Worcester Bosch Highflow 3.5 RSF User guide

....-- ~ ~ ~ORCESTER--.
Highflow 3.5 RSF
ROOM SEALED FANNED FLUE MODEL
FLOOR STANDING COMBINATION BOILER FOR CENTRAL
HEATING
AND MAINS FED DOMESTIC HOT WATER
INSTALLATION AND
SERVICING INSTRUCTIONS
GC NUMBER 41 311 40
BOILER OUTPUT
To Hot Water
Maximum 23.4 kw (80,000 Btu/h)
To Central Heating
Minimum 8.8 kW (30,000 Btu/h)
Maximum 23.4 kW (80,000 Btu/h)
IMPORTANT: THIS APPLIANCE IS FOR USE WITH NATURAL GAS ONLY
THESE INSTRUCTIONS APPLY IN THE UK ONLY
THESE INSTRUCTIONS ARE TO BE LEFT WITH THE USER OR AT THE GAS METER
...__ _____ :::. ~ .rwoRCESTER _____ ...
Bosch Group

CONTENTS
INSTALLATION REGULATIONS AND TECHNICAL DATA
Section 1
Section 2
Section 3
Section 4
Section 5
Section 6
Section 7
Section 8
Section 9
Section 9.1
Section 9.2
Section 9.3
Section 10
Section 11
Section 12
Section 13
Section 14
Section 15
Section 16
Section 17
Section 18
Section 19
Section 20
General Information
Siting the Appliance
Removal of Cabinet
System Considerations
Air Supply - Horizontal Flues
Terminal Position - Horizontal Flue
Air Supply - Vertical Flue
Connection of Primary and Secondary Vertical Flues
Installing the Appliance - General
Rear Horizontal Flue Outlet
Vertical Flue Systems
Pre-plumbing of the Appliance
Completion of the Installation
Sealed Primary System - Open Vent Secondary System
Open Vent Primary System ~ Mains Feed Secondary System
Mains Feed Domestic Hot Water Supply (Secondary)
Electrical
Commissioning the Appliance
System Guidance and Bypass Adjustment
Users Instructions
Routine Cleaning and Inspection
Replacement of Parts
Short Parts List
Fault Finding Chart
INSTALLATION REGULATIONS
The installation of this appliance must be in accordance with the relevant requirements of the Gas Safety (Installation and
Use) Regulations, local Building Regulations, Building Standards (Scotland) (Consolidation), current lEE wiring
regulations and bye laws of the local water undertaking. It should be in accordance with the relevant recommendations of
the following British Standards and Codes of Practice: BS 6798:1987, BS 5449:1:1990, BS 5546:1:1990, BS 5440:1:1990,
BS 5440:2:1989 and BS 6891.
Gas Safety
(Installation and Use) Regulations 1984: It is the law that all gas appliances are installed by a competent
person, in accordance with the above regulations. Failure to install appliances correctly could lead to prosecution. It is in
your interest, and that of safety to ensure compliance with the law.
The manufacturers notes must not be taken, in any way, as overriding statutory obligations.
TECHNICAL DATA NOTE: THE DATA PLATE IS POSITIONED INSIDE THE APPLIANCE AT THE FRONT LEFT
HAND SIDE.
Table 1
NOMINAL BOILER RATINGS (10 minutes after lighting)
BURNER SETTING
MODE
OUTPUT INPUT PRESSURE GAS RATE
kW
(Btu/h) kW
(Btu/h) m bar (in. wg)
m3 /h ift'ih I
8.79 (30000) 12.0 (40955) 2.2 (0.88) 1.11 (39.4)
11.0 (37545) 14.7 (50170) 3.2 (1.28) 1.36 (48.3)
HEATING 13.0 1443701 17.1 (58360) 4.4 (1.76) 1.59 (56.2)
RANGE 15.0 151195) 19.6 (66555) 5.8 (2.32) 1.81 (64.0)
17.0 (58020) 21.9 (74745) 7.3 (2.92) 2.03 (71.9)
19.0 (64845) 24.2 (82595)
9.1
(3.64) 2.25 (79.5)
23.44 (80000) 29.3
(1 00000) 14.3 (5.72) 2.72 (96.2)
DOMESTIC 23.44 (80000) 29.3
(1 00000) 14.3 (5.72) 2.72 (96.2)
HOT WATER
Note: The pressure test point is located on the gas valve (See fig. 31a).
