Vaillant TURBOmax VUW 282/1 E User guide

TURBOmax VUW 242/1 E
TURBOmax VUW 282/1 E
Wall hung room sealed fan assisted
combination boilers
INSTRUCTIONS FOR INSTALLATION AND SERVICING
HEATING, CONTROLS, HOT WATER.

2
Page
1. Introduction 3
2. Boiler Specification 4
2.1 Technical Data 4
2.2 Dimensions 5
2.3 Boiler connections 5
2.4 Function diagram 6
3. General Requirements 7
3.1 Related documents 7
3.2 Boiler location 7
3.3 Gas supply 8
3.4 Flue system 8
3.5 Air supply 10
3.6 Electricity supply 10
3.7 Guide to system requirements 10
4. Boiler installation sequence 13
4.1 General 13
4.2 Boiler delivery 13
4.3 Preparation of boiler location 14
4.4 Installing the flue system 16
4.5 Mounting the boiler 16
4.6 Connecting the flue assembly
to the boiler 17
4.7 Electrical installation 19
4.8 Controls 20
5. Commissioning 22
5.1 Preliminary electrical checks 22
5.2 Gas supply 22
5.3 Water supply 22
5.4 Filling the heating system 23
5.5 Initial system flush ('cold') 23
5.6 Initial lighting 24
5.7 Gas inlet working pressure 25
5.8 Main burner pressure 25
5.9 Adjusting central heating
output (range rating) 26
5.10 Functional checks 27
5.11 Checking flame
supervision device 28
5.12 Final system flush ('hot') 28
5.13 Fitting case 28
5.14 Handing over to user 29
Page
6. Servicing 29
6.1 Initial inspection 29
6.2 Routine maintenance 30
6.3 Re-commissioning the boiler 31
7. Parts replacement 32
7.1 Initial preparation 32
7.2 Fan 34
7.3 Air pressure switch 34
7.4 Burner 35
7.5 Electrodes 35
7.6 Temperature sensor (NTC) 36
7.7 Gas valve 36
7.8 Main Heat exchanger 37
7.9 CH expansion vessel 38
7.10 Transformer 39
7.11 Overheat thermostat 39
7.12 Pump 39
7.13 Automatic air release 40
7.14 Automatic bypass 40
7.15 Diverter valve 40
7.16 Pressure and temperature
gauge 41
7.17 Differential pressure switch 41
7.18 DHW microswitch 42
7.19 DHW heat exchanger 42
7.20 Circuit boards 43
8. Fault finding 44
8.1 Introduction 44
8.2 Logical fault finding procedure 44
8.3 Fault finding charts 45
9. Electrical diagrams 54
9.1 Functional flow diagram 54
9.2 Wiring diagram 55
9.3 Schematic appliance
circuit diagram 56
10. Short parts list 57
11. Supplementary LPG
information 59
Leave these instructions with the user
when the installation is completed.

33
1. Introduction Note: This boiler must be installed
and serviced by a competent person
in accordance with the Gas Safety
(Installation and Use) Regulations
1994. In the UK 'CORGI' Registered
Installers undertake the work to a
safe and satisfactory standard.
The TURBOmax is a fully
automatic, wall mounted, room sealed
combination boiler for central heating
and domestic hot water. Domestic hot
water is supplied directly from the
boiler, without requiring a copper
cylinder, cold water tank, feed and
expansion tank or associated
pipework. Domestic hot water has
priority over central heating.
The boiler has been designed for use
with a sealed central heating system,
and comes fully tested and assembled
with a built-in circulating pump,
bypass, expansion vessel and diverter
valve.
TURBOmax boilers carry 'CE' Mark.
This demonstrates that the boilers fulfill
the essential requirements of the Gas
Appliance Directive (90/396/EEC)
and the Gas Appliance (Safety)
Regulations 1992.
The 'CE' Mark also demonstrates that
the boilers comply with the
requirements of the Electromagnetic
Compatibility Directive (Directive
89/336/EEC), the Low Voltage
Directive (73/23/EEC), the Boiler
Efficiency Directive (92/42/EEC) and
the Boiler (Efficiency) Regulations
1993.
TURBOmax meets the requirements of
Statutory Instrument ‘The Boiler (Effi-
ciency) Regulations 1993 and
therefore is deemed to meet the
requirements of Directive 92/42/EEC
on the efficiency requirements for new
hot-water boilers fired with liquid or
gaseous fuels.
The TURBOmax range consists of
models with outputs for domestic hot
water of 24 and 28 kW. The boiler is
easily sited on any internal wall and
can be installed with either a horizontal
or vertical RSF (Room Sealed Fan
assisted) flue. Flue extensions and
additional bends and elbows are
available for increased siting flexibility.
(The boiler is not suitable for external
installation).
If desired an inhibitor may be used in
the system. Guidance on the use
of inhibitors is contained in these
instructions.
Natural Gas and LPG versions of the
boiler are available.
The boiler contains a domestic hot
water heat exchanger. The temperature
in the heat exchanger is limited by the
boiler control system and it is not
necessary to install a scale reducer on
the cold mains inlet to the boiler.
However, in exceptionally hard water
areas to prevent scale formation in the
property hot water system
pipework, a scale reducer may be
fitted.
The TURBOmax has built-in diagnostic
indicator lights which illuminate in
sequence giving information on the
boiler status when operating and per-
formance of key components to aid in
commissioning and fault finding.
The data badge is fitted on the bottom
of the combustion chamber.
See text of General Requirements for
Installation Requirements or notes.

