Vaillant VR 66/2 User manual

Installation instructions
For the competent person
GB, IE
Installation instructions
VR 66/2 Control Centre

EN
- 1 -
1 Notes on the installation instructions .................................................................................................... 2
1.1 Symbols used ................................................................................................................................. 2
1.2 Observe other applicable documents............................................................................................... 2
1.3 Storing documents.......................................................................................................................... 2
1.4 Validity of the instructions............................................................................................................... 2
2 Safety ................................................................................................................................................... 2
2.1 General safety advices .................................................................................................................... 2
2.2 Intended use................................................................................................................................... 3
2.3 Rules and regulations...................................................................................................................... 3
2.4 CE label........................................................................................................................................... 4
3 Description of the product..................................................................................................................... 4
3.1 Product Overview ............................................................................................................................ 4
3.2 Product structure ............................................................................................................................ 5
3.3 Type designation and serial number .............................................................................................. 11
3.4 Data plate description................................................................................................................... 11
4 Mounting and installation ................................................................................................................... 11
4.1 Preparing the mounting and installation........................................................................................ 11
4.2 Mounting the product.................................................................................................................... 11
4.3 Electrical Installation..................................................................................................................... 12
5 Commissioning ................................................................................................................................... 13
5.1 Filling ........................................................................................................................................... 13
5.2 Venting ......................................................................................................................................... 13
5.3 Switching on................................................................................................................................. 13
5.4 Multizone specific adjustment....................................................................................................... 13
5.5 Restart and check.......................................................................................................................... 13
6 User information ................................................................................................................................. 14
7 Maintenance ....................................................................................................................................... 14
7.1 Trouble-shooting........................................................................................................................... 14
7.2 Main supply cable ......................................................................................................................... 14
8 Decommissioning................................................................................................................................ 15
9 Recycling and disposal........................................................................................................................ 15
9.1 Recycle the packaging................................................................................................................... 15
9.2 WEEE: Recycle or dispose the product and its components............................................................. 15
10 Guarantee and customer service.......................................................................................................... 15
10.1 Vaillant warranty ........................................................................................................................... 15
10.2 Vaillant Service ............................................................................................................................. 15
11 Technical data..................................................................................................................................... 15
TABLE OF CONTENTS

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INTRODUCTION
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 sig-
nal words.
Warning symbol 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 instructions
enclosed with the product, for the various parts and compo-
nents of the system.
1.3 Storing documents
>Pass these instructions and all other applicable documents 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:
Liste type
Type designation Article number
VR 66/2 0020135785
2 Safety
All electrical work performed on the equipment must be carried
out by a qualified engineer or Vaillant Group Service engineer.
This equipment must only be installed by a qualified engineer, to
ensure that the applicable regulations and rules are adhered to.
When work on the appliance is completed, perform an opera-
tional test and check for safety in accordance with BS EN 7671.
2.1 General safety advices
>Before to read 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. Inspec-
tion 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, stand-
ards and guidelines.
>The appliance is not to be used by persons (including chil-
dren) with reduced physical, sensory or mental capabilities, or
lack of experience and knowledge, unless they have been
given supervision or instruction.
>Children being supervised not to play with the appliance.

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INTRODUCTION
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 conse-
quential 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 con-
structed in accordance with recognised safety regulations. Never-
theless, 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 con-
sume 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 prod-
uct and system approval
– complying with all of the inspection and maintenance condi-
tions listed in the instructions.
It will be necessary to install the unit in a location where it will
not be exposed to moisture or water splashes. Observe the elec-
trical 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 Statutory requirements
Installation of this appliance falls within the scope of the Build-
ing egulations 2010 (Part G). This requires that the installation of
an unvented system should be notified to the local authority
Building Control Department and the work must be carried out by
a competent person as defined in the approved document G3.
Where no British Standards exists, materials and equipment
should be fit for their purpose and of suitable quality and work-
manship.
The installation of this control centre must be carried out by a
competent person approved at the time by the Health and Safety
Executive and in accordance with the rules in force in the coun-
tries of destination.
Manufacturer’s instructions must not be taken as overriding stat-
utory requirements.
During the installation and activation of the control centre, the
decrees, directives, technical regulations, standards and clauses
hereafter must be complied with in the versions that are currently
in force.
– IEC 60730-2-9 Automatic electrical controls for household and
similar use: Particular requirements for temperature sensing
controls
– IEC 60730-1 Automatic electrical controls for household and
similar use: Common requirements
– IEC 60335-1 Specification for safety of household and similar
electrical appliances
– Directive on the restriction of the use of certain hazardous
substances in electrical and electronic equipment (2002/95/
EC)
– Regulation concerning the Registration, Evaluation, Authorisa-
tion and Restriction of Chemicals (REACH, No. 1907/2006)
In GB, the installation of the control centre must comply with the
requirements of the current issue of BS6798 and be carried out
by a competent person approved at the time by the Health and
Safety Executive and as described in the following regulations:
– The manufacturer’s instructions supplied.
– The Gas Safety (Installation and Use) Regulations.
– The appropriate Building Regulations (UK), The Building Regu-
lations (Scotland), The Building Regulations (Northern Ire-
land).
– The Water Supply (water fittings) Regulations 1999 and water
byelaws 2000, Scotland.
– The Health and Safety at Work Act, Control of Substances Haz-
ardous to Health (COSHH).

