PowerMax OV 140 P Series, 140 Series, 155x Series, OV 140 CP, SS 140 P Installation And Servicing Instructions

Publication No. P443 - 12/05

BAXI POTTERTON
BROWNEDGE ROAD
BAMBER BRIDGE
PRESTON PR5 6SN
(Technical Helpline) TEL [phone]
(Service) TEL [phone] FAX [phone]
(Spares) TEL [phone]

“Powermax” is a trademark of Baxi Group Ltd

The code of practice for the installation, commissioning

& servicing of central heating systems

Guide to Panel Removal

Auto vent access

Main power supply

cable entry

Upper front panel and

retaining screw

Lower front panel

(2 screws)

Lifting and plumbing

access each side

External controls

cable entry

Top panel

Plinth (4 screws)

MAIN POWER SUPPLY

CABLE ENTRY

TRANSIT SCREW

EXTERNAL CONTROLS

(AND IMMERSION

HEATER CABLE ENTRY)

PLUMBING ACCESS

EACH SIDE

LIFTING AND PLUMBING

ACCESS EACH SIDE

AUTO VENT ACCESS

TOP PANEL

(2 SCREWS)

FRONT PANEL
(2 SCREWS)

PLINTH
(4 SCREWS)

Guide to panel removal

140

155

xx

SAFETY NOTICE

In your own interest and that of safety, it is the law that all gas appliances
are installed and serviced by competent persons in accordance with Gas
Safety (Installation and Use) Regulations 1998. This appliance requires
annual checking or servicing and this should be entrusted to a CORGI
Registered Installer. All CORGI Registered Installers carry a CORGI ID
card and have a registration number. Both should be recorded in your
central heating log book. You can check your installer is CORGI
registered by calling 01256 372300.

INSTALLATION AND SERVICING
INSTRUCTIONS

TO BE LEFT WITH BOILER - READ THESE INSTRUCTIONS BEFORE INSTALLING OR
LIGHTING THE BOILER

The code of practice for the installation, commissioning

& servicing of central heating systems

140 and 155

xx

POWERMAX OPEN VENT MODELS :

OV 140 P OV 155x P WITH FITTED PUMP
OV 140 CP OV 155x CP WITH FITTED PUMP & PROGRAMMER

POWERMAX SEALED SYSTEM MODELS :

SS 140 P SS 155x P WITH FITTED PUMP
SS 140 CP SS 155x CP WITH FITTED PUMP & PROGRAMMER

2

THIS APPLIANCE IS FOR USE WITH NATURAL GAS ONLY.

Contents

Section Page

1. Safety Regulations 2

2. Description 2-3

3. Natural Gas Supply 3

4. Electric Supply 3

5. Siting the Appliance 3-4

6. Flueing Options 4-5

7. Ventilation Requirements 6

8. Technical Data 6

9. Installing the Appliance 6-7

10. Electrical Connection to the Appliance 8
Wiring Diagrams 9

11. Water Supply / Primary System 10-11

12. Commissioning 14-15

13. Servicing Instructions 16-18

14. Fault Finding 12

15. Functional Flow Diagrams 13

16. Short List of Spare Parts 19

17. Installing an Extended Balanced Flue 20-21

18. List of Extended Flue Components 22

19. Optional Immersion Heater 23

This appliance must be installed by a competent person in accordance with
the Gas Safety Regulations and these instructions. Installers must be CORGI
Registered. Failure to install appliances correctly could lead to prosecution.

This appliance must be installed in accordance with the relevant requirements
of the current Gas Safety (Installation and Use) Regulations 1998, Local
Building Regulations, Building Standards (Scotland) Regulations, Current IEE
Wiring Regulations Health and Safety Document No. 635 “The Electricity at
Work Regulations 1989” and the Byelaws of the Local Water Undertaking.

The installation must also comply with the relevant recommendations of the
following British Standards:

Baxi supports the Benchmark initiative and the aims of the programme.
Benchmark has been introduced to improve the standards of installation and
commissioning of central heating systems in the UK and to encourage the
regular servicing of all central heating systems to ensure safety and efficiency.

1. SAFETY REGULATIONS

POWERMAX –

HIGH PERFORMANCE HOT WATER AND HEATING

Installation and Servicing Instructions

Powermax 140 and 155x are combination boilers
in which the gas burner heats the contents of a
built-in thermal store. This heated water is used
as ‘primary’ water and circulated, as required, to
the radiators. Domestic hot water (‘secondary’
water) is heated by a heat exchanger and
delivered via a thermostatic blending valve which
prevents the hot water exceeding 60°C. The flow
rate is governed to a maximum of 12 litres per
minute (140) and 18 litres per min (155

x.