2

Table 2
SPECIFICA nONS
HEATING FLOW
28mm COPPER TUBE
HEATING RETURN
28mm COPPER TUBE
SAFETY VALVE
22mm COPPER TUBE
COLD FEED
22mm COPPER TUBE
COLD WATER MAINS IN 15mm COMPRESSION -SUPPLIED
DOMESTIC WATER OUT
22mm COPPER TUBE
GAS INLET 22mm COPPER TUBE
HEIGHT
860mm (33.9in)
WIDTH
550mm (21.6inl
DEPTH
600mm (23.6in)
WEIGHT 95kg (2101b)
empty- 147kg (3241b) full
PRIMARY CAPACITY 48 litres (10.6 gal)
*MAXIMUM STATIC HEAD
25m (81ft.)
*MINIMUM STATIC HEAD 1000mm (39in)
CIRCULATING PUMP
Grundfos 15-60
EXPANSION VESSEL 12 litres charged 0.5 bar
OUTPUT TO HEATING MAXIMUM 23.4kW (80,000 Btu/h)
OUTPUT TO DOMESTIC HOT WATER 23.4kW (80,000 Btu/h)
CH CONTROL THERMOSTAT- MAX. TEMPERATURE Nominally 82°C (180°F)
DOMESTIC HOT WATER FLOW
RATE (35°C RISE) Nominally 9.6 litres/min + 15% (2.1 gal/min)
MAXIMUM DOMESTIC HOT WATER FLOW RATE Nominally 15 litres/min (3.3 gal/min) ±15%
* Appliance static heads are measured from the top of the casing to the highest point of the system (See Fig_s. 24. and 25)
Table 3
HORIZONTAL VERTICAL
FLUE DETAILS- See Notes Below REAR FLUE PRIMARY FLUE
WALL OR
CEILING- HOLE DIAMETER FOR AIR DUCT 125mm (Sin) 125mm (Sin)
WALL HOLE DIAMETER FOR SEALING RING 150mm (6in)
MINIMUM FLUE LENGTH- STANDARD FLUE KIT 100mm (4in) 1557mm (61.3in)
MAXIMUM FLUE LENGTH- STANDARD FLUE KIT 1
OOOmm (39in) 2000mm (73in)
FLUE LENGTHS WITH EXTENSION KIT 1
001 to 2000mm
2001 to 3000mm
(39 to 73in) (79
to 118in)
If a flue extension is required (See Section 9) it may be obtained from Worcester Heat Systems Ltd. ONE EXTENSION
FLUE KIT ONLY MAY BE USED PER APPLIANCE. Part No. ZAGAS066
Table 4
AVAILABLE PUMP HEADS
HEATING OUTPUT HEAD MIN. FLOW RATE OPTIMUM
kW Btu/h METRES
FEET
LITRES/MIN.
GALUMIN. TEMPERATURE RISE
8.8 (30,000)
5.1
16.6
8.41
1.89
11
(37,500) 4.7 15.5
10.51
2.36
13
(44,350) 4.3 14.1
12.42 2.79 15°C between
15
(51,200) 3.8 12.6 14.33 3.22
heating flow and return
17
(58,000) 3.3 10.9 16.24 3.65
19
(64,800) 2.2 7.2 18.15 4.08
23.4 (80,000) 1.5 5.0 22.35 5.02
3

1. GENERAL INFORMATION
IMPORTANT: Although the appliance includes the facility
to instal a sealed primary water system and feed the sec-
ondary system via the mains supply, only one of these
can be used, i.e. the system arrangement must be one of
the following:
(i) Sealed primary and open vented (i.e. cistern feed)
secondary (Section 10) or
(ii) Open vented primary and mains feed secondary
(Section 11) or
(iii) Open vented primary and open vented (i.e. cistern
feed) secondary.
FOR FURTHER ADVICE CONTACT WORCESTER HEAT
SYSTEMS LTD.
1. HIGHFLOW 3.5 RSF INCORPORATES
(a) An induced draught fan, a low thermal capacity heat
exchanger having a maximum heat output of
23.4kW (80000 Btu/h).
(b) Either a horizontal (rear outlet) or vertical fanned
flue system -to order.
(c) A standard duct kit for horizontal flue lengths from
100mm {4in) to 1000mm {39in). (An extension duct
kit from 1001 mm (39in) to 2000mm {79in) maximum
length is available as an option).
A standard duct kit for vertical flues, complete with
diverter intended for installation within a roof space.