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INTRODUCTION
– Any electrical work must conform to BS7671 and part P of the
building regulations where applicable.
Where no specific instructions are given, reference should be
made to the relevant British Standard Code of Practice.
In IE, the installation must be carried out by a competent person
approved at the time by the Health and Safety Executive and
installed in accordance with the current edition of I.S.813
“Domestic Gas Installations”, the current Building Regulations
and reference should be made to the current ETCI rules for Elec-
trical Installation.
GB: the following Codes of Practice apply: BS4814, BS6798,
BS5440 Part 1 and 2, BS5546 Part 1, BS5449, BS6891, BS6700,
BS7074 Part 1 and 2, BS7593, BS7671.
IE: I.S.813, BS5546, BS 5449, BS 7074, BS 7593.
NOTE: For further information, see the current issue of the Build-
ing Regulations, approved document L1 ( in the UK) and the fol-
lowing current issues of:
1) Central heating system specification (CheSS) and
2) Controls for domestic central heating system and hot water.
BRECSU.
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 manu-
facturer’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 Regulations.
The Benchmark Checklist can be used to demonstrate compliance
with Building Regulations and should be provided to the cus-
tomer for future reference.
Installers are required to carry out installation, commissioning
and servicing work in accordance with the Benchmark Code of
Practice which is available from the Heating and Hotwater Indus-
try Council who manage and promote the Scheme.
Visit www.centralheating.co.uk for more information.
2.3.2 Domestic Hot Water
All domestic hot water circuits, connections, fittings must be in
accordance with the relevant standards and water supply regula-
tions.
2.3.3 Electrical Supply
The control centre MUST be earthed. All system components shall
be of an approved type and all wiring to current I.E.E. wiring reg-
ulations. External wiring must be correctly earthed, polarised and
in accordance with the relevant standards.
In GB, this is BS 7671.
In IE, this is the current edition of ETCI rules.
The control centre MUST be connected to a permanent 230 V ac,
50 Hz supply.
2.4 CE label
The CE mark indicates that the products described in these
instructions are in compliance with the following directives:
– European Directive Num. 2004-108 of the European Parlia-
ment and the Council regarding electromagnetic compatibility
– European Directive Num. 2006-95 of the European Parliament
and the Council regarding low voltage.
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 combi-
nation with VRT 350
– Multizone mode (position 2) with VR 66/2 functions in combi-
nation with one VRT 380 and one VR 92
– Monozone mode (position 1) with VR65 functions.
230V~ CYL.
21
DHW
CH1CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
0
1
Key
1 Rotary switch

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INTRODUCTION
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 posi-
tion 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.
iIf 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 simultaneous
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 simul-
taneous heating and hot water request. Otherwise, only
one valve is always open and both valves are closed on
standby.
2Only heating mode (only for test operation!)
– Only the CH valve is activated.
NOTE: Factory settings of boiler = 0 : hot water priority.

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3.2.3 Monozone mode: Open vent or system boiler with DHW cylinder, 3-Port Valve
EBUS
EBUS
1
2
-
+
BUS NTC
L N L L
16A
230V~ CYL. DHW
CH1CH2
21
BUS
16A
NL
BUS
ON
DHW
OFF
1m min.
1
2
-
+
BUS NTC
L N L L
16A
230V~ CYL. DHW
CH1CH2
21
ON
DHW
OFF
1
1
BUS
16A
NL
BUS
10
9
5
2
A
B
11
9
8
7
5
3
4
6
4
1
C
D
5
3
1
2
4
4
8
1
2
DHW cylinder with temperature sensor DHW cylinder with thermostat
Key
1 Room thermostat
2 System boiler
3 3-port valve
4 Electrical supply
5 VR 66/2 control centre
6 Bypass necessary with open vent boilers
7 Domestic hot water cylinder
8 Temperature sensor (not supplied)
9 Cylinder thermostat
10 Heating circuit
11 Overheating safety (if underfloor heating)
A Boiler circuit return
B Boiler circuit flow
C Cold water supply
D Domestic hot water outlet
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.