TURBOmax VUW 242/1 E VUW 282/1 E units
Countries of Destination GB, IE
Maximum CH heat input 29.3 34.2 kW
(100,000) (116,600) (Btu/h)
CH heat output range 9.6-24.0 11.2-28.0 kW
(32,800-81,900) (38,200-95,500) (Btu/h)
Maximum DHW heat input 29.3 34.2 kW
(100,000) (116,600) (Btu/h)
Maximum DHW heat output range 9.6-24.0 11.2-28.0 kW
(32,800-81,900) (38,200-95,500) (Btu/h)
DHW flow rate @ 35 °C rise 10 11.5 l/min
Mains water pressure required for max. flow rate 0.8 1.0 bar
Minimum water flow rate 2.7 2.7 l/min
Mains water pressure required for min flow rate 0.3 0.3 bar
Maximum inlet water pressure 10 10 bar
Inlet gas working pressure required (Natural Gas) 20 20 mbar
Gas supply (G20) Gross C.V. (s.t.) 37.8 37.8 MJ/m3
Gas burner pressure max. rate 10.0 10.6 mbar
Gas burner pressure ignition rate 2.0 2.0 mbar
Gas rate max (DHW) 2.79 3.26 m3/h
Main burner jet size 16 x 7/120 18 x 7/120 no. x size
CH flow temperature range 40-90 40-90 °C
Minimum CH water flow (for 20 °C rise) 1,032 1,204 l/h
Pump pressure available 0.25 0.25 bar
8l expansion vessel pre-charge pressure 0.75 0.75 bar
Maximum CH system pressure 3.0 3.0 bar
Connections
Heating flow / return 22 22 mm
Cold water inlet 15 15 mm
DHW outlet 15 15 mm
Gas inlet 15 15 mm
Pressure relief discharge pipework (min) 15 15 mm
Weight 47 48 kg
Primary water content 0.7 0.7 litres
Electrical supply
Voltage 230/50 230/50 V~/Hz
2 x internal fuses 2 2 A
1 x internal fuse 1.25 1.25 A
external fuse 3 3 A
Power input 130 130 W
4
2. Boiler specification
2.1 Technical data
Supplementary LPG information on page 59.

55
1021
880
95.5
480
120 max. 995* max. 995 *
1a
1a
190
1b
2
765438
35
50 380
120
GW 547/1
fig. 1
2.3 Boiler connections
1 Compression union (flow of
heating system)
2 Service valve (flow of heating
system)
3 Domestic hot water connection
4 Compression Union (gas)
5 Gas service valve (supplied with
the boiler)
6 Cold water connection with
shut-off valve
7 Service valve (return of heating
system)
8 Compression union (return of
heating system)
9 Pressure relief valve
200
124
50
35
70
25
12 3456789
GW 546/1
fig. 2
2.2 Dimensions
(All dimensions in mm)
1a Air/flue duct to the rear
1b Air/flue duct to the side
2 Appliance bracket
3 Heating system return (22 mm)
4 Cold water connection (15 mm)
5 Gas connection (15 mm)
6 Hot water connection (15 mm)
7 Heating system flow (22 mm)
8 Pressure relief valve outlet
(3/4in BSP)
* with standard horizontal flue
accessory.
(max. = 2965 mm with extensions)

66
1
9
2
3
4
5
6
78
1
9
2
3
4
5
6
78
υ
0
0
60
90
120
4
321
30
1
2
3
4
5
7
6
8
9
10
11
12
13
14
15
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
GW 573/2GB
fig. 3
2.4 Function diagram
1 Air duct
2 Air pressure switch
3 Combustion chamber
4 Temperature sensor (NTC)
5 Ignition electrodes
6 Modulating burner
7 Overheat thermostat
8 Fully modulating automatic gas
valve
9 DHW heat exchanger
10 Indicator lights (LED’s)
11 Maximum radiator temperature
control
12 Maximum hot water temperature
control
13 Central heating control and
lockout reset
14 Main on/off control
15 CH flow service valve
16 Gas service valve
17 Flue gas duct
18 Fan
19 High efficiency heat exchanger
20 Flame sensing electrode
21 Differential pressure switch
22 Expansion vessel charging valve
23 Expansion vessel
24 Automatic air vent
25 Circulating pump
26 Diverter valve
27 Water switch (DHW)
28 Water section
29 Temperature and Pressure gauge
30 Automatic bypass valve
31 Pressure relief valve
32 CH return service valve
33 Cold water shut off valve