The kit will enable the diverter to be installed be~
tween 1557 (61.3in) and 2000mm (79in) above the
appliance top outlet. (An extension duct kit from
2001mm (59in) to 3000mm {118in) is available as an
option).
(d) A heatbank having a nominal capacity of 45 litres
(10 gallons) of circulating primary hot water posi-
tioned inside the appliance. A copper finned water
to water heat-exchanger is fitted into the heatbank.
Secondary supply domestic hot water passes
through the heat exchanger.
{e) A diverter valve to direct the boiler output either to
domestic hot water or central heating as required.
(f) A circulating pump.
(g) A multifunctional HIGH/LOW gas valve and elec-
tronic control system to control individually the
domestic hot water and central heating. The system
provides automatic ignition.
(h) Boiler and hot water temperature control thermo-
stats providing control for central heating and dom-
estic hot water.
(j) A User/s Operating Switch for selection of water only
or heating and water. A programmer kit is available
as an optional extra.
(k) An expansion vessel, pressure gauge, pressure relief
valve and auto air vent to enable the primary circuit
to be connected to a sealed water system.
{I) An electronic pump delay control board which en-
ables the pump to run on for a period of about 5 min-
utes after each operating cycle.
2. INSTALLATION WARNING:
GREAT CARE MUST BE TAKEN TO ENSURE THAT
NO FOREIGN MATTER IS LEFT IN THE WATER
SYSTEM. THIS COULD CAUSE DAMAGE TO THE
APPLIANCE.
3. NATURAL GAS SUPPLY
The boiler requires 2.72m'/h (96.2ft'/h) of gas. Meter and
supply pipes must be capable of delivering this quantity of
gas
in addition to the demand from any other appliances
in tho house. The meter outlet governor must ensure a
nominal pressure of 20 mbar (Bin wg) at the appliance,
equivalent to a pressure of about 18:5-19
mbar at the gas
valve. The complete installation, mcluding the meter,
should be inspected and tested for soundness and purged
in accordance with the recommendations of BS 6891.
4
4. ELECTRICAL SUPPLY
Mains supply 240 V, ........ 50 Hz, 160 watts fused at 3A.
See Section 13. The length of supply cable provided
with the appliance is rated at a temperature of aooc
continuous.
5. OPEN VENTED SYSTEM
The appliance is supplied ready for connection to a
sealed water system. An open vented system can be
used by carefully removing the safety valve and seal-
ing its connection. See Section 11. Care should be
taken not to distort the pipe.
6. CONTROLS
All controls included with the appliance are specified
in the 'Short List of Parts' included in this leaflet.
There is provision for a room thermostat and frost
thermostat to be fitted to the appliance. See Section
13.
Thermostatic radiator valves can be used in the
system; however, a suitable by-pass is essential with
this type of control. See Section 15.
7.
DRAINAGE
A drain cock is fitted in the pipe connecting thE!
primary heat bank to the sealed system expansion
vessel to drain water from the boiler and the heat
bank. (Fig. 46)
8. PACKAGING
The appliance is despatched in one package. A sep-
arate package contains either the standard horizontal
or vertical flue kit. Each kit includes either a balanced
flue terminal (horizontal flue) or diverter (vertical
flue) together with the necessary duct work, sealin~1
materials, etc.
2. SITING THE APPLIANCE
(Refer also to sections 5, 6, 7 and 8).
1. The appliance is floor standing and the floor
must be firm
and level.
2. The following clearances must be left to allow for
servicing and ventilation:
(a) Above the appliance: Servicing 450 mm (18 in.)
Ventilation 5 mm (0.2 in.)
(b) In front of the appliance: Servicing 600 mm (24 in.)
Ventilation 75
mm (3 in.)
(c) Left and right-hand side: Servicing 20
mm (0.8 in.)
Ventilation 20 mm (0.8 in.)
NOTE: Care must be taken to ensure adequate space is
available at either side for installing the boiler. See Sec-
tion 9.
3. The chosen position must allow the provision of a
satisfactory balanced flue termination. See Section 6,
if a horizontal flue system is to be used OR
4. The chosen position must allow the provision of a
satisfactory secondary flue terminal discharge in a
down draught free zone. See Section 8, if a vertical
flue system is to be used.
NOTE: If the appliance is to be fitted in a timber framed
building it should be fitted in accordance with the British
Gas publication "Guide for Gas Installation in Timber
Framed Housing" Ref DM2. If in doubt advice must b~3
sought from the local Region of British Gas.
