Keston RSM 20/FB Installation and Servicing Manual

COMBINATION WALL HUNG

GAS BOILER

MODEL RSM 20/FB

INSTALLATION & SERVICING

INSTRUCTIONS

DATA BADGE UNDER FRONT PANEL ON BURNER COVER

Manufactured by

THERMOMATIC SRL Casalecchio Di Reno Bologna Italy

exclusively for

High Efficiency Domestic & Commercial Boilers

34 West Common Road Hayes Bromley Kent BR2 7BX

Telephone : [phone] Fax : [phone]

e-mail: [e-mail] Web: www.keston.co.uk

Page 2

TECHNICAL DATA

Heal input (fixed) 26.2kW (89.400 Btu/h)
Heal output 23kW (78.500 Btu/h)
Burner pressure
Burner

14mbar(5.6in.w.g.)
Inlet 2Ombar
Worgas Thermomatic
3 injector 2.35 - 2.70 - 2.35 n

Gas control valve Honeywell VK 4105G
Control Box Honeywell VK 4105G
Filling loop

Inter Albion with Alhilil
double check valve

Boiler control thermostat Ranco K36 Y21
Bimetallic Priority thermostat Cewal 91931199
Overheat thermostat Ranco LM7 P5 043
Anticondensing Thermostat Imit TR2
Electrical supply 240V-50HZ
Power consumption 180 W
Internal fuse rating 3A
Weight empty 77 kg (169.7 Ib)
Weight full 92 kg (203.O Ib)
CH max pressure 3 bar (44 psi)
CH min working pressure 0.5 bar (7.4 psi)
DHW max pressure 10 bar (146 psi)
DHW min working pressure 0.6 bar (8.7 psi)
CH expansion vessel 8 litres charged to 0.5 bar (7.4 psi)
DHW expansion vessel

0.1 60 litres charged lo 3.5 L
(51.5 psi)

CH max temperature 90°C
Design temperature rise 11°C
DHW flow at 30'c rise 11.0 l/min
DHW flow at 35'c rise 9.21 l/min

Page 3

43

Contents Figures
Section Page No. Page
Technical Data Inside Internal Design 1.1 5
Front Cover Control Panel 2.1 6
General Description 1 5 Connections 3.1 6
Operating Sequence 2 6 Alternative top tip system 3.1. A 7
Related Documents 3.1 6 Sealed system filling & make-up 3.1. B 8
Gas Supply 3.2 6 Pump Performance 3.2 9
Water Systems 3.3 7 Typical Heating System 3.3 7
Flue Systems 3.4 9 Domestic Hot Water Supply 3.4 9
Appliance Location 3.5 10 Standard Flue Kit Components 3.5 9
Electrical 3.6 11 Optional Horizontal Extension

Flue
Installation Procedures 4 13 Kit Components 3.6 9
Flue System: Cutting & Siting of Terminal 3.7 7
Assembly 4.7 13 Clearances 38 11
Connecting Services 4.8 18 Functional Flow Wiring Diagram 3.9 10
Filling Loop Assembly 4.9 18 Disassembly of panels 3.10 12
Commissioning 5 18 Wiring Diagram 3.11 38
Procedures for part
replacement

Draining 6.3 20
Replacing Fan 6.5 20 Appliance Mounting 4.1 13
Replacing Air Pressure Switch 6.6 21 Flue Positioning 4.2 13
Replacing DHW Expansion
Vessel
Flue Connection 4.4 14
Replacing Automatic Air Vent 6.8 21 Flue Connection 4.5 14
Replacing CM Expansion
Vessel
Replacing Bimetallic Priority Vertical Flue Terminal Locations 4.7 16
Thermostat 6.10 21 Assembled Extended Vertical

Replacing Solenoid of Gas Kit 4.9
Control Valve 6.11 21
Replacing Multifunctional Filling Loop Assembly 4.11 18
Gas Control Valve 6.12 22 Gas Control Valve 5.1 19
Replacing Circulating Pump 6.13 22 Central Heating Expansion

Replacing thermostatic
T/P Gauge 6.14 22 Thermostat Positions 6.4 22
Replacing Safety Valve 6.15 22 Pressure Relief Valve 6.5 22
Replacing Burner 6.16 23 6.7 23
Replacing Injectors 6.17 23 Top view of Boiler 8.1 32
Replacing Flame Sensing
Ignition Electrodes 6.18 23
Replacing Electronic Control
Box 6.19 23
Replacing Green Operating
Light & Red Lockout Button 6.20 23
Replacing On/Off Summer/
Winter Switches 6.21 23
Replacing Filling Loop 6.22 23
Fault Finding Algorithm 7.1-12 24 – 31
Routine Servicing and
Cleaning 8 32
Short Spare Parts List 34 – 36
Complete Boiler Wiring Schematic 37
Wiring Diagram 38 Manual Addendums 40 -

6 20 Time Clock Wiring 3.12 39

Honeywell T6360B Room Slat

Wiring 3.13 39

6.7 21 Flue Positioning 4.3 14

6.9 21 Vertical Flue Clearances 4.6 16

Flue

Vessel

Spare Parts

4.8 & 17

6.2 21

33, 34

Page 4

1 GENERAL DESCRIPTION (Fig.1.1)

The Thermomatic RSM 20/FB is a wall mounted
water jacketed vertical tube Combination Boiler fitted
with a copper coil to give an immediate supply of hot
water.
The appliance is room sealed and fitted with a coaxial
duct for fan powered ventilation, designed for exit to
either side or to the rear of the appliance.
The copper coil containing 2 litres of hot water is
indirectly heated, giving an immediate and continuous
hot water supply.