A fully pre-mixed burner is used to ensure that
the gas is burned cleanly and efficiently. Ignition
is fully automatic and the ignition controller
incorporates a flame safety device.

A small diameter twin pipe flue system has been
designed for a length of up to 9.0 metres
(including a balanced flue terminal) through which
to draw inlet air and expel exhaust gases.
The standard terminal suits a wall thickness of
200mm to 500mm.

The appliance thermostat maintains the thermal
store at about 80°C and this stored water is
circulated through radiators via a pump inside the
casing.
A cold start thermostat prevents the pump from
operating until working temperature (approx.
60°C) is attained.

For summer operation the central heating can be
switched off by the user.

CP models come fitted with both CH pump and
an electronic 7-day, 3-event programmer.
Provision is made for fitting both room and frost
thermostats if required.

Installation of Sealed System models only may
fall within the scope of the Building Regulations
1992 (Part G). These require that installation of
an ‘unvented’ system shall only be carried out by
a competent person as defined in the Approved
Document G3. The above requirements do not
apply to a Powermax installed as part of an open
vented system.

Take particular care to avoid damaging outer
panels, switches, programmer etc. Trucking must
be done from the rear.

Store the appliance under cover in dry conditions.

Handling and Storage

Operation

2. DESCRIPTION

BS6891:1988

Specification for low pressure gas
pipework in domestic premises

BS5440:Part 1:1999
Specification for installation of flues

BS5440:Part 2:2000
Specification for installation of
ventilation for gas appliances (except
that compartment ventilation is
amended as in section 7 of these
Instructions).

BS5546:1990
Specification for installation of gas hot
water supplies

BS5449:1990
Specification for forced circulation hot
water central heating systems

BS6798:1987
Specification for installation of gas
fired hot water boilers of rated input
not exceeding 60kW

3

These boilers require a natural gas supply of 1.6 to 2.0 cubic
metres per hour. Gas supply pipework of not less than 22mm
diameter should be run to the appliance and to within 300mm of
the gas valve (gascock) and should be installed in

accordance with BS6891:1988. (i.e. The pressure drop

between meter and appliance not to exceed 1mbar).

The gas connection to the appliance is Rp

1

/2 (1/2 in B.S.P.) Entry

holes are provided through the controls chassis.
The complete installation must be tested for soundness and

purged as described in the above standard and in accordance
with Corgi recommendations.

The appliance requires a 230V ~ 50Hz single phase 3A fused
electrical supply which must be installed in accordance with the
current IEE Wiring Regulations and any Local Regulations
which apply. Detailed wiring instructions are given in Section 10.
Power consumption is approximately 140W for the appliance,
with the Central heating pump rated at an additional 40W to
88W depending upon pump speed.

WARNING : THIS APPLIANCE MUST BE EARTHED

Note: This appliance may be installed in any room or internal
space, although particular attention is drawn to the
requirements of the current IEE Wiring Regulations, and in
Scotland, the electrical provisions of the Building Regulations
with respect to the installation of the appliance in a room or
internal space containing a bath or shower. Where a room­sealed appliance is installed in a room containing a bath or
shower, any electrical switch or appliance control, utilising
mains electricity should be so situated that it cannot be touched
by a person using the bath or shower.

4. ELECTRIC SUPPLY

3. NATURAL GAS SUPPLY

The appliance must be installed on a flat floor capable of
supporting the weight of the unit when full of water – up to
185kg. It should be sited to minimise the length of flue and to
avoid long hot water pipe runs.
The extended flueing capability enables the appliance to be
sited well away from an outside wall, thus installation in a first
floor cupboard or compartment, basement, utility room or
kitchen are all feasible locations. The appliance must not be
sited outside or in any outhouse where it could be exposed to
the weather.
The location chosen must permit the provision of a satisfactory
external flue termination. The location must also provide
adequate space for servicing and air circulation.
If floor settlement is likely due to the weight of the appliance,
ensure that pipework design is able to accommodate this.

When using an extended flue system it is essential to fit
protective ducting (such as that supplied in the extended flue
kits) in order to prevent direct contact with the hot flue pipe.