3. REMOVAL OF FACIA PANEL
AND CABINET
See Fig. 1.
NOTE: It is necessary to remove the cabinet top cover,
front cover, and may be necessary to remove the facia
panel, left and right hand side panels and lower grille to
aid installation.

Fig. 1 Cabinet - Control Panel and Facia Fixing Screws
A
A TOP
COVER RETAINING LUGS
B TOP
COVER FIXING BOLT
c FACIA FIXING SCREWS
D DHW AND CH THERMOSTAT
MOUNTING BRACKET FIXING SCREWS
E CONTROL PANEL FIXING SCREWS
F CONTROL PANEL SUPPORT BRACKET
AND SCREW
G
LEFT HAND SIDE PANEL FIXING SCREWS
H SIDE PANEL BRACKET FIXING SCREWS
J RIGHT HAND SIDE PANEL FIXING SCREWS
K LOWER FRONT GRILL
KICKSTRIP FIXING SCREWS
L FRONT COVER {NO FASTENINGS)
""
(a) Remove the cabinet front cover by pulling firmly at
the base and lifting upwards and outwards.
Remove the cabinet top cover by slackening com-
pletely the bolt 'B' retaining the front of the top
cover. See Fig. 1.
(b) Pull up the front edge of the cover sharply to
disengage the fasteners. Draw the cover forward
enough to disengage it at the rear and lift clear.
(c)
Undo the five screws 'K' holding the lower front
grille kick strip.
(d) Pull off the two thermostat knobs and remove the
five screws 'C'; two securing the ends of the facia to
the side panels and three underneath the facia, fixing
it to the base of the control panel. Pull the facia
forward until it clears the side panels. The facia will
come away complete with three position switch or
programmer, if fitted. Support the facia having
drawn it forward enough to gain access to the plug
in terminal rail positioned behind and to the right of
the heating thermostat. The terminal rail is
numbered 14 to 17 inclusive. Separate the two
halves of the terminal rail, enabling the facia to be
removed completely. (Fig. 37)
(e)
Remove the two remaining posidrive screws 'C'
retaining the top of the left hand side panel and the
two M5 slotted head screws and single posidrive
screw retaining the top of the right hand side panel
'J'. Draw the side panels forward and lift out.
NOTE: The control panel is supported in position by a
single posidrive screw 'F'. (See Fig. 1). This is intended
to hold the panel during installation only and no undue
strain should be placed on the panel.
4. SYSTEM CONSIDERATIONS
(a) The appliance includes a pump and no other
circulating pump is required. When fitting a room or
frost thermostat, refer to Section 13, Electrical. The
appliance will operate satisfactorily on a two pipe small
bore or micro-bore system.
5
J,C
c L
K
(b) The heatbank contains a finned copper heat
exchanger which provides domestic hot water. A
control system is incorporated that gives priority to
the domestic hot water and the central heating will
be turned off when a demand for hot water is made.
For large quantities of hot water the control
thermostat should be set at maximum and after
use, a few minutes may be required to re-heat the
heatbank. The central heating will remain off during
this period.
IT IS ESSENTIAL TO FIT A BYPASS TO ALL
SYSTEMS.
5. AIR SUPPLY HORIZONTAL FLUE
1. The room in which the appliance is installed does
not require a purpose air vent.
2. If the appliance is installed in a cupboard or
compartment, permanent air vents are required in
the cupboard or compartment, one at high level, and
one at low level, either direct to outside air or to a
room. Both high and low level air vents must
communicate with the same room or must both be
on the same wall to outside air. The minimum
effective areas required are given in Table 5.
Table 5 COOLING AIR REQUIREMENTS
HORIZONTAL AND VERTICAL FLUE SYSTEMS
Position of Air from
Air direct
Air Vents room from outside
High Level 264cm
2
132cm
2
{41 in
7)
{20.5in
2)
Low Level 264cm
7
132cm
2
(41 in2) (20.5in
7)

6. FLUE TERMINAL POSITION-
HORIZONTAL FLUE
IMPORTANT
1. Flue length. See note in Section 1, General Informa-
tion, regarding standard flue assembly and extension
flue.
2. The flue must be installed in accordance with the
recommendations of BS 5440:Part 1.