7
3. General requirements 3.1 Related documents
The installation of the boiler must be
in accordance with the relevant
requirements of Gas Safety (Installation
and Use) Regulations 1994, Health
and Safety Document No. 635 (The
Electricity at Work Regulations 1989),
BS7671 (IEE Wiring Regulations) and
the byelaws of the local Water
Undertaking. It should also be in
accordance with the relevant
requirements of the Local Authority,
Building Regulations, Building
Standards (Scotland) Regulations and
the relevant recommendations of the
following British Standards:-
BS 5440: Flues and ventilation of gas
fired boilers not exceeding 60 kW:
- Part 1: Flues
- Part 2: Ventilation
BS 5449: Specification for forced
circulation hot water for domestic
premises.
BS 5546: Specification for gas hot
water supplies for domestic premises.
BS 6700: Services supplying water
for domestic use within buildings and
their curtilages.
BS 6798: Specification for installation
of gas fired boilers not exceeding 60
kW input.
BS 6891: Specification for installation
of low pressure gas pipework up to
28 mm (R1) in domestic premises (2nd
family gas).
BS 7593: Treatment of water in
domestic hot water central heating
systems.
BRITISH GAS PUBLICATION DM2:
Guide for Installation in Timber
Framed Housing
Important
The appliance must be installed and
serviced by a competent person as
stated in the Gas Safety (Installation
and Use) Regulations 1994
3.2 Boiler location
The location chosen for the boiler must
permit the provision of a satisfactory
flue termination. The location must
also provide adequate space for
servicing and air circulation around
the boiler. The boiler may be installed
in any room, although particular
attention is drawn to the requirements
of BS7671 (I.E.E. Regulations) and, in
Scotland, the electrical provisions of
the Building Standards (Scotland)
Regulations,in respect of the installation
of a boiler in a room containing a
bath or shower.
(Note: Where a room sealed boiler
is installed in a room containing a
bath or shower, any electrical switch
or boiler control utilising mains
electricity should be so situated that it
cannot be touched by a person using
the bath or shower).
Where the installation of the boiler
will be in an unusual location, special
procedures may be necessary and BS
5546 and BS 6798 give detailed
guidance on this aspect.
The boiler must be mounted on a flat,
vertical wall, which must be sufficiently
robust to take the weight of the boiler.
The boiler may be installed on a
combustible wall, subject to the
requirements of the Local Authorities
and Building Regulations.
A compartment used to enclose the
boiler must be designed and
constructed specifically for this
purpose. (An existing cupboard or
compartment may be used provided
that it is modified for the purpose).
Details of essential features of
cupboard/compartment design
including airing cupboard installations
are given in BS 6798.
If the boiler is to be fitted in a timber
framed building, it should be fitted in
accordancewith British Gas Publication
DM2 'Guide for Gas Installations in
Timber Framed Housing'.

8
3.3 Gas supply
The gas supplier should ensure the
availability of an adequate supply of
gas.
A gas meter may only be connected
to the service pipe by the supplier of
gas or their contractor.
An existing meter should be checked
to ensure that it is capable of passing
the rate of gas supply required.
Installation pipes should be fitted in
accordance with BS 6891.
Pipework from the meter to the boiler
must be of an adequate size. Do not
use pipes of a smaller size than the
boiler gas connection (15 mm).
The complete installation must be
tested for soundness and purged as
described in BS 6891.
3.4 Flue system
The standard horizontal flue system
(Art. No. 300 807) is suitable for
installations up to 995 mm measured
from the centre of the boiler flue outlet
to the outside face of the wall (A, fig.
4). Flue extensions (Art. No. 300 802)
are available to extend this length up
to 2965 mm. Both 90°elbows
(Art. No. 300 808) and 45°bends
(Art. No. 300 809) are also available
to increase siting flexibility.
A vertical flue system is also available
(Art. No. 300 800).
TURBOmax boilers may also be used
in SE- duct applications (SE- duct flue
system available Art. No. 300810)
Refer to the flue installation instructions
for full details.
A max = 2965 mm
GW 579/2
fig. 4

3.4.1 Flue Termination
1. The terminal must be positioned
such that the combustion products can
disperse freely at all times.
2. In certain weather conditions a
plume of water vapour may be visible
from the flue terminal. Positions where
this could be a nuisance should be
avoided.
3. If the terminal is fitted less than 2m
above a balcony, above ground or
above a flat roof to which people
have access, then a suitable guard
must be provided and fitted (available
from Tower Flue Components,
Tonbridge, TN9 1TB: reference TFC
type K3).
Table 1:
Terminal position for fan-assisted flue
(minimum distance - see fig. 5)
A- Directly below an openable mm
window or other opening
(e.g. air brick) 300
B- Below gutters, soil pipes
or drain pipes 25
C- Below eaves 25
D- Below balconies 25
(below car port roof 200)
E- From vertical drain pipes
and soil pipes 25
F- From internal or external
corners 25
G-Above ground or balcony
level 300
H- From a surface facing a
terminal 600
I- From a terminal facing a
terminal 1200
J- From an opening in a
car port (e.g. door, window)
into a dwelling 1200
K- Vertically from a terminal
on the same wall 1500
L- Horizontally from a
terminal on the same wall 300
M-Distance from adjacent
wall for Vertical Flue 500
9
A
BCD
A
G
H, I
FJ
BFM
L
L
KK
G
G
FF
E
fig. 5
GW 595/1
Where a terminal is fitted less than
1m below a plastic gutter or less than
0.5 m below painted eaves or any
other painted surface then a suitable
shield at least 1m long should be
fitted to protect the surface.
Note: Vertical flues must not terminate
within 600 mm of an openable
window, air vent or any other
ventilation opening.

