Vaillant TURBOmax Pro 28 User guide

INSTRUCTIONS FOR
INSTALLATION AND SERVICING
TURBOmax Pro 28/2 E
Wall hung room sealed fan assisted combination boilers
The code of practice for the installation,
commissioning & servicing of central heating systems
I
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2
TABLE OF CONTENTS
Introduction
Boiler Specification
General Requirements
Boiler Installation Sequence
General information . . . . . . . . . . . . . . . . . . . . . . . . . .5
EC designation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
List of Contents Contents included with boiler . . . . . . . . . . . . . . . . . . . .4
Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Boiler connections . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Functional diagram . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Related documents . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Boiler location . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Gas supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Flue system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Rear outlet flue system . . . . . . . . . . . . . . . . . . . .11
Top outlet flue system . . . . . . . . . . . . . . . . . . . .11
Extended top outlet flue system . . . . . . . . . . . . . .11
Flue termination . . . . . . . . . . . . . . . . . . . . . . . .12
Air supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Cupboard or compartment ventilation . . . . . . . . . . . . . .13
Electrical supply . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Guide to system requirements . . . . . . . . . . . . . . . . . . .14
Water circulation system . . . . . . . . . . . . . . . . . .14
Filling and make up . . . . . . . . . . . . . . . . . . . . .14
Pressure relief valve . . . . . . . . . . . . . . . . . . . . .14
Pressure gauge . . . . . . . . . . . . . . . . . . . . . . . .14
Expansion vessel . . . . . . . . . . . . . . . . . . . . . . .15
Circulating pump . . . . . . . . . . . . . . . . . . . . . . .16
System by-pass . . . . . . . . . . . . . . . . . . . . . . . . .16
Venting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
DHW expansion vessel accessory . . . . . . . . . . . .16
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Preparation of boiler location . . . . . . . . . . . . . . .17
Selecting position of boiler . . . . . . . . . . . . . . . . .17
Using boiler template . . . . . . . . . . . . . . . . . . . . . . . . .18
Fitting the boiler hanging bracket . . . . . . . . . . . . . . . . .19
Install the flue system . . . . . . . . . . . . . . . . . . . . . . . . .19
Fitting the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Removing boiler casing . . . . . . . . . . . . . . . . . . . . . . .20
Gas supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Cold water mains inlet and hot water outlet . . . . . . . . . .22
Central heating flow and return pipework . . . . . . . . . . .23
Connecting the flue system to the boiler . . . . . . . . . . . .24
Electrical installation general requirements . . . . . . . . . . .25
Connecting to the main supply . . . . . . . . . . . . . . . . . .26
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Fit boiler casing . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Commissioning Part I Preliminary electrical checks . . . . . . . . . . . . . . . . . . . .31
Gas supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Water supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Filling the heating system . . . . . . . . . . . . . . . . . . . . . .33
Draining the heating system . . . . . . . . . . . . . . . . . . . .33
Initial system flush (`cold`) . . . . . . . . . . . . . . . . . . . . . .33

3
TABLE OF CONTENTS
Gas supply adjustments
(Commissioning Part II)
Servicing
Fault Finding Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Logical fault finding procedure . . . . . . . . . . . . . . . . . .57
Fault finding charts . . . . . . . . . . . . . . . . . . . . . . . . . .58
Diagrams Functional flow diagram . . . . . . . . . . . . . . . . . . . . . . .66
Wiring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Short parts list Short parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Initial inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Cleaning the burner and primary heat exchanger . . . . . .44
Parts replacement Safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Initial preparation . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Gas valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Temperature sensors (NTCs) . . . . . . . . . . . . . . . . . . . .49
Main heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . .49
Expansion vessel . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Electronic control board . . . . . . . . . . . . . . . . . . . . . . .51
Main transformer . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Air pressure switch . . . . . . . . . . . . . . . . . . . . . . . . . .52
System bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Diverter valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Pressure gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Aqua sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
DHW heat exchanger . . . . . . . . . . . . . . . . . . . . . . . .55
Pressure relief valve . . . . . . . . . . . . . . . . . . . . . . . . . .55
Checking functions . . . . . . . . . . . . . . . . . . . . . . . . . .56
Functional checks
(Commissioning Part III)
Functional checks . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Adjusting pump speed . . . . . . . . . . . . . . . . . . . . . . . .41
Final system flush (hot) . . . . . . . . . . . . . . . . . . . .41
Handing over to the user . . . . . . . . . . . . . . . . . . . . . .42
Gas inlet working pressure . . . . . . . . . . . . . . . . . . . . .34
Main burner pressure . . . . . . . . . . . . . . . . . . . . . . . . .35
Adjusting the central heating output (range rating) . . . . .36
Burner pressure and gas rate . . . . . . . . . . . . . . . . . . .37