Minimum siting dimensions for positioning the balanced
flue terminal:
TERMINAL POSITION (See Fig. 2) MIN DISTANCE
A-
Directly below an open able
window or other opening, e.g. air
brick 300mm
(12in)
B-
Below gutters, soil pipes or
drain pipes 75mm
(3inl
c-
Below eaves 200mm
(Sin)
D-
Below balconies or car port roof 200mm
(Bin)
E- From vertical drain pipes and
soil pipes 75mm
(3in)
F -
From internal or external corners 300mm
(12in)
G -
Above ground, roof or balcony
level
300mm
(12in)
H- From a surface facing a terminal 600mm
(24in)
1-
From a terminal facing a terminal
1200mm
(47inl
J -
From an opening in a car port
(e.g. door, window) into dwelling 1200mm
(47in)
K- Vertically from a terminal on
the same wall
1500mm (59in)
L -
Horizontally from a terminal on
the same wall 300mm (12inl
GENERAL NOTES
1. The terminal must be positioned such that the com-
bustion products can disperse freely at all times.
2. In certain weather conditions a terminal may steam
and positions where this could cause a nuisance
should be avoided.
3. If the terminal is fitted within 850mm of a plastic
gutter or within 450mm of painted eaves, an alumi-
nium shield of at least 750mm long should be fitted
to the underside of the gutter or painted surface
(Dimensions 8 and C in Fig. 2).
4. If a terminal is fitted less than 2 metres (78.6in)
above a surface to which people have access then a
suitable guard must be provided. A terminal protect-
ive guard is available from: Tower Flue Components
Limited, vale Rise, Tonbridge, TN9 1TB. Terminal
Guard Reference: GC 393 553- Type K2.
The terminal guard must be securely fixed to the wall
using the three brackets provided, suitable plugs and
corrosion resistant screws. The guard must be sym-
metrically positioned about the terminal assembly
and spaced such that there is a gap of 50mm min-
imum between the end of the terminal and the guard.
5. The air inlet/products outlet duct and the terminal of
the boiler must not be closer than 50mm (2 in) to
combustible material. Detail recommendations on
protection of combustible material are given in BS
5440:1 1990, sub-section 3.3
IMPORTANT
It is absolutely ESSENTIAL to ensure, in practice,
products of combustion discharging from the
terminal cannot re-enter the building or any other
adjacent building through ventilators, windows,
doors, other sources of natural air infiltration or for-
ced ventilation/air conditioning. If this eventuality
should occur, the appliance MUST be turned off
immediately and the problem rectified.
6
7. AIR SUPPLY VERTICAL FLUES
1. The room in which the appliance is installed does not
require a purpose air vent.
2. If the appliance is installed in a cupboard or
compartment, permanent air vents are required in
the cupboard or compartment, one at high level, and
one at low level, either direct to outside air or to a
room. Both high and low level air vents must com-
municate with the same room or must both be on the
same wall to outside air. The minimum effective
areas required are given in Table 5, COOLING AIR
REQUIREMENTS, Section 5.
3. ALL installations must be provided with purpose
designed air vents in the roof space, communicating
direct with outside air.
THE MINIMUM EFFECTIVE AREA REQUIRED FOR AIR
VENTS WITHIN A ROOF SPACE IS 516cm
2 (80in2).
4. The roof space containing the diverter must be
sealed off completely from:-
(a) the room, cupboard or compartment in which the
appliance is installed and
(b) any other room.
8. CONNECTION OF PRIMARY AND
SECONDARY VERTICAL FLUES
The components up to and including the draught diverter
are supplied and these must be installed vertically above
the top boiler flue outlet, in accordance with the dim-
ensions shown in Fig. 3. Note that the draught diverter
must be positioned such that it will not be obstructed by
such as loft insulation.
A secondary flue must be fitted to the top of the draught
diverter. This component will accept flue pipe to BS 715
size 125mm (5in). If flue pipe to BS 4543 is used, then an
adaptor will need to be fitted, but the nominal internal
diameter must not be decreased. The installation of the
complete flue system must be in accordance with BS
5440:1.
The secondary flue system must be adequately sup-
ported and the exit from the roof space water proofed.
Horizontal runs and bends should ideally be avoided, but
at least minimised, and a spillage test must be carried
out in accordance with BS 5440:1. Fig. 3 shows an ap-
propriate point at which to apply the test.
No part of the flue system shall be within 25mm (1.0in)
of combustible material.