General requirements for cupboard/compartment installations,
including airing cupboards, are given in BS6798. Specific
requirements for Powermax installations are given below.
a The compartment must be ventilated at high and low

level in accordance with BS5440:Part 2 and Section 7
of these instructions.

b The compartment shall be a fixed rigid structure large

enough to allow it and the boiler to be inspected and
serviced. A minimum width between the door jambs of
550mm (21in) must be provided.

c Internal surfaces should be non-combustible or lined

with non-combustible material. Examples of non­combustible materials having a fire resistance of not
less than 0.5 hour are plaster skimmed plasterboard,
and fireproof boarding. The floor need not be lined.
Doors or shelves made from combustible material, e.g.
wood must be at least 75mm from the front or top of
the boiler.

d The door of an understairs cupboard shall have a

BS476:Part 8 fire resistance of not less than 0.5 hour;
and air vents must be direct to outside air.

e The flue pipe must be protected by the ducting supplied

by Baxi UK or by another no less suitable non­combustible enclosure.

f Householders should be discouraged from storing

clothes etc on the boiler itself. A removable shelf at
least 75mm above the boiler is acceptable.

Detailed recommendations for flueing are given in
BS5440:Part 1. The following notes are intended to give general
guidance. The appliance must be installed so that the flue
terminal is exposed to the external air, preferably on a clear
expanse of wall. Acceptable positions are indicated in Fig.5.1.

Avoid positions where the terminal is adjacent to projections;
particularly immediately under a balcony, inside a re-entrant
position, or immediately adjacent to a drain pipe.

If the appliance is fitted under a ventilator or opening window,
the terminal must be at least 300mm (12in) from any part of the
window or ventilator, and in accordance with BS5440:Part 1.

Requirements for horizontal
balanced flue terminations

Compartment Installation

Flue Protection

General

5. SITING THE APPLIANCE

Powermax
Sealed System
Schematic

AIR VENT

PRESSURE

RELIEF

CH FLOW

CH RETURN

GAS

CH

FLOW

CH

RETURN

FLUECOMBUSTION AIR

BLENDING VALVE DHW

COLD MAIN

4

Where the lowest part of the terminal is less than 2m (6ft) above
the level of any ground, balcony, flat roof or place to which
people have access, the terminal must be protected by a guard
of durable material. A Terminal Guard Kit is available as an
optional extra Part No. P210 from Baxi UK. The guard requires
a flat wall surface of approximately 450mm diameter,concentric
with the terminal assembly.

The exhaust flue pipe of the terminal must not be closer than
25mm(1in) to combustible material. Additional clearance must
be provided when passing the flue through timber walls.

Advice on gas installations in timber framed buildings is
contained in an IGE technical publication available from the
Institution of Gas Engineers, 21 Portland Place, London W1N 2AF.

Several flueing systems are available. ALL are ‘room sealed’
and a choice of terminals is offered:

1. Horizontal balanced flue terminal.

2. Vertical balanced flue terminal.

3. Ridge tile terminal (unbalanced)

4. Mini terminal balanced flue systems

All terminals can be sited up to 7.0m from the boiler. In some
circumstances, a horizontal terminal can be sited 9.0m from the
boiler – See below. Flue systems are supplied in kits, or
components can be ordered individually-see list in section 17.

Before starting an installation, check that the correct flue
kit has been supplied with the boiler.

The efficient operation of Powermax will naturally give rise to
condensation in the flue gases and pluming will be visible
during adverse atmospheric conditions. In installations with long
flue runs some condensate may be discharged from the
terminal. The terminal must, therefore, be sited to avoid
nuisance from either phenomenon.

Visible Pluming

6. FLUEING OPTIONS

Use Kit P260 for installations where the flue passes through the
wall immediately behind the appliance. The terminal is suitable
for a thickness of 200mm to 500mm as shown in Fig.6.1.
An 800mm wall liner P337 can be ordered separately.
Step-by-step instructions are given in Section 9.

Kits are supplied as follows with components also available
separately.

Kit No.

The maximum length of each air/flue pipe must not exceed 5m
(including a Horizontal BF Terminal) when the maximum of 4 air
pipe bends and 3 flue pipe bends is used – see Fig 6.3.

The pipes can leave the boiler horizontally to right or left, or
rearwards, or vertically upwards.

There is no minimum length.
If fewer bends are used between the appliance and the flue

terminal, the maximum length of straight pipe can be increased
if required – see table below.

Kit P242 allows the flue to terminate at an approved (gas vent)
Ridge Tile Terminal with combustion air being drawn from a
ventilated loft space or from a second ridge terminal. The inlet
terminal must be not less than 300mm above the top surface of
the ceiling insulation.The air inlet pipework must be at least

1.5m long and not less than half the flue length. Full fixing
instructions are supplied in each kit.