4
LIST OF CONTENTS
Contents included with
boiler
Ensure that all contents are included
before commencing installation.
DO NOT remove the boiler from the
polystrene base at this stage.
BEDIENUNGSANLEITUNG
BEDIENUNGSANLEITUNG
BEDIENUNGSANLEITUNG
BEDIENUNGSANLEITUNG
8
9
9
9
BEDIENUNGSANLEITUNG
Instructions for Use
7
10
6
1
2
5
4
I
0
3
Fig. L.1: Items supplied with unit
Table L.1: Items supplied with unit
Euro B/S 021/1 GB_Pro
Item Quantity Description
1 1 Boiler
2 1 Flue restriction rings
3 1 Cold water inlet valve
5 1 Copper tail for hot water outlet connection
6 1 Template
4 3 Flow and return service valve, gas service valve
7 1 Guarantee Card and Benchmark log book
8 1 Installation and connection accessories and
PRV packages incl. DHW outlet union nut
9 3 Installation and Servicing, Users and Flue Installation
Instructions
10 1Hanging bracket

5
INTRODUCTION
The TURBOmax Pro 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 and 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,
expansion vessel and diverter valve.
The TURBOmax Pro has an output for
domestic hot water of 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. Two types of
flue system are available, rear flue
outlet, top outlet (with turret)
concentric flue system (100 mm
outside diameter) and an extended
concentric flue system (125 mm
outside diameter). Flue extensions and
additional bends and elbows are
available for both flue systems to
increase the siting flexibility. The
boiler is not suitable for external
installation.
This boiler is available in Natural
Gas. An optional LPG conversion kit
is available.
If desired, an inhibitor may be used
in the system. Guidance on the use of
inhibitors is contained in these
instructions.
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 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.
TURBOmax Pro combination boilers
have a built in diagnostic system
which indicates the operational status
of the boiler. This feature provides key
information to aid commissioning and
fault finding.
The data badge is fitted on the rear
of the control panel.
See text of General Requirements for
installation requirements or notes.
Vaillant ltd. support the Benchmark
initiative. Within the information
pack, you will find a Benchmark Log
Book. It is very important that this is
completed correctly at the time of
installation, commisioning and hando-
ver to the user.
Note: This boiler must be installed
and service by a competent person
in accordance with the Gas Safety
(Installation and Use) Regulations
1998. In the UK „CORGI“
registered installers undertake the
work to a safe and satisfactory
standard.
General Information
EC designation
TURBOmax Pro boilers (VUW GB
282/2-3) carry the „CE“ Mark. This
demonstrates that the boilers fulfil 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
(89/336/EEC), the Low Voltage
Directive (72/23/EEC), the Boiler
Efficiency Directive (92/42/EEC) and
the Boiler (Efficiency) Regulations
1993.

6
BOILER SPECIFICATION
Technical data
TURBOmax Pro 28/2 E
( VUW GB 282/2-3) Units
CH heat output range (80/60 °C) 10.4 - 28
(35 500 - 95 500) kW (Btu/h)
DHW heat output 28 (95 500) kW (Btu/h)
DHW flow rate ∆T =35 °C rise 11.5 l/min
DHW flow rate at factory set temperature rise (∆T 42 °C) 9.5 l/min
Mains water pressure required for max. flow rate 0.5 bar
Minimum water flow rate 1.5 l/min
Mains water pressure required for min. flow rate 0.15 bar
Maximum inlet water pressure 10 bar
Inlet gas working pressure required (natural gas) 20 mbar
Gas burner pressure ignition rate 1.8 mbar
Gas rate max. (DHW) 3.3 m3/h
Weight 45 kg
Primary water content 2.0 l
Maximum CH heat input (net) 31.1 (106 200) kW (Btu/h)
Gas supply (G20) Gross CV (s.t.) 37.8 MJ/m3
Gas burner pressure max. rate 10.8 mbar
CH temperature flow range 35 - 82 °C
Minimum CH water flow (for 20 °C rise) 1203 l/h
Pump pressure available 0.25 (25) bar (kPa)
Expansion vessel pre-charge pressure 0.75 bar
Maximum CH system pressure 3 bar
Electrical supply 230/50 V~/Hz-
External fuse 3 A
Power input 150 W
Maximum DHW heat input (net) 31.1 (106 200) kW (Btu/h)
Case height 800 mm
Case width 440 mm
Case depth 338 mm