Table 7
Max. secondary flue length Max secondary flue length
if set to minimum CH input if set to maximum CH input
6m (20ft) 1Om (33ft)
The flue lengths recommended above are intended to en-
sure that condensate does not form in the secondary flue
system when the appliance operates under all approved
operating conditions.
NOTE: The permanent, purpose designed ventilation
openings required within the roof space, the openings
within the diverter and any compartment ventilation - if
applicable- MUST NOT BECOME BLOCKED.
The user MUST be instructed not to store items within
the roof space which may cause an obstruction, or in the
compartment - if applicable.
A space of at least 250mm (10in) radius shall be provided
around the draught diverter with no obstructions (Fig. 3).

Fig. 2 Siting of terminal
Horizontal Flue
A'
/
j '
-'l
..
GJ
~
Dj
'
:.Ji
, , I I
l]
A
I
~
BC~ '
L'hl
IK
•
v .
IK
!
~
I I
F'
/
,,
llF
~HI' J
, I ' '
I. I \
~J
'j
F
r·E
Fig. 3 Position of Vertical Primary
Flue and Secondary Flue
See also Fig. 17
TERMINAL
(NOT SUPPLIED)
.•
TWIN WALL SEC. FLUE -------+
IS RECOMMENDED
DRAUGHT
T
DIVERTER WITH 125mm-------l-·f"=Y
(5in) SOCKET OUTLET ~
CLEAR SPACE 250mm (10in I
RADIUS AROUND ··1-.,+-~
DIVERTER WITH NO .. . M .
OBSTRUCTIONS
STANDARD FLUE KIT
MINIMUM HEIGHT H
1557mm (61.3in)
MAXIMUM HEIGHT H
2000mm (79in)
WITH EXTENSION
KIT
MAXIMUM HEIGHT
H ~ 3000mm (118in)
BOTTOM OF FLUE OUTLET
SOCKET
H
45mm:
(1.8in) 1;
l_
G
GENERAL GUIDANCE · SITING OF
VERTICAL FLUE
TERMINAL
CHIMNEY ON RIDGE
NOT ON RIDGE
PITCH
Dim. Y 1m (3.3ft)
EXCEEDING 30°
AT OR
ABOVE ROOF
ABOVE INTERSECTION
PITCH
NOT RIDGE Dim Y
250mm (lOin)
EXCEEDING 30° LEVEL ABOVE ROOF
INTERSECTION
NOTE: A spillage test must be carried out at the
diverter HERE,
in accordance with BS5440:1.
ROOF SPACE VENTILATED
TO OUTSIDE AIR SECTION 7.3
CEILING FLUE SEALING PLATE
860mm
(33.9in)
7

9.0 INSTALLING THE APPLIANCE
GENERAL
If a HORIZONTAL FLUE is to be installed refer to Sections
2, 5, 6, 9.1 and 9.3: also Figs. 2 and 4.
If a VERTICAL FLUE is to be installed refer to Sections 2,
7, 8, 9.2 and 9.3; also Fig. 3.
NOTE: MORE THAN ONE PERSON MAY BE REQUIRED
TO
INSTAL THE APPLIANCE.
The space required for installation is 50mm (2in) at the
left hand side and 150mm (6in) at the right hand side.
A
description given in Section 9.3 covers one method of
installation. If connections are made in a different way
then the space required for installation may be greater.
In some circumstances when installing the appliance,
particularly where minimum clearances for access and
servicing have been used, it may be found necessary to
pre-plumb the appliance and fit unions and stub pipes,
(Fig 5) to the boiler pipework before moving it into posi-
tion. If so refer to Section 9.3 and make the connections
before assembling the flue system. Check to determine
whether or not an extension kit is required. Refer to Sec-
tion 1(c) and Section 2.
A knock-out panel is provided in the cabinet top panel to
facilitate vertical pipe connections.
Compression fittings may be used on all water con-
nections to allow for the fitting of the boiler and servic-
ing.
1. Unpack the appliance.
2. Unpack the standard flue kit and flue extension kit (if
required) and check the contents against the en-
dosed check list. Ensure all cardboard packing in the
standard flue assembly and flue extension is re-
moved.
3. Remove the top cover and the front panel from the
cabinet as described in Section 3.
4. The boiler is supplied suitable for a horizontal rear
flue outlet configuration; the vertical outlets being
sealed off with blanking plates. If a vertical flue is re-
quired refer to Figs 6 and 7.