10
3.5 Air supply
Detailed recommendations for air
supply are given in BS 5440: Part 2.
It is not necessary to have an air vent
in the room or internal space in which
the boiler is installed.
3.5.1 Cupboard or compartment air
supply
TURBOmax Room Sealed Combination
Boilers are very high efficiency
appliances.
As a consequence the heat loss from
the appliance casing during operation
is very low. For cupboard and
compartment installations it is therefore
not necessary to provide any high or
low level permanent air vents for
cooling purposes.
3.6 Electricity supply
A 230 V~ 50Hz single phase
electricity supply fused to 3 amps must
be provided in accordance with the
latest edition of BS7671 (I.E.E. Wiring
Regulations) and any other local
regulations that may apply.
THIS APPLIANCE MUST BE EARTHED.
The method of connection to the mains
electricity supply must provide a
means of completely isolating the
boiler and its ancillary controls.
Isolation is preferably by the use of a
fused three pin plug and unswitched
shuttered socket outlet, both complying
with the requirements of BS 1363.
Alternatively, a 3 Amp fused
double-pole switch with a 3mm
contact separation on both poles may
be used.
3.7 Guide to system
requirements
3.7.1 Water circulation system
Detailed recommendations for the
water circulation system are given in
BS 6798 and BS 5449: Part 1 (for
small bore and micro bore central
heating systems).
Pipework not forming part of the useful
heating surface should be insulated to
help prevent heat loss and possible
freezing, particularly where pipes are
run through roof spaces and ventilated
underfloor spaces.
Draining taps must be located in
accessible positions which permit the
draining of the whole system including
the boiler and the hot water system.
Draining taps should be at least 1/2
in. BSP nominal size and be in
accordance with BS 2879.
The boiler is suitable for use with
minibore or microbore systems.
Copper tubing to BS 2871: Part 1
should be used for water carrying
pipework. All capillary joints in the
DHW pipework must be made with
lead free solder.
Particularly where a new boiler is to
be fitted to an existing system, it is
good practice that the system is
thoroughly cleansed. This cleasing
should take place prior to the fitting of
the new boiler and be in accordance
with BS 7593.
For advice on the application of
system cleansers contact Sentinel,
Grace Dearborn Ltd, Widnes,
Cheshire, WA8 8UD.
Tel: [phone].

11
Heating
circuit
return Double check
valve assembly Hose
unions
Temporary
Hose
Test
valve
Stop
valve
Mains
water
supply
fig. 6
GW 400/1
3.7.2 Filling and make up
The system should be filled with water
via a separate filling point fitted at a
convenient position on the heating
circuit. Where local Water Authority
Regulation allows, a temporary
connection to the mains may be used
(fig. 6). The connection must be
removed when filling is completed.
Where local Water Authority
Regulation does not allow temporary
connection, a sealed system filler
pump with break tank must be used.
The heating system will not be filled
automatically from the domestic hot
water side.
(Alternative methods of filling sealed
systems are given in BS 5449).
3.7.3 Pressure relief valve
A pressure relief valve is provided
ready assembled within the boiler
(5, fig. 7). This safety device is
required on all sealed C.H. systems
and is pre-set at 3 bar and provided
with a 3/4 in. BSP connection for a
discharge pipe, which must be of no
less than 15 mm diameter.
3.7.4 Pressure and temperature gauge
This is factory fitted to the boiler and
indicates the primary circuit pressure
to facilitate filling and testing, as well
as showing the temperature of the
central heating system water.
11
8
1
4
10
7
9
5
6
2
3
fig. 7
GW 609/1

12
Safety valve setting (bar) 3.0
Initial system pressure (bar) 1.0 1.5
Total water content of system VESSEL VOLUME (L)
litres
25 2.7 3.9
50 5.4 7.8
100 10.9 15.6
125 13.6 19.5
150 16.3 23.4
175 19.1 27.3
200 21.8 31.2
225 24.5 35.1
250 27.2 39.0
275 30.0 42.9
300 32.7 46.8
325 35.7 50.7
350 38.1 54.6
375 40.9 58.5
400 43.6 62.4
425 46.3 66.3
450 49.0 70.2
475 51.8 74.1
500 54.5 78.0
For system volumes other than
those given above, multiply 0.109 0.156
the system volume by the factor
across
13,3 400
ft mbar
10 300
6,7 200
3,3 100
00 200 400 600 800 1000 1200 1400 1600 l/h
Q
fig. 8
GW 402/2
3.7.5 Expansion vessel
An expansion vessel is incorporated
into the boiler suitable for a sealed
heating system with a maximum water
content of 100 litres.
If the nominal capacity of the built in
expansion vessel is not sufficient for
the heating system (for instance in
case of modernisation of old open
systems) an additional expansion
vessel can be installed external to the
boiler. It should be fitted in the return
pipe as close as possible to the boiler
in accordance with BS 5449: Part 1.
Guidance on the sizing of an
additional expansion vessel is given in
Table 2.
3.7.6 Circulating pump
The circulating pump is included in the
boiler. The pump head available for
the heating system is shown in fig. 8.
3.7.7 System by-pass
An automatic system by-pass is
included within the boiler. The boiler
is suitable for use in systems with
thermostatic radiator valves and no
additional by-pass is required.
3.7.8 Venting
The boiler is fitted with an automatic
air vent. Additional provision should
be made to enable the heating system
to be vented during filling and
commissioning either by automatic air
vents or manually.
3.7.9 DHW expansion vessel
accessory
A DHW expansion vessel kit (Art. No.
8070) is available as an optional
accessory from Vaillant Ltd. This
expansion vessel kit should be fitted
to the boiler whenever either a stop
valve of the loose jumper type or a
non return valve are present in the
cold water mains supply to the boiler
(fig. 9).
Table 2: Sizing of Additional Expansion Vessel
D.H.W. expansion
vessel fitted to the boiler
Non return
valve
Stop valve
Mains water
supply
fig. 9
GW 494/1