Additional components may be specified up to the maximum
indicated in the diagram and the table opposite.

Combustion air may be drawn from a ventilated roof space or
from a compartment or duct which is permanently ventilated
direct to outside air. The effective open area of the vent must
not be less than 160cm

2

(25in2).

When combustion air is drawn from a roof space or
compartment or duct, that area must be effectively sealed from
the remainder of the dwelling. A tight fitting trap door or similar
is acceptable.

Ridge Tile Terminal

Fig. 6.5

Extended Balanced Flue Systems

Fig. 6.3

Balanced Flue Terminal

1m Sideways horizontal balanced flue P261

3m Extended horizontal balanced flue P263

5m Extended horizontal balanced flue P265

7m Extended horizontal balanced flue P267

9m Extended horizontal balanced flue P269

Refer to Section 17 for step-by-step fixing instructions.

MAX. No OF BENDS MAXIMUM PIPE

(90° OR 135°) LENGTH

Air Inlet Exhaust Flue Total Air/Flue inc. Horizontal Trml.

4 3 7 5.0m each
3 2 5 7.0m each
2 1 3 9.0m each

Lagging is recommended when the flue pipe exceeds 3m. The
insulation used must be non-combustible and suitable for
operating at temperatures up to 200°C. Class ‘O’ foil backed
glass wool or mineral wool insulation wrapped tightly around
the flue pipe will help to reduce pluming. It is not necessary to
insulate the air inlet pipes.

Flue Pipe Insulation

Fig. 6.1

‘T’ WALL THICKNESS =
200mm MIN
500mm MAX

Terminal position Min. distance
A: Directly below an openable window or other opening, e.g. an air brick 300mm
B: Below gutters, soil pipes or drain pipes 75mm
C: Below eaves 200mm
D: Below balconies or car port roof (not illustrated) 200mm
E: From vertical drain pipes and soil pipes 75mm
F: From internal or external corners 300mm
G: Above ground or balcony level 300mm
H: From a surface facing a terminal 600mm
I: From a terminal facing a terminal, or from an opening in a car port into 1200mm

dwelling (not illustrated) 1500mm
J: Vertically from a terminal on the same wall 300mm
K: Horizontally from a terminal on the same wall 300mm
L: Between ridge terminals (if combustion air is drawn from second terminal) 300mm
M: Between vertical terminal and wall 300mm
NB: Terminals located less than 2m above ground level must be protected by a terminal

guard P210

Fig. 5.1

J

IMPORTANT Any flue pipework in a horizontal plane
MUST run downwards AWAY from the boiler by 5mm
per metre. To prevent water accumulation there must
be no sags or dips in the pipework.

6

5

Fig. 6.2
Mini terminal
flue system

Example of rearwards
flueing to achieve
minimum 300mm
distance between
terminals

Maximum permitted flue run
of 9.0m total length (including
one 90° bend and one 170°
offset Bend in the flue pipe).

Fig. 6.3

Typical routeing of
extended balanced flue

Fig. 6.5
Typical routeing of
ridge terminal flue kit

Note that

the length of

the air inlet

pipe must not

be less than

0.5 x length
of flue pipe

1.5 TO 4.0 METRES

1.5 TO 5.0 METRES
[STANDARD KIT]

1.5 TO 7.0 METRES

[EXTENDED]

Vertical RS Flue System

The Powermax Vertical RS flue system offers an unobtrusive
balanced flue terminal as an option for both pitched and flat roofs.

The vertical roof terminal Part No. P230 provides a combined air
intake and combustion gas outlet in a concentric arrangement.
Below the roof the terminal changes into a twin pipe system.
Separate roof flashing units should be ordered (specified) for
pitched or flat roofs. Roof pitches from 15° to 55° are catered for
by selecting one of three pitched roof flashing units.

P231 for pitches 15° to 25° P232 for pitches 25° to 45°
P233 for pitches 35° to 55° P236 for flat roofs

To connect the Powermax to the vertical terminal a kit Part No.
P246 is required. This contains a range of extension air/flue
pipes and bends to enable the terminal to be sited up to 2.5m
from the appliance. The maximum overall length of the

complete flue system must not exceed the limits indicated for
extended balanced flue systems, however the length of the

vertical terminal itself can be disregarded. Complete fixing
instructions are provided in each kit.

The Mini Terminal Flue system provides an alternative
arrangement to the standard (140mm diameter) balanced flue
terminal.
Separate 65mm diameter air inlet and flue terminal assemblies
can be positioned in different locations on the same wall subject
to similar wind conditions. See Fig. 6.2.