7
BOILER SPECIFICATION
Boiler connections
0
7
6
310
592
145
6
5
100
100
35 35
432
130 180
1
148
8
543 21
Fig. B.1: Connection diameters
Euro B/S 024/2
Key:
1Heating system return
(22 mm compression)
2Cold water connection with shut
off valve (15 mm compression)
3Gas connection (15 mm
compression)
4Hot water connection
(15 mm tail)
5Heating system flow
(22 mm compression)
6Flue outlet (100 mm flue with
turret)
7Hanging bracket
8Rear flue outlet

8
BOILER SPECIFICATION
C
C
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
17
16
18
19
21
22
23
24
25
26
27
28
29
30
31
Functional Diagram
1Air duct
2Fan
3Main heat exchanger
4Temperature sensor (NTC I)
5Flame sensing electrodes
6Modulating burner
7Fully modulating automatic gas
value
8Maximum hot water temperature
control
9Maximum radiator temperature
control
10 Diverter valve
11 DHW heat exchanger
12 Automatic bypass valve
13 CH flow service valve
14 Hot water outlet
15 Gas service valve
16 Service valve
17 Service valve
18 Pressure relief valve
19 Aqua sensor (DHW flow switch)
21 Main on/off control
22 Pressure gauge
23 Indicator lights
24 Expansion vessel
25 Expansion vessel charging valve
26 Circulating pump
27 Automatic air vent
28 Ignition electrode
29 Temperature sensor (NTC II)
30 Air pressure switch
31 Flue gas duct
Fig. B.2: Functional Diagram
Euro B/S 196/0

9
GENERAL REQUIREMENTS
Ensure that ALL regulations
are observed.
Fig. R.1
Euro B/S 006/0_GB
Related Documents
The installation of the boiler must be
in accordance with the relevant
requirements of Gas Safety
(Installation and Use) Regulations
1998, Health and Safety Document
No. 635 (The Electricity at Work
Regulations 1989), BS7671
(IEE Wiring Regulations) and the
Water Supply (Water Fittings)
Regulations. 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
70 kW net:
- 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.
Institute of Gas Engineers Publication
IGE/UP/7/1998: 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 1998.
Preliminary remarks
This appliance should only be
installed in conjunction with a Vaillant
flue system.
Install the flue system as detailed in
the separate flue installation
instructions supplied with this boiler.

10
GENERAL REQUIREMENTS
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.
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 (IEE
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.
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
accordance with Institute of Gas
Engineers Publication
IGE/UP/7/1998 „Guide for Gas
Installation in Timber Framed
Housing“.
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.

11
GENERAL REQUIREMENTS
Top outlet flue system
(100 mm outside diameter)
The top outlet horizontal flue system
(Art. No. 303 807) is suitable for
installations up to 720 mm measured
from the centre of the boiler flue outlet
to the outside face of the wall.
Flue extensions are available to
extend this length up to 3.2 m. Both
90° bends and 45° elbows are also
available to increase siting flexibility.
A vertical flue system is also available
(Art. No. 303 800).
Refer to flue system installation
instructions for full details.
Rear outlet flue system
(100 mm outside diameter)
The rear outlet horizontal flue system
(Art. No. 303 817) is suitable for
installations up to 600 mm wall
thickness.
Extended top outlet flue system
(125 mm outside diameter)
A top outlet horizontal flue system of
125 mm outside diameter is also
available (Art. No. 303 609) and
can be used to achieve flue lengths of
up to 10 m. Both 45° and 90° bends
and elbows are also available to
increase siting flexibility.
A vertical 125 mm concentric flue
system is also available
(Art. No. 303 600).
Refer to flue system installation
instructions for full details.
Flue system
Note: The TURBOmax Pro boiler is
delivered ready for installation
utilising a top outlet flue assembly.
For installation with a rear outlet flue
assembly refer to the boiler flue
outlet adaptation instructions
supplied with the rear flue
accessory.
48
800
48
4
Fig. R.2: Art.-No. 303 807
LAS Euro B/S 037/0
48 1285
603
Fig. R.3: Art.-No. 303 800
LAS Euro B/S 036/0
800
Fig. R.4: Art.-No. 303 817
LAS Euro B/S 073/0
Fig. R.5: Art.-No. 303 609
GU LAZ 082/0
70
1103
70
15