To gain access to the top flue outlet cover, first re-
move the access cover. Fig. 6.
Fig. 4 Wall preparation · Rear outlet
Dimensions mm (in) -1{~~
5
)r
1---- 600 {23.6) ~
.L~ 1:1.
r- -, I
r~~- I
' ' '
) ~----~
.,(--- --....J---....1 ~
,.-t..""_ !.._----- -- - - ~ ~
(a) Remove the top air duct and flue duct blanking
plates.
(b) Run a bead of silicone sealan1 around the inside of
the rear flue duct and air duct sockets.
(c) Fit
the blanking plate into the rear flue outlet socket,
push fully home and tighten the clamping screw,
working through the top air duct socket opening.
(d) Fit the rear air duct socket blanking plate, push it
fully into the socket and tighten the clamping screw.
NOTE: THE ACCESS PANEL MUST BE REPLACED WHEN
THE FLUE SYSTEM IS FITTED.
REFER TO SECTION 9.2a {STANDARD FLUE KIT) OR 9.2b
{EXTENSION KIT) Subsection 3{a).
9.1. REAR HORIZONTAL FLUE
1. Take account of the requirements under Section 2 -
Siting the appliance.
Refer to page 1 and Fig 4. Mark the flue position re-
quired on the wall. Cut a hole in the wall 125mm (5in)
diameter.
NOTE: If a core boring tool is not used and the hole
is made oversize, it must be reduced to 130mm max-
imum diameter and the inner skin of the brickwork
made good before the appliance is installed (Sec-
tions 9.1a; 9.1b; 9.1c).
2. Determine the flue length by referring to the app-
ropriate section below, which details the correct flue/
boiler assembly procedure.
Section
9.1a.
9.1b.
9.1 c.
Length L
100mm-1000mm (4in-39.4in)
1001 mm-1200mm (39.4in-47.2in)
1201 mm-2000mm (47.2in-78.7in)
NOTE: REFER TO SECTION 9.3. COMPLETE THIS PART
OF THE
INSTALLATION AS NECESSARY BEFORE
ASSEMBLING THE REQUIRED FLUE ARRANGEMENT.
TOP AIR DUCT SOCKET
{DEPTH
18mm {0.7in)
HOLE CUT THROUGH WALL
TO ACCEPT REAR AIR DUCT
WALL THICKNESS TO
INCLUDE
ANY SURFACE
FINISH, INSIDE
OR OUTSIDE
REAR AIR DUCT SOCKET
{DEPTH
18mm {0.7in)
INSIDE
PLASTER
DIMENSIONS ON PAGE 1 MAY
VARY DEPENDING ON WHETHER
ANY FLOOR COVERING IS
REMOVED AND/OR INSULATING
SHEET IS PLACED BETWEEN THE
APPLIANCE AND THE FLOOR
FLOOR LEVEL
8
OUTSIDE
RENDERING
IF APPLIED

Fig. 5 Rear View of Boiler Pipework and Flue
Connections
NOTE: ALL DIMENSIONS ARE NOMINAL mm (in)
A CENTRAL HEATING RETURN (28mm)
B SAFETY VALVE (22mm)
C GAS INLET (22mm)
D DOMESTIC COLD WATER
IN- R'h ('/,in BSP)
E DOMESTIC HOT WATER OUT (22mm)
F CENTRAL HEATING FLOW (28mm)
G VENT AND FEED (22mm)
H REAR FLUE CONNECTION (Centrelines)
=
I
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r --~
r--:_:
I ~
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-:-·. ~
•
---
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~..,
H 377mm (14.81n) ___,
--550mm {21.6in)-- -1
G & B200mm (7.9in)
D 170mm (6_7in)
E 135mm (5.3in)
F 90mm (3.5~n}
A 60mm (2.4in)
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Fig. 7 Flue/Air Duct Socket Clamping Screws
NOTE: A SIMILAR METHOD
IS USED TO CLAMP THE
REAR AIR DUCT.
ACCESS TO THE SCREW
IS FROM THE TOP (FIG 6)
VERTICAL AIR DUCT
CLAMPING SCREW
_.---- VERTICAL AIR
__ _;;;____ DUCT SOCKET
REAR FLUE DUCT
CLAMPING SCREW
Fig. 6 Interchanging Positions of Air Duct/Flue Duct Outlet Blanking Plates
FLUE DUCT HOUSING
REAR FLUE DUCT BLANKING
PLATE POSITION
9
APPLY SEALANT AROUND INSIDE
OF FLUE AND AIR DUCT SOCKETS
tr
REAR AIR DUCT
BLANKING PLATE
POSITION
I

9.1 a BOILER FLUE ASSEMBLY
REAR OUTLET
100mm-1000mm (4in-39.4in}
NOTE: An extension kit is NOT required.