They are available in a small range of colours chosen for their
compatibility with typical external building materials.

Code.
A Matt Black

(standard finish)

D Red Brick

B Stone

(also suitable for yellow stock brick)

E Slate

C Light Brick F White
Each terminal requires a hole of 65mm diameter to be core

drilled through the external wall.
Flue kits are available as listed below. Each kit contains all the

components needed for a complete system including full fixing
instructions.

Kit No.

* For sideways flueing

WARNING – The flue pipe becomes very hot when appliance
is working. Householders should be warned not to touch
exposed pipe e.g. beyond protective duct within loft.
The flue pipe should be insulated or ducted if accidental
contact is likely.

Description

MINI TERMINAL FLUE

P231/232/233

P230

P236

P234

Fig.6.6 VERTICAL FLUE COMPONENTS

FLUEING RESTRICTIONS – RIDGE TILE TERMINAL

Number of Bends Pipe Length

Application Components 90° or 135° (metres)

Standard Air Inlet 2 1.5 minimum
Kit Flue 3 1.5 minimum

Extended Air Inlet 2-3 1.5 to 4.0
Inlet & Flue 3 max 1.5 to 7.0
Flue

1m Mini Terminal BF kit* P271

3m Mini Terminal BF kit P273

5m Mini Terminal BF kit P275

7m Mini Terminal BF kit P277

9m Mini Terminal BF kit P279

300

170 OFFSET

BEND P320

90 BENDS
P358

SHORT EXTENSION
P338

MINIMUM EFFECTIVE AREA OF
COMPARTMENT AIR VENTS 140 155

xx

Position of opening Ventilated to Area of each vent

High and Low Level Room 54cm

2

60cm

2

High and Low Level Outside 27cm

2

30cm

2

6

7. VENTILATION REQUIREMENTS

a When the appliance is installed in a room or habitable

internal space, there are no specific ventilation requirements.

b When the appliance is installed in a compartment it is

essential that permanent high and low vents are provided for
the circulation of cooling air. Purpose made vents must have
a non-adjustable free area not less than the minimums
specified in the table below.

8. TECHNICAL DATA

Guidance on where to locate the appliance is given in Sections
5, 6 and 7. In some instances it will be advantageous to
pre-plumb pipework or to pre-fix terminal, air/flue pipes and duct.

1. Move appliance to where it is accessible for flue
preparation. For a guide to removing panels, see back
page. Remove 2 screws at bottom of front cover, pull
forward from bottom, gently ease downwards to free
location studs.

140: The lid is retained by 3 screws, 2 in the front edge under

the timer control panel and a third transit screw in the
back of the lid. The lid can be eased upwards from the
rear and pulled gently forwards and away from the
control panel. The transit screw can be discarded if
access is restricted.

155x: Remove recessed screw at top of switch panel and keep

safe. Lift off upper front cover. The top panel is retained
by 4 studs: gently ease upwards to remove. The plinth
cover is retained with 4 screws and 2 screws retain the
rear section.

2. Carefully set aside the outer covers. Remove small
press-out panel(s) either side of casing for plumbing
connection (and flue/air pipes) as necessary. The hand
hold cut outs in the side panels also provide convenient
plumbing access. The cut out in the base allows
pipework to be brought up from floor level, see Plumbing
Guide on page 23, but the pipes must not obstruct
service access to the sump. See Fig. 11.1.

3. Connect one end of electricity supply cable to the user
terminal in accordance with sections 4 and 10. The cable
must be routed via the anchorage and through the
bushing in LH side panel. See Fig. 9.6.

4. Flueing
If installing boiler with vertical RS balanced flue see
separate instructions supplied with vertical flue kit.
If installing boiler with an extended horizontal balanced
flue go to Section 17 of these instructions.
If installing boiler with a Ridge Tile Terminal or Mini
Terminals, see separate instructions supplied with each kit.
The standard flue kit P260 contains the following
components, See Fig.9.2
1 x flue terminal assembly. complete with sealing ring
1 x wall liner
1 x flexible duct AIR INLET ONLY
2 x worm drive clips
Note: The flue terminal assembly MUST be installed
horizontally.
The unit is floor standing and a vertical flat area of wall is
required 1100mm or 1260mm high x 550mm wide. If unit
is being raised above floor level, allow for this in marking
position of flue liner.