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3.2.4 Monozone mode: Open vent or system boiler with DHW cylinder, two 2-Port Valves
EBUS
EBUS
1
2
-
+
BUS NTC
N L N L
16A
230V~ CYL. DHW
CH1CH2
21
ON
DHW
OFF
6
4 3
5
1
2
-
+
BUS NTC
N L N L
16A
230V~ CYL. DHW
CH1CH2
21
ON
DHW
OFF
1
1
BUS
16A
NL
BUS
BUS
16A
NL
BUS
1
2
11
6
2
8
3
A
B
9
10
4
127
5
1
C
D
1m min.
9
10
1
2
6
4 3
6
DHW cylinder with temperature sensor DHW cylinder with thermostat
Key
1 Room thermostat
2 System boiler
3 DHW valve - 2-port valve
4 Heating 2-port valve
5 Electrical supply
6 VR 66/2 control centre
7 Bypass necessary with open vent boilers
8 Domestic hot water cylinder
9 Temperature sensor (not supplied)
10 Cylinder thermostat
11 Heating circuit
12 Overheating safety (if underfloor heating)
A Boiler circuit return
B Boiler circuit flow
C Cold water supply
D Domestic hot water outlet

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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 ful-
filled and drives the valves.
In this way, the boiler can store different target temperatures for
heating and hot water modes.
iThe multizone mode is only compatible with VRT 350
or VRT 380 combined with VR 92. No other room ther-
mostats are compatible.
The multizone mode will NOT support weather com-
pensation and cannot be used on Y plan systems with
three port motorised valves.
The standard installation for multizone mode is characterised 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 parallel.
Priorities are defined as follows:
Priority levels Function
1Domestic hot water
2Central heating

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3.2.6 Multizone mode : Open vent or system boiler with DHW cylinder
1
2
-
+
BUS NTC
N L N L N L
16A
230V~ CYL.
21
BUSBUS
16A
NL
BUS
DHW
CH1CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
N L N L N L
16A
230V~ CYL.
21
BUSBUS
16A
NL
BUS
DHW
CH1CH2
ON
DHW
OFF
1m min.
EBUS
EBUS
EBUS
0
02
16
15
10
10
2
12
7
A
B
5
13
613 7
6
8
8
1411
9
1
9
10
67 8 5
123 123
9
4 4
C
D
3
DHW cylinder with temperature sensor DHW cylinder with thermostat
Key
1 VRT 350 room thermostat “zone 1” or VRT 380
2 Open vent or system boiler
3 VRT 350 room thermostat “zone 2” or VR 92
(in combination with VRT 380)
4 Connection block (not supplied)
5 Temperature sensor (not supplied)
6 Heating zone 2 - 2-port valve
7 DHW valve - 2-port valve
8 Heating zone 1 - 2-port valve
9 Electrical supply
10 VR 66/2 control centre
11 Bypass necessary with open vent boilers
12 Domestic hot water cylinder
13 Cylinder thermostat
14 Overheating safety (if underfloor heating),
as far as possible or 1 m min. of cylinder connection
15 Heating circuit zone 1
16 Heating circuit zone 2
A Boiler circuit return
B Boiler circuit flow
C Cold water supply
D Domestic hot water outlet

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3.2.7 Multizone mode with combi boiler
EBUS
EBUS
EBUS
1
2
-
+
BUS NTC
N L N L
16A
230V~ CYL. DHW
CH1CH2
21
BUSBUS
16A
NL
BUS
ON
DHW
OFF
0
0
2
10
9
8
2
A
B
D
5
6
11
7
3
8
5 6
123
7
4
1
C
Key
1 VRT 350 room thermostat “zone 1” or VRT 380
2 Combi boiler
3 VRT 350 room thermostat “zone 2” or VR 92
(in combination with VRT 380)
4 Connection block (not supplied)
5 Heating zone 2- 2-port valve
6 Heating zone 1- 2-port valve
7 Electrical supply
8 VR 66/2 control centre
9 Heating circuit zone 1
10 Heating circuit zone 2
11 Overheating safety (if underfloor heating)
A Boiler circuit return
B Boiler circuit flow
C Cold water supply
D Domestic hot water outlet

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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
TTemperature range
Serial-no Product serial number
See chapter “Recycling”
See chapter “CE label”
VA Power Consumption
4 Mounting and installation
iAll 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 man-
ual.
>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 servicing.
Do not install the control centre:
– close to heat sources such as radiators, chimney walls, televi-
sions, direct sunlight,
– above a cooking device capable of generating steam and
grease,
– in a room with a lot of dust or with a corrosive atmosphere.
bCaution!
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 hydraulic 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.