4. Boiler installation
sequence
4.1 General
The boiler should be mounted on a
flat and vertical area of wall of
sufficient area for the boiler plus the
required minimum clearances for
installation and servicing (fig. 10).
These are shown on the installation
template supplied with the boiler and
are:
5 mm either side of the boiler
100 mm below the boiler*
165 mm on top of the boiler
500 mm in front of the boiler **
* 150 mm where optional pre-
installation connecting group
(Art. no. 8015) is used.
** This clearance is only required to
enable easier access to the boiler
for servicing and may be
provided by an openable door,
etc.
Note: If the boiler is to be fitted in a
timber framed building, it should be
fitted in accordance with British Gas
publication reference DM2 'Guide
for gas installations in timber framed
housing.'
4.2 Boiler delivery
The TURBOmax is delivered in two
packs:
a. the carton containing the boiler
b. separately boxed flue accessory,
either:
•1m horizontal flue accessory
(Art. No. 300 807); or
•vertical flue accessory
(Art. No. 300 800)
13
5mm 5mm
165mm
*100mm
fig. 10
GW 403/2

Standard Accessories Art. No.
1. Air/flue duct and terminal accessory 300 807
Optional Accessories Art. No.
1. Vertical air / flue duct (including terminal) 300 800
2. Pitched roof adjustable roof tile
(for use with vertical air/flue duct) 9076
3. Flat roof penetration collar
(for use with vertical air/flue duct) 9056
4. 1 m air /flue duct extension 300 802
5. 2 m air / flue duct exension 300 803
6. Additional 90°elbow for air / flue duct 300 808
7. Additional 45°bends (pair) for air / flue duct 300 809
8. Additional air / flue duct joint clamps (pair) 300 806
9. Se- duct flue kit 300 810
10. Internal flue fixing kit 8098
11. Pre - installation connecting group
(includes 300 813) 8015
12. Vaillant boiler replacement connection accessory 300 813
13. Pipe cover accessory 8099
14. Plug in 24 hour central heating timeclock 300 820
15. Plug in 7 day central heating timeclock 300 821
14
4.2.1 Installation accessories
Table 3 lists the standard and optional
accessories which are available for
the TURBOmax combination boilers.
4.2.2 Unpack the boiler (fig. 11)
Open the boiler carton and remove:
a. protective cardboard sheet
b. top and bottom decorative panels
c. polystyrene packaging
Note: Care should be taken not to
scratch the white surface of the boiler
casing.
Packed in the boiler carton are the
following:
•boiler installation template
•boiler hanging bracket
•gas service valve
•fixing screws and wallplugs
•installation and user instructions
•flue restrictor
•domestic hot and cold water
connections and straddle bracket
4.3 Preparation of boiler
location
4.3.1 Select position of boiler.
Refer to Section 3.2 'Boiler Location'
for information regarding siting the
boiler. In general the boiler must be
positioned such that:
•there is adequate space around the
boiler for service and maintenance
•the boiler can be correctly flued,
i.e. the flue terminal position is sited
in accordance with Section 3.4.1
and the air / flue duct can be
installed in accordance with the
flue installation instructions
supplied.
•all necessary pipework can be
connected, including the pressure
relief valve discharge pipe.
fig. 11
GW 601/1
Table 3: Installation Accessories

15
4.3.2 Using the boiler template
(fig. 12)
4.3.2.1 Once a suitable location has
been chosen, fix the paper installation
template on the wall ensuring that the
centerline of the template is vertical
using a spirit level or plumb line.
The template shows the positions of
the fixing holes for the boiler hanging
bracket (2) and the optional
pre-installation connection group (3).
The template also shows the position
of the flue exit hole, for use where the
air flue duct is to be installed directly
to the rear of the boiler, e.g. where
the boiler is installed on an outside
wall and the flue terminates directly
behind.
4.3.2.2 A Pre - installation connection
group (Art. No. 8015) is available as
an optional accessory. It is used to
allow the installation of the central
heating and domestic hot water
pipework without the need to have the
boiler in position. Where an old
existing Vaillant boiler is to be
replaced, the boiler replacement
accessory (Art. No. 300 813) can be
used to allow easy connection on the
new boiler to the existing connecting
group. Refer to the instructions
supplied separately with these
accessories.
4.3.2.3 Mark on the wall the positions
of the hanging bracket fixing holes (2).
Drill two holes Ø10 mm for the
hanging bracket. (Note: Use the
alternative fixing holes where
necessary).
4.3.2.4 Rear exit flue.
Mark the position of the centre of the
flue duct and its circumference, e.g.
by drilling through the template
(1, fig. 12).
4.3.2.5 Other flue options.
Refer to the installation instructions
supplied with the flue accessory for
detailed instructions on other flue
options such as vertical RSF flues, flue
runs to the side of the boiler and the
use of additional flue elbows and
bends etc.
4.3.2.6 Remove the template from the
wall and plug the drilled holes using
the wallplugs supplied.
1
2
3
fig. 12
GW 426/1
4.3.3 Fitting the boiler hanging
bracket.
Secure the hanging bracket to the
wall using the screws supplied. (If the
condition of the wall is poor it may
be necessary to use additional or
alternative fixings to ensure adequate
support).
NOTE: If the boiler is to be fitted in a
timber framed building ensure that the
brackets are secured to a substantial
part of the timber frame capable of
taking the weight of the boiler.

