7.1 Trouble-shooting
7.1.1 Fault diagnosis
The following checks should be performed before proceed-
ing onto specific diagnostics:
– Ensure that the control centre has not been discon-
nected from the electricity supply and that it is connected
correctly.
– Ensure that all installation’s appliances are available.
– Check the functioning of external regulatory devices
(room thermostat(s).
i The rectification of faults described in this chap-
ter should be carried out by a qualified engineer
and if needed by the After Sales Service.
230V~ CYL.
21
DHW
CH1 CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
2
1
3
Key
1 Fuse
2 Green LED, power supply
3 Red LED flashes, fault
Fault Possible cause Solution
Green LED perma-
nently off
No 230 V power
supply or the fuse
in the appliance is
faulty
Check that the main
voltage cable is
connected correctly.
Check the domestic
fuse for the 230 V
supply and re-con-
nect the power
supply. Replace the
main supply fuse in
the control centre
(see technical
data).
Red LED flashes
quickly (2 Hz,
2 flashes/second)
Short circuit of the
connected tempera-
ture sensor (NTC)
in the cylinder
Check the cable of
the temperature
sensor (NTC) for
damage. Replace
the temperature
sensor (NTC) in the
cylinder.
Red LED flashes
slowly (0,5 Hz,
1 flash/ 2 seconds)
Communications
error with the eBUS
boiler.
Check that the boil-
er’s eBUS cable is
connected correctly
and not damaged.
Check that the
boiler is turned on.
Heating zone
valves not operating
Valve disconnected.
Valve doesn’t open.
Check the room
thermostat(s) com-
patibility and con-
nections. Check the
valve connections.
Check the room
thermostat(s) pair-
ing. Ensure that
there is no interrup-
tion to the electricity
supply and that the
control centre is
properly connected
and turned on.
DHW valve not
operating
Fault domestic hot
water cylinder
Cylinder dual ther-
mostat discon-
nected. The tem-
perature sensor is
defective or discon-
nected.
Check the cylinder
dual thermostat and
temperature con-
nections. Check the
sensor’s resistance.
Ensure that there is
no interruption to
the electricity sup-
ply and that the
control centre is
properly connected
and turned on.
7.2 Main supply cable
e Danger!
>The main supply cable must be replaced
by a qualified and competent electrician.
>If the main supply cable is damaged, replace it refering
to the chapter “Electrical connection”.

Installation instructions 0020140122_04 19
8 Decommissioning
>Switch off the product.
>Isolate the product from the power mains.
>De-install the product.
>Recycle or dispose the product and its components (see
chapter 9).
9 Recycling and disposal
This product is an electrical or electronic unit within the con-
text of EU Directive 2012/19/EU. The unit was developed
and manufactured using high-quality materials and compo-
nents. These can be recycled and reused.
Find out about the regulations that apply in your country
regarding the separate collection of waste electrical or elec-
tronic equipment. Correctly disposing of old units protects
the environment and people against potential negative
effects.
>Dispose of the packaging correctly.
>Observe all relevant regulations.
Disposing of the product
If the product is labelled with this symbol:
>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 symbol:
>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. Otherwise,
the batteries are disposed of together with the prod-
uct.
>In accordance with the legal regulations, the end user is
obligated to return used batteries.
Deleting personal data
Personal data may be misused by unauthorised third par-
ties.
If the product contains personal data:
>Ensure that there is no personal data on or in the prod-
uct (e.g. online login details or similar) before you dis-
pose of the product.
10 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.
11 Technical data
Description Unit VR 66/2
Power-supply voltage V, Hz 230, 50/60
Power consumption W 20
Contact load of output relays
(max.)
A2
Delay fuse A T 4 A/250 V
Contact voltage for DHW cylinder
thermostat
V 230
Temperature sensor (NTC) operat-
ing voltage
V5
Thermistor NTC at 25°C kOhm 2.7
eBUS connection cable gauges mm22 x 0.75
Maximum length of eBUS cable m 300
Power cable gauge mm23 x 1.5
Maximum length of power cable m 10
Dimensions :
– Height mm 185
– Length
mm 281.3
– Depth
mm 49.5
Electrical protection IP20
Electrical classification I

Manufacturer
Vaillant GmbH
Berghauser Str. 40 D-42859 Remscheid
Tel. [phone] Fax [phone]
[email protected] www.vaillant.de
© These instructions, or parts thereof, are protected by copyright and may be reproduced or distributed only with
the manufacturer’s written consent.
Subject to technical modifications.
Supplier
Vaillant Ltd
Nottingham Road Belper Derbyshire DE561JT
Telephone [phone] www.vaillant.co.uk [email protected]
0020140122_04