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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”.
4.3 Electrical Installation
eDanger!
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 following
the guidance indicated in the “Technical
data” chapter.
eDanger!
>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 double
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, minimum
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 per-
sons or others caused by the incorrect installation of the appli-
ance earthing. This includes failure to comply with current stand-
ards.
bCaution!
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 hydraulic pipes.
4.3.1 Description of connections
All of the internal connections are made directly to the circuit
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
CH1CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
230V~ CYL.
21
DHW
CH1CH2
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/neutral/ live)

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24V connectors (low voltage)
230V~ CYL.
21
DHW
CH1CH2
ON
DHW
OFF
1
2
-
+
BUS NTC
1
2
-
+
BUS NTC
1 2
Key
1 eBUS connector (2 pins)
2 NTC connector (2 pins)
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 connector
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 Executive 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 instal-
lation 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 instal-
lation 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.
bCaution!
>When venting is complete, close the different
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 thermostat(s) and con-
trol 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 cor-
rectly 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 con-
nected)

EN
USER INFORMATION
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0020140122_03 - 12/19 - Vaillant
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 dam-
age to the system, appliance and the building;
– remind the user to service the appliance annually.
7 Maintenance
7.1 Trouble-shooting
7.1.1 Fault diagnosis
The following checks should be performed before proceeding
onto specific diagnostics:
– Ensure that the control centre has not been disconnected 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).
iThe rectification of faults described in this chapter
should be carried out by a qualified engineer and if
needed by the After Sales Service.
230V~ CYL.
21
DHW
CH1CH2
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 sup- ply or the fuse in the
appliance is faulty
Check that the main
voltage cable is con-
nected correctly. Check
the domestic fuse for
the 230 V supply and
re-connect 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 tempera-
ture 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 boiler’s
eBUS cable is con-
nected 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) compati-
bility and connections.
Check the valve con-
nections. Check the
room thermostat(s)
pairing. Ensure that
there is no interruption
to the electricity supply
and that the control
centre is properly con-
nected and turned on.
DHW valve not oper-
ating
Fault domestic hot
water cylinder Cylinder dual ther- mostat discon-
nected. The tempera-
ture sensor is defec-
tive or disconnected.
Check the cylinder dual
thermostat and tem-
perature connections.
Check the sensor’s
resistance. Ensure that
there is no interruption
to the electricity supply
and that the control
centre is properly con-
nected and turned on.
7.2 Main supply cable
eDanger!
>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”.

EN
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DECOMMISSIONING
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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 chap-
ter 9).
9 Recycling and disposal
9.1 Recycle the packaging
>Sort the waste to separate those which can be recycled (car-
tons, plastics...) from those that cannot (strapping ...).
>Recycle the product packaging according to all relevant regu-
lations.
9.2 WEEE: Recycle or dispose the product and its
components
The product must be recycled under the WEEE Directive (Waste
Electrical and Electronic Equipment), which specifies:
– the selective collection of waste electrical and electronic
equipment.
– the selective systematic treatment of certain components and
substances considered as dangerous,
– the reuse, recycling and recovery of the collected WEEE.
>Do not dispose of your product or any of its acces-
sories in the household waste.
>Make sure the old unit and any accessories are dis-
posed of properly.
>Deposit the product at an appropriate collection point for the
treatment, evaluation and recycling of WEEE.
>Observe all relevant regulations.
iBy adhering to this directive, you are helping the
environment and contributing to the preservation of
natural resources and the protection of human
health.
10 Guarantee and customer service
10.1 Vaillant warranty
We only grant a Vaillant manufacturers warranty if a suitably
qualified engineer has installed the system in accordance with
Vaillant instructions. The system owner will be granted a war-
ranty in accordance with the Vaillant terms and conditions. All
requests for work during the guarantee period must be made to
Vaillant Service Solutions (0870 6060 777).
10.2 Vaillant Service
To ensure regular servicing, it is strongly recommended that
arrangements are made for a Maintenance Agreement. Please
contact Vaillant Service Solutions (0870 6060 777) for further
details.
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.)
A
2
Delay fuse
A
T 4 A/250 V
Contact voltage for DHW cylinder
thermostat
V
230
Temperature sensor (NTC) operating
voltage
V
5
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
Supplier
0020140122_03 - 12/19
Subject to engineering changes