4.4 Installing the flue system
At this stage install the flue system
(refer to separate installation
instructions supplied).
4.5 Mounting the boiler
4.5.1 Preparation
Remove the boiler from the carton.
Lay the boiler on the floor and
remove the white boiler bottom cover
by removing two screws (1, fig. 51)
and slackening two screws (2, fig.
51). Do not remove boiler side
panels. Remove the two plastic sea-
ling caps from the domestic water
connections.
Fit the pre-assembled cold water inlet
and hot water outlet pipes with
straddle bracket (1,2,3, fig. 15) to
water connections on boiler (4, fig.
15) using washers provided.
4.5.2 Fitting the boiler (fig. 13)
Lift the boiler up to the wall so that it is
slightly above the hanging bracket.
Note: Lift the boiler from under the
front edge of the side panels.
Do not lift the boiler by the control
box. Do not attempt to lift the boiler
without the side panels or side
casing fitted.
Lower the boiler slowly onto the
hanging bracket so that the cross
member at the top rear of the boiler
fully engages into the hanging
bracket.
4.5.3 Pipework connections (fig. 14)
Figure 14 shows the central heating,
domestic hot water, mains cold water,
gas and pressure relief valve
connections.
4.5.3.1 Central heating flow and
return
Before connecting the heating circuit
to the appliance, all pipework and
radiators must be thoroughly flushed
to remove any installation debris.
Connect the flow and return pipes to
the central heating service valves (8)
and (9) on the appliance using the
22 mm compression connections.
4.5.3.1.1 Top pipework connection
If it is desired to run heating and
water pipework to above the boiler,
the purpose provided voids in the left
and right sides of the boiler casing
may be used (see fig. 16).
Note: To allow fitting of the bottom
boiler cover, the left hand tab (2, fig.
16) should be folded upwards where
pipes are fitted in the left hand void.
Where pipes are installed in these
voids, a method of disconnection e.g.
a compression connector (1, fig. 16)
must be provided to allow easy
removal of the boiler from the wall, if
required.
4.5.3.2 Cold mains water inlet and
hot water outlet (fig. 14)
Flush out all foreign matter from the
mains supply pipe before connecting
to the boiler.
Connect the mains water supply (3)
and hot water outlet pipes (4) to the
15 mm compression connections.
Note: The boiler has a maximum
domestic water working pressure of
10 bar. If the cold mains supply
pressure exceeds 10 bar, a pressure
reducing valve must be fitted to the
cold water inlet.
4.5.3.3 Pressure relief valve discharge
The appliance contains the pressure
relief valve required for a sealed
system (5). Connect a discharge pipe
not less than 15 mm diameter to the
outlet of this valve.
This discharge pipework should be as
short as possible and installed with a
continuous fall away from the boiler.
The pipe should terminate in a position
which ensures that any discharge of
water or steam from the valve cannot
create a hazard to persons in or
about the premises, or cause damage
to any electrical components or
external wiring, and the point of
discharge should be clearly visible.
The discharge must not terminate
above a window, an entrance or any
type of public access. The installer
must consider that the pipe could
discharge boiling water.
16
fig. 13
GW 608/1GB
11
8
1
4
10
7
9
5
6
2
3
fig. 14
GW 609/1
1
3
2
4
fig. 15
GW 706/1
2
1
fig. 16
GW 1001/1