The central heating pump will not operate until
the boiler temperature reaches 60°C. The pump is

controlled by a capillary thermostat called the anti­condensing thermostat. In addition, a bimetallic
priority thermostat will stop the pump as soon as
domestic hot water is drawn. This allows the full heat
output to be directed to supplying hot water only.
The appliance jacket extends to burner level, so the
walls of the combustion chamber are water-cooled.
This prevents the intense local heating usually
associated with combination boilers and considerably
prolongs the appliance life.
The domestic hot water, being indirectly healed
through a coil of a larger diameter than normally
used, is not so easily affected by calcium impurities
that build up lime scale. This together with the flexing
of the coil due to temperature changes, means
calcium "build-up" is considerably lessened.

With the Summer/Winter switch set to Winter the
appliance will automatically adjust to the central
heating output, which may be a single radiator, ot
any number within the heat ouput of the appliance.
The Thermomalic does not require a 'by-pass' and all
radiators can be fitted with thermostatic radiator
valves.
Unlike many other combination boilers, the Ther­momalic will operate on low water pressures. The
boiler within the casing is cylinder shaped and fitted
with vertical copper flue tubes through which the gas
products pass. These tubes are fitted wiih stainless
steel baffles to increase efficiency and to rapidly
conduct the heat from the gas products to the water
contained within the cylindrical heat exchanger.
An extended copper coil fitted around the vertical
flue tubes is within the water content. The water
content connects to the central healing system and
indirectly heats the domestic water passing through
the coil.
A SIT Controls multifunctional control with electric
ignition is used and temperatures of both central
heating and hot water ate controlled by capillary
thermostats.
The flue extract fan incorporates a pressure control
switch which activates the gas control. In the case of
a fan failure of any kind the gas control fails to safely.

It is recommended that a scale inhibitor should
be fitted in hard water areas.

FIG.1.1 INTERNAL DESIGN

1 Manual air vent cock

2 Gas control valve

3 Stainless steel burners

4 Ignition electrode

5 Pocket for an anticondensing thermostat phial

6 Pocket For safety thermostat phial

7 Pocket for boiler healing thermostat phial

8 Water temperature gauge

9 Automatic air vent

10 Fan motor

11 Expansion vessel

12 Stainless steel Hue baffles

13 Boiler shell

14 Domestic hoi water copper coil

15 Circulating pump

16 Pressure relic! Safely valve

17 Water pressure gauge

18 Bimetallic priority thermostat

19 Air pressure microswitch

20 Air pressure switch body

21 Concentric flue/air pipe

22 Flue terminal

23 Flue hood

24 Electronic control box

25 Room sealed combustion chamber

26 Flame detection probe

27 Mini expansion vessel (Domestic)

Page 5

2 OPERATING SEQUENCE (Fig.2.1}

Red Light Central Heating Switch Temp. Press. Guage

Boiler Control Green Light Fuse On/Off Switch Overheat Switch

2.1 ON-OFF MAIN SWITCH

Allows the appliance to be manually switched on and
off.

2.2 CENTRAL HEATING SWITCH (SUMMER­WINTER)

Allows the central heating and domestic hot water
supply to be switched on. or domestic hot water only
to be switched on.

2.3 BOILER CONTROL THERMOSTAT
Controls the temperature of the water fed to the

central healing system. The temperature can be man­ually adjusted between approximately 50" - 90*C ±
2°C.

2.4 OVERHEAT SWITCH

A boiler overheat switch will operate if the boiler
thermostat exceeds 90*C ± 3%. After determining the
season (of the boiler overheat thermostat operating,
the thermostat can be manually re-set. Note: thermo­stat control cannot be re-set until boiler temperature
falls below 80"C.

2.5 PRESSURE AND TEMPERATURE GAUGE

A combined boiler pressure and temperature gauge
indicates the pressure and temperature of the water in
the boiler. As a guide the pressure of water in the
boiler, with a pressurised system, can be set at 1 bar
when the water is cold.

2.6 BIMETALLIC PRIORITY THERMOSTAT

A bimetallic priority thermostat is fitted al the connec­tion of the domestic cold water inlet to the boiler.
When a hot lap is opened, the bimetallic priority
thermostat is operated by the flow of cold water into
the boiler.

If the central heating switch (summer/winter switch)
is in the Winter position (i.e. central heating ON) the
bimetallic priority thermostat turns off the central
healing circulating pump.