1. Cut the air duct to length as follows:-
(a) Measure the wall thickness Land add 28mm (1.1in).
(Fig 4, 8
and 15). This is the overall length of 110mm
(4.5in) diameter air duct required.
(b) Reduce the air duct 'A' to L + 28mm (1.1in). Note.
that one end of the duct has two holes drilled. DO
NOT CUT FROM THIS END OF THE DUCT.
2. Cut the flue duct to length as follows:-
(a) Take wall thickness Land add 51mm (2.0in). This is
the overall length of 60mm diameter (2.38in) flue
duct required.
(b) Reduce the flue duct to 'C' to L + 51mm (2.0in) by
cutting from either end. (Fig 9).
3.
Refer to Figs 6 & 7. Slacken the vertical air duct clam-
ping screw sufficient to allow the air duct blanking
plate to be pulled out of its socket. This will facilitate
access to the rear flue duct clamping screw.
Depending on wall thickness and space available the
flue duct only should either:-
(a) Be passed through the wall from outside and then
fixed into the socket at the rear of the flue duct
housing (Fig 8) or
(b) If the flue duct is relatively short e.g. less than
400mm {16in) it may be fixed directly to the flue
duct housing prior to moving the boiler into posi-
tion in front of the inner wall face. (Fig 8).
4. Remove the backing paper from the square sealing
gasket provided. Position the gasket as shown, then
press the adhesive backed side firmly against the
back panel, around the rear flue outlet (Fig 8).
Either
(a) Apply a bead of silicone sealant around the inside of
the rear flue duct socket and around the inside of
the rear air duct socket. Move the appliance into
position, square to the wall face, standing centrally
in front of the hole in the wall. Position the back
pane140mm {1.6in) in front of the watl face. Pass the
flue duct through the wall and push the end fully
home into the rear flue duct socket. Working
through the top air duct socket tighten the rear flue
duct clamping screw. Make sure the flue duct is pos-
itioned concentrically within the rear air duct socket
and the hole in the wall.
or
(b) Push one end of the flue duct fully home into the
rear flue duct socket. Working through the top air
duct socket tighten the rear flue duct clamping
screw. Make sure the flue duct is positioned con-
centrically within the rear air duct socket.
Move the appliance into position, square to the wall
face, with the back panel about 40mm (1.6in) in
front of the wall. Allow the flue duct to pass into the
hole and check the duct is positioned concentrically.
5. Fit the flue terminal into the end of the air duct with
holes. Slide the flue terminal into the air duct up to
the rolled stop channel. Using the holes in the air
duct as a guide drill through the flue terminal with
the 3mm drill supplied. Screw the assembly together
with two No 6 x 10mm self-tapping screws provided.
(Fig 10).
6. RECHECK THAT ANY STUB PIPE CONNECTIONS RE-
QUIRED HAVE BEEN MADE. (SECTION 9.3).
7. Working from outside pass the air duct and terminal
assembly through the hole. A flue expansion joint of
about 100mm {4in) is allowed for. The short section
of flue duct inside the terminal will engage and push
over the section of flue duct connected to the boiler,
provided the air and flue duct have been cut ac-
curately.
10
Fig. 8 Rear Flue Application
FLUE DUCT HOUSING
PLAN VIEW
,,
"
CLAMPING ,..--------------,\1
SCREW
P~b.R
FLUE
OUTLET
SOCKET
SEALANT
SEALING
GASKET
BLANKING PLATE
REMOVED FROM TOP AIR
DUCT INLET SOCKET
TOP AIR/FLUE DUCT
CLAMPING SCREWS
BLANKING PLATE "
FITIED IN TOP FLUE
OUTLET SOCKET
ACCESS PANEL, WITH
M5 SLOTIED HEAD FIXING
SCREW FOR TOP FLUE OUTLET CLAMPING SCREW
REAR AIR DUCT /
CLAMPING SCREW
OUTER
WALL
FACE
POSITION
SEALING GASKET
AROUND REAR FLUE OUTLET AS SHOWN
Fig.Ba OUTER
WALL
SEALING GASKET
/