12
GENERAL REQUIREMENTS
Flue termination
The following details refer to both
flue systems.
a. The terminal must be positioned
such that the products of
combustion can disperse freely at
all times.
b. 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.
c. If the terminal is fitted less than
2 m above a balcony, above
ground or above a flat roof to
which people have access then a
suitable terminal guard;
280 mm x 280 mm deep, must be
provided and fitted (made by
Tower Flue Components,
Tonbridge, TN9 1TB).
Note: Vertical flues must not
terminate within 600 mm of an
openable window, air vent or any
other ventilation opening.
Where a terminal is fitted less than
1 m below a plastic gutter or less
than 0.5 m below painted eaves or
any other painted surface then a sui-
table shield at least 1 m long should
be fitted to protect the surface.
A
BCD
A
G
H, I
FJ
BFM
L
L
KK
G
G
FF
E
A
A
Fig. R.6: Flue termination
Terminal position for fan-assisted flue (minimum distance) mm
A1) 300
BBelow gutters, soil pipes or drain pipes 25
CBelow eaves 25
DBelow balconies (below car port roof) 25
EFrom vertical drain pipes and soil pipes 25
FFrom internal or external corners 25
GAbove ground or balcony level 300
IFrom a terminal facing a terminal 1200
KVertically from a terminal on the same wall 1500
LHorizontally from a terminal on the same wall 300
MDistance from adjacent wall for vertical Flue 500
GW 595/2
JFrom an opening in a car port (e.g. door, window)
into a dweling 1200
HFrom a surface or boundary facing a terminal 600*
Directly below an openable, above an opening or
horizontal to an opening i.e. air brick, opening
window or other , etc
Table R.1. Terminal position for a fan assisted concentric flue (see fig. R.6)
1) In addition, the terminal should not be nearer
than 150 mm to an opening in the building fabric
formed for the purpose of accommodating a built-in
element such as a window.
* BS 5440-1 It is recommended that a fanned flue
terminal should be positioned as follows: a) at least
2m from an opening in a building directly opposite,
and b) so that the products of combustion are not
directly directed to discharge across a boundary.

13
GENERAL REQUIREMENTS
Cupboard or compartment
ventilation
TURBOmax Pro combination boilers
are very high efficiency appliances.
As a consequence the heat loss from
the appliance casing during
operation is very low. For cupboard
or compartment installations it is
therefore not necessary to provide
any high or low level permanent air
vents for cooling purposes.
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.
Electrical supply
A 230 V, ~ 50 Hz single phase
electricity supply fused to 3 Amp.
must be provided in accordance with
the latest edition of BS7671 (IEE
Wiring Regulations) and any other
local regulations that may apply.
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 doublepole switch with a 3 mm
contact separation on both poles may
be used.
This appliance must be earthed.

14
GENERAL REQUIREMENTS
Guide to system
requirements
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 cleansing
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 either
Sentinel, Betz Dearborn Ltd. Widnes,
Cheshire, WA8 8UD.
Tel: [phone]
or Fernox
Alpha-Fry Technologies
Tandem House
Marlow Way, Beddington Farm Road
Croydon CRO 4xS
Tel. [phone]
Fernox technical
help line 01799 550811
Filling and make up
The system should be filled with water
via a seperate filling point at a
convienient position on the heating
cicuit. 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).
Pressure relief valve
A pressure relief valve is provided
with the boiler. This safety device is
required on all sealed C.H. systems
and is preset at 3 bar and provided
with a 15 mm compression connec-
tion for a discharge pipe, which must
be of no less than 15 mm in diame-
ter. The Pressure Relief Valve must not
be used for draining purposes.
Pressure gauge
This is factory fitted to the boiler and
indicates the primary circuit pressure
to facilitate filling and testing.

15
GENERAL REQUIREMENTS
Expansion vessel
The 28 kW boiler incorporates a
10 litre expansion vessel which is
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 R.2.
Table R.2: Sizing of additional expansion vessel
Vessel Volume [L]
Initial system pressure (bar) 1.0 1.5
Pressure relief valve setting (bar) 3.0
Total water content of system
litres
25
50
100
125
150
175
200
225
250
275
300
325
350
375
400
425
450
475
500
2.7
5.4
10.9
13.6
16.3
19.1
21.8
24.5
27.2
30.0
32.7
35.7
38.1
40.9
43.6
46.3
49.0
51.8
54.5
3.9
7.8
15.6
19.5
23.4
27.3
31.2
35.1
39.0
42.9
46.8
50.7
54.6
58.5
62.4
66.3
70.2
74.1
78.0
For system volumes other than those given above,
multiply the system volume by the factor across 0.109 0.156

16
GENERAL REQUIREMENTS
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400
50
100
150
200
250
300
350
400
450
500
550
600
650
700
Volume flow [l/min]
Lift [mbar]
setting II
setting I
Fig. R.7: Pump specifications
Euro B/S_VC_011/0GB
Pump specifications Circulating pump
The circulating pump is included in
the boiler. The pump head available
for the heating system is shown in
fig. R.7.
System by-pass
A fixed 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.
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.
DHW expansion vessel accessory
A DHW expansion vessel kit (Art.No
306 237) is available as an optional
extra 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.