4a Mark off the centre of the 140mm (5

1

/2 in) diameter hole
as shown in Fig.9.3 and core drill.
If the wall is clad with a combustible material a 25mm
(1in) wide area around the flue liner must be removed.
Measure the wall thickness and cut the liner to this
length.Cut opposite end to lugs.

b Fit the liner through the 140mm (5

1

/2in) diameter hole
(lugs inside) and cement into position, making good
internal and external rendering. The latter may be done
with arm extended through the liner.

c Insert 50mm diameter 90° elbow into flue socket

(vertically rising pipe at the back of the appliance)

9. INSTALLING THE APPLIANCE

140 155x

Nominal Output, kW gross 14.0 16.4
Nominal Input, kW gross 17.1 20.0
Category I2H Gas G 20
Supply Pressure, mbar 20
Gas Rate m

3

/hr 1.6 2.0
Gas Connection Rc 1/2
Air sense/burner pressure

differential -

–

0.13 ± 0.03mbar.

This is factory set and no

adjustment is intended
NOx < 40 ppm – Class 5
CO < 20 ppm

Thermal store capacity 80 100
(primary water) litres

DHW Temperature °C 55-60 maximum
DHW Flow Rate, litres per 12 18

minute (maximum)
Working Pressures, bar:

Primary SS models 3 max (Design pressure

2.5 to comply with UK
Water Regulations)

Primary OV models 1.0 maximum
DHW 6.0 maximum
DHW 1.5 minimum

Pressure Relief Valve, bar: 3.0
Weight (empty) kg 75 85

Weight (full) kg 155 185
Connections:

CH Flow/Return 22mm Compression
DHW Inlet/Outlet 22mm Compression
Gas Rc 1/2
Pressure Relief 15mm Tube

(1/2 x 3/4 Tundish

supplied loose)

Electricity Supply: 230V ~ 3A fused supply

Cable Entry Top rear of LH panel

Dimensions, mm

Height 1100 1260
Width 540
Depth 600

Clearance requirements for
installation and servicing:

Top 400mm (16 inches)
Sides 5mm (10mm (3/8") total)
Base and back Nil
Front 450mm (18 in) unless

behind an openable door

Flueing:

Flue Types C13 C33 C53

(As flue kit specified)
Bal. Flue Terminal 140mm Diameter
Mini Flue 65mm Diameter
Flue/Air Pipes 51mm Diameter
Standard Flue Length 500mm
Extended Flues Refer to Section 6

(including packaging)

Fig. 9.3 View on front of boiler

* Normal dimensions - check actual height on appliance.

Allow also for floor unevenness.

7

Fig. 9.1

Fig. 9.2

Flue terminal assembly

Flue liner

Inlet duct

Worm drive clip

Fig. 9.4

Fig. 9.5 Flue terminal assembly

Fig. 9.6 Route for incoming electric cables

Refer to page 23 for detailed wiring instructions.

Optional immersion heater

Refer to Guide diagram on page 23. This can be ordered as a
full-size template Part No P3281.

First Fix Plumbing

AIR INLET

140 TOP

RETAINING

SCREWS

(ACCESSIBLE

AFTER

REMOVING

FRONT)

155x PANEL

RETAINING

SCREW

d Measure and cut flue pipes with a hacksaw to a length

as illustrated in fig 9.5. Measure the wall thickness and
add 10mm to the flue pipe and 120mm to the air inlet
pipe from datums ‘AA’. Remove any burrs from cut ends
of tubes.
Note: If wall is not truly vertical or appliance is
prevented from standing against wall, add stand off

distance to wall thickness measurement.

e

Push fully home ensuring inlet air pipe enters flexible
duct and exhaust flue pipe engages socket. Secure inlet
pipe with worm drive clip (See Fig.9.4).

f Carefully push appliance into position, entering terminal

into wall liner. If necessary, fit terminal guard.

5. Make gas connection as described in Section 3.

6. Fix feed and expansion cistern or expansion vessel and
make water connections as described in Section 11.

7. Test gas pipework for gas soundness in accordance with
BS6891 and latest CORGI codes of practice.

TRANSIT SCREW

WALL LINER

FLUE ELBOW

WORM
DRIVE
CLIPS

Std. Balanced Fue

540

135

135

WALL THICKNESS+120mm*

INLET

EXHAUST

WALL THICKNESS+10mm*

*(+ ANY STAND-OFF DISTANCE
BETWEEN APPLIANCE AND WALL)

'A' 'A'

83

)

N

1100(140) 1260(155

)

63

N

948(140) 1123(155

)

N

948(140) 1135(155

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