4.5.3.4 Gas supply
The boiler is supplied with a 20 x 15
mm gas service valve (10, fig. 14). Fit
the 20 mm compression fitting to the
boiler gas inlet (11, fig. 14) and
tighten. Install a gas supply pipe not
less than 15 mm diameter and connect
to the gas service valve. (Ensure the
gas supply pipework is adequately
sized such that a 20 mbar - (8" w.g.) -
gas pressure is available at the boiler
inlet at full flow rate). Tighten all union
connections.
4.6 Connecting the flue
assembly to the boiler
Note : A flue restrictor ring is sup-
plied packed with the users and
installation instructions.
The restrictor should be used under
the following circumstances : -
Horizontal flues
Where a horizontal flue less than 1 m
in length is used.
(DO NOT fit the restrictor where the
horizontal flue is more than 1 m in
length).
Vertical flues
Where a vertical flue less than 1 m
(e.g. 1 m between the top of the
boiler and the bottom of the vertical
air / flue duct assemly) is used
(DO NOT fit the restrictor where the
vertical flue is more than 1 m in
length).
4.6.1 Horizontal Flue
Remove two screws (1, fig. 18) and
take off one half ring (2, fig. 18). If
necessary, fit the flue restrictor ring
(Note : It will be necessary to remove
both half rings if the flue restrictor ring
is to be fitted. The flue restrictor ring
should be placed on top of flue outlet
directly below the two half rings see
fig. 18a. One half ring should be
replaced immediately).
Place a 63 mm diameter x 35 mm
wide flue duct clamp (4, fig. 19)
loosely over the flue duct (1, fig. 19).
Place the 63 mm diameter x 25 mm
wide flue duct clamp (5, fig. 19) over
the flue gas connection on the boiler.
17
3
2
1
fig. 18a
GW 705/1
12
fig. 18
GW 592/1
54123
fig. 19
GW 593/1
34
5
6
1
2
fig. 17
GW 823/1

Loosen screws on the 95 mm diameter
x 55 mm wide clamp (6, fig. 21) and
push over the air duct.
Remove screws and sealing washer
on the 95 mm diameter x 25 mm
wide clamp (3, fig. 21) and push onto
the flue elbow on the side to be
connected to the appliance. Ensure
the clamp is clear of the end of the
elbow.
Push the flue elbow into the clamp (2,
fig. 20) connected to the appliance
flue gas duct and tighten the securing
screws lightly.
Ensure that the elbow and air/flue
duct line up and are closely butted
together. Pull the clamp (4, fig. 20)
over the joint between the flue gas
duct and flue elbow. Ensure that the
air/flue duct and terminal are correctly
positioned. Tighten the securing screws
on both clamps.
Note : Excessive tightening of these
screws is not necessary. Ensure that
the air / flue duct and terminal
assembly is not displaced though the
wall. Check that the air duct of the
terminal still projects by 90 mm
through the wall.
Refit the half ring 2, fig. 21. Pull the
95 mm diameter x 25 mm wide
clamp (3, fig. 21) over the joint
between the flue elbow and half rings.
Refit the screws and sealing washer
and tighten lightly.
Pull the 95 mm diameter x 55 mm
wide clamp (6, fig. 21) over the joint
between the flue elbow and air/flue
duct. Tighten the securing screws on
both clamps.
Drill two holes, 3 mm diameter
through both air duct clamps into the
air ducts at the most convenient
positions (5, fig. 21). Take care not to
penetrate the inner flue duct. Screw
the clamps to the air ducts using the
self tapping screws provided.
4.6.2 Vertical Flue
Remove the two half rings (2, fig. 18)
and, if necessary, fit the flue restrictor
ring.
(Note: It will be necessary to remove
both half rings if the flue restrictor ring
is to be fitted. The flue restrictor ring
should be placed on top of flue outlet
directly below the two half rings (see
fig. 18A). One half ring should be
replaced immediately).
Fit the 63 mm diameter x 68 mm wide
flue duct sleeve (2, fig. 22) over the
flue gas duct of the air/flue duct
assembly.
Loosen the screws of the 95 mm
diameter x 55 mm wide clamp (1, fig.
22) and push over the air duct of the
air/flue duct assembly.
Lower the flue assembly until a gap of
about 25 mm exists between the air
duct of the air/flue duct and terminal
assembly and the half rings on the
appliance. The two ducts must not butt
together.
Pull the sleeve (2, fig. 22) down over
the flue connection of the appliance
against the stop. Align the holes in the
sleeve and boiler flue gas connector
and secure with a self tapping screw
(1, fig.23).
Note : The sleeve must not be screwed
to the bottom of the flue gas duct of
the air/flue duct assembly. This duct
must be able to slide in order to
absorb small movements of the roof
structure.
Refit the two half rings. Pull the 95 mm
diameter x 55 mm wide clamp down
over the joint between the air/flue
duct assembly and the half rings. Tigh-
ten the clamp screws (1, fig.24).
18
1234567
fig. 21
2341
fig. 20
GW 616/1
GW 594/1
3
1
2
fig. 22
GW 558/1
1
232
fig. 24
GW 602/1
12
fig. 23
GW 560/1