17
GENERAL REQUIREMENTS
150
5
200
500
5
I
0
0120
60
9030
°C
bar4
3
2
1
0
Euro B/S 022/1
440
800
338
I
0
0 120
60
9030
°C
bar
4
3
2
1
0
Euro B/S 023/1
General
Preparation of boiler location
Clearances required
Mount the boiler on a flat and vertical
area of wall of sufficient area for the
boiler plus the required clearances for
installation and servicing.
The clearances are as detailed below
and are shown on the installation
template supplied with the boiler:
- 150 mm below the boiler,
- 5 mm on either side of the boiler,
- 210 mm on top of the boiler,
- 500 mm in front of the boiler.*
* Clearance is only required to
enable easier access to the boiler
for servicing and may be provided
by an openable door, etc.
Selecting position of boiler
Refer to „Boiler location“ for
information regarding siting the
appliance. 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 the flue
termination section (see page 12)
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.
Note: If the boiler is to be fitted in a
timber framed building, it should be
fitted in accordance with Institute of
Gas Engineers Publication
IGE/UP/7/1998 „Guide for Gas
Installations in Timber Framed
Dwellings“.
Fig. I.2: Free space required for installation
Fig. I.1: Dimensions of boiler
Note: Should it be necessary to run
system pipework to above the boiler
within the width of the casing, use
the optional top connection
accessory spacing frame.

5
5
210
124163 03240/242/280/282/824/828 Pro/Plus
60/100
07/2000
124163_03
1
3
2
18
BOILER INSTALLATION SEQUENCE
Using boiler template
Fix the paper template to the wall
ensuring that the correct flue exit
point has been identified, ensure that
the template is vertical.
The template shows
- The position of the fixing holes for
the boiler mounting bracket (1).
- The position of the connections.
- The position of the flue exit hole.
- Upper hole (2) indicates top outlet
flue with flue turret facing
rearward.
- Lower hole (3) indicates rear out-
let flue exiting directly through
wall.
Mark the position of the hanging
bracket fixing holes (1).
Drill 2 holes Ø 8 mm for the hanging
bracket.
Identify correct flue exit.
Mark the centre of the selected air/
flue duct and its circumference, e.g.
by drilling through the template.
For installation of a rear exit outlet
please refer to the installation instruc-
tions of the rear exit outlet kit
(Art. No 303817).
Other flue options
Flue instructions for other flue systems
such as vertical RSF flues, flues run to
the side of the boiler and the use of
additional bends etc. are detailed in
the flue installation instructions
provided with the boiler.
Remove the template from the wall
and plug the drilled holes using the
wallplugs supplied.
Note: Use alternative fixing holes
where necessary.
Fig. I.3: Using Boiler template

I
0
3
320
131
22
26,5
27
131
105 105
1
2
0120
60
90
30
°C
bar
4
3
2
1
0
Euro B/S 043/1
19
BOILER INSTALLATION SEQUENCE
Fig. I.4: Fitting the boiler
Fitting the boiler
●Lift the boiler (3) up to the wall so
that it is slightly above the hanging
bracket (1).
●Lower the boiler slowly onto the
hanging bracket so that the cross
member at the rear of the boiler
fully engages onto the hanging
bracket.
Note: Lift the boiler from either side
at the bottom edge.
Install the flue system
Install the flue system (refer to
separate air/flue duct installation
instructions).
Fitting the boiler hanging
bracket
Fix the hanging bracket (2) to the wall
using the screws supplied. (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 bracket is secured to a
substantial part of the timber frame
capable of taking the weight of the
boiler.

3
I
0
2
I
0
90°90°
1
Euro B/S 041/1
Fig. I.5: Remove of boiler casing
20
BOILER INSTALLATION SEQUENCE
Removing boiler casing
●Turn both securing fasteners (1)
anti-clockwise by 90° to release
control panel.
●Lower control panel (2).
●Pull the case (3) forward at the
bottom to disengage from the
securing clips.
●Lift the case slightly to clear the top
locations and pull forward to
remove.