When the domestic hoi water demand is satisfied the
bimetallic priority thermostat allows the pump to
restart.

When only a small domestic hot water flow is drawn
the bimetallic priority thermostat does not intervene.

2.7 ANTICONDENSING THERMOSTAT

This thermostat prevents the central heating emula­ting pump from operating until the boiler water
temperature reaches 60"C

3 GENERAL REQUIREMENTS

3.1

RELATED DOCUMENTS

It is the law that gas appliances be fitted by a
competent person. Failure to do so could lead to
prosecution. It is in your own interest, and that of
safety, to ensure compliance with the law.
Installation shall be in accordance with the following
documents:

- Gas Safety (Installation and Use) Regulation 1984

- Building Regulations

- Building Standards (Scotland) Consolidation

- Current IEE Wiring Regulations

- By-Laws of the Local Water Authority

- BS.6798: Boilers of rated input not exceeding 60KW

- BS5449: Forced circulation hot water systems

- BS.5546: Gas hot water supplies

- BS.5440: Part 1: Flues

- BS.5440: Part 2: Ventilation

- BS.6891: Gas supply

-
Where the appliance is installed in a timber framed

building, reference should be made to the British Gas
Publication reference DM2.

3.2 GAS SUPPLY
See fig.3.1 for connection

Fig. 3.1

A gas meter can only be connected by local gas
legions or by a local gas region contractor. An existing
meter should be checked, preferably by the gas
region, to ensure the meter is adequate to deal with
the rate of gas supply.
Installation of pipes should be in accordance with
BS.6891.
Pipework from the meter to the appliance must be of
adequate size.
Do not use pipes of a smaller size than the appliance
gas inlet connection.

The complete installation must be tested for sound­ness and purged as described in the above code

Page 6

3.3 WATER SYSTEMS

Fig. 3.3 TYPICAL HEATING SYSTEM

3.3.1 Central heating

See Fig.3. f for connections

WARNING: When radiator(s) are at a higher level than the
boiler. A NON-RETURN VALVE MUST BE FITTED lo the
central healing systems flow pipe.

A. Old systems.
These* are likely to contain sludge and debris which, if passed
into the appliance, may cause irreparable damage to the pump
and other components. It is. therefore, highly recommended
that the old system be thoroughly flushed using such as
Fernox cleaner - use in accordance with the manufacturer's
instructions.

B. New systems
Must always be flushed of debris.

C. Design of system
The primary system must be of the sealed type, the designed
temperature rise should be 1 PC.

The following sealed system components are included on the
appliance:

i. Double check valve, stop valve and filling loop,

ii. 8 lilre central heating expansion vessel,

iii. Circulating pump.

iv. CALEFFI relief (safety) valve.

v. D.H.W, Expansion Vessel

vi. Combined temperature and pressure gauge.

D. Expansion vessel/sizing of system
Guidance is provided in BS.7074. Part 1 and BS.5449. The
maximum permissible capacity of the system, including the
appliance, will depend upon the initial design pressure.
As an example, for an initial design pressure of 1 bar the
maximum permitted capacity, including the appliance, is 70
titles.

For calculation purposes:
Existing vessel capacity - 8 litres
(charged at 0.5 bar)
Capacity of appliance - 15 litres
Safely valve setting - 3 Bar

If the system capacity exceeds the allowed value then
an additional vessel must be provided, connected as
close as possible to the appliance heating return.

E. Pressure relief (safety) valve
The valve outlet must be routed to a suitable point of
drainage where there will be no hazard to occupants
and where freezing will not take place.

F. Filling the system
A double check valve, stop valve and filling loop are
supplied. Before using ensure that the arrangement
complies with the requirements of the Local Water
Authority. Alternatively BS 5449:1990 (fig 3.1A) shows
other methods of filling.

Fig. 3.1.A ALTERNATIVE TOP UP SYSTEM

G. System make up
There must be no direct permanent connection to the
mains water supply, hence the filling loop must be
disconnected at one end alter use.
If an automatic top up method is required, then this
must be done via either a cistern which has no other
purpose or a top up bottle. Full details are provided in
BS.5449:! 990 (fig 3.1 B) Again, always check local
Water By-laws before installation. See also Fig.3. l.A.

H. Pump performance
Fig.3.2 shows the pump performance characteristics
and values given take due account of the losses
through the appliance.

I. Thermostatic radiator valves
A by-pass is not required and such valves can be fitted
on all radiators if desired.

J. Drain points
Drain taps should be lilted on the lowest point of the
system, the taps complying with BS.2879

K. Vents
Although an automatic air vent & manual air vent is
provided on the appliance, further facility to vent the
system should be provided.

L. All components and fillings used should be
suitable for temperatures of up to 11O°C and pressures
of up to 3 bar.

All syslem components added must be in occoidance
with US 5-149 and BS.G798.

Page 7

Position 1

1000

30-

35 016

Position It

170O

45-

60 025 Position III

2450

72.92

038

Speed RPM Watts

Input