Drill two holes 3 mm diameter
through the air duct clamp (2. Fig 24)
ensuring that the drill does not pene-
trate the flue duct. Screw the clamp to
the boiler half ring using the self tap-
ping screws provided.
Note: The air duct clamp must not be
screwed to the bottom of the air flue
duct and terminal assembly. The
air/flue duct and terminal assembly
must be able to slide in the air duct
clamp to absorb any slight
movements in the roof structure.
4.7 Electrical installation
4.7.1 General electrical requirements
All electrical work shall be carried out
by a competent person and shall
comply with BS7671 (IEE
Regulations).
The boiler is supplied for connection
to a 230V~ 50Hz supply fused at 3A
rating. Connection to the mains supply
should be made via a fused 3 pin
plug to an unswitched, shuttered
socket, both complying with the
requirements of BS1363.(Alternatively,
connection may be made via a 3
Amp fused double pole isolator
having a contact separation of at least
3mm in all poles and supplying the
boiler and controls only).
The point of connection to the mains
must allow complete electrical isolation
of the boiler and its ancillary controls.
It should be readily accessible and
adjacent to the boiler. A 3 core
flexible cord according to BS6500
tables 6, 8 or 16 (3x0.75 to 3x1.5
mm2) should be used.
Warning: This appliance must be
earthed
4.7.2 Connecting to mains supply
Slacken front panel fixing screw (1,
fig. 25) and lower front panel. Remove
terminal box cover by undoing screw
(1, fig. 26)
Connect the power supply cord as
follows (see fig. 27):-
green / yellow (earth) wire....
boiler terminal
Blue (neutral) wire..... boiler terminal N
Brown (live) wire..... boiler terminal L
Note: Do not use boiler terminal
connections 7-8-9
19
12
fig. 25
GW 603/1
13
2
fig. 26
GW 614/1
N
L
3
4
5
7
8
9
1
2
fig. 27
GW 1528/0GB
1
fig. 28
GW 1527/0
IMPORTANT Ensure that all cords
pass through the terminal box entrance
grommets and are securely fixed by
the cable clamps. Ensure that the
power supply cord is connected such
that the current carrying conductors
become taut before the earthing
conductor should the supply cord slip
from the cable clamp.
Refit the terminal box cover after
completion of all electrical components.
The cable clamp (1, fig. 28) is only
meant as a mounting aid. A possible
damage caused when mounting or
removing it will not cause any
malfunction of the appliance.

NL 43
NL 43
345
20
43NL
NL 4
4.8 Controls
4.8.1 External electrical controls
The boiler terminals 3,4 and 5 are for
connecting external controls such as a
time switch and/or room thermostat.
Terminals 3 and 4 are linked together
when the boiler is supplied. If external
controls are used, this link must be
removed, and the controls connected
across terminals 3 and 4.
Terminal 5 is an additional neutral
connection for external neutrals such
as from the anticipator of a room
thermostat.
Refer to Section 4.8.2 for full
connection details.
4.8.2 Connection of external electrical
controls
4.8.2.1 Connection details for
programmable thermostat and boiler
terminal strip (refer to fig. 29).
Fig. 29 shows the connection details
where a programmable thermostat
(time switch with built-in room
thermostat) is used to control the
boiler. (Important: The arrowed
numbers indicate connection into the
relevant terminal in the boiler terminal
strip).
4.8.2.2 Connection details for
external time switches and boiler
terminal strip (refer to fig 29a).
Fig. 29a shows the connection details
where a time switch is used without a
room thermostat to control the boiler.
(Important: The arrowed numbers
indicate connection into the relevant
terminal in the boiler terminal strip).
If a room thermostat is to be connected
in addition to a time switch the wire
between the time switch 'ON' terminal
and boiler terminal 4 should be broken
by the contacts of the room thermostat
(see Schematic layout, fig. 30).
If a frost thermostat is to be fitted it
should be connected in parallel across
terminals 3 and 4.
4.8.2.3 Vaillant optional Plug-in timer
Accessories
Refer to the instructions supplied with
the optional plug in timer accessories
for connection details.
→
→
→
→
ACL Drayton
Lifestyle
LP711
ACL Drayton
Switchmaster 300
(Please note: Remove Link N-2 and L-4)
Grässlin Towerchron
Dt71, T200l
Honeywell
ST6100
Honeywell
ST7000B
(Battery operated)
Horstmann
425 Coronet
Channel Plus, H17, H11
Landis & Gyr
RWB100, 152, 170
Potterton Myson
EP400l, EP500l
Danfoss Randall
103, 103E, 103E7
Danfoss Randall
Set 1E, TS975
fig. 29a
7543
MAINS
SUPPLY
230 V
50 Hz
L
L
L
N
N
NN
20 V
DO NOT USE!
3 A FUSE SWITCH
CONTACTS
ROOM
THERMOSTAT
CLOCK
89
fig. 30
GW 409/1
Boiler Terminal Strip
ENL 123456
ON OFF
→
→
→
→
ENL 123456
ON OFF
→ →
→
→
→
NL12345E
OFF ON
NL 3 4
→
→
→
→
→
→
→
→
→→
NL1234
123E56
ON
NL3 4
→
→
→
→
NL1234
OFF ON
NL4 3
→
→
→
→
NL1234
ON
NL 34
→
→
→
→
NL1234
ON
NL3 4
→
→
→
→
NL1234
34
→
→
L234
OFF ON
Vaillant Calotrol
(VRT 9083 and VRT 9084)
ACL Drayton
Digistat 2 and 3
ACL Drayton
PT110, PT170
ACL Drayton
Lifestyle
CT171, CT172,
PT271, PT371
Danfoss Randall
TP2, TP3, TP4, TP5
Honeywell
CM51, CM41
Landis & Gyr
REV 10 and 21
Potterton Myson
Pot 1
fig. 29
NL 43
→
→
→
→
NL1234
NL3
→
→
→
NL1234
OFF ON
→
→
→
→
2L1NC
OFF ON
NL34
→
→
→
→
1234
34
→
→
123
34
→
→
123
34
→
→
ABC
34
→
→
Q1 Q2
Connection detail for room thermostat and time switch
Connection details for time switch
Connection details for programmable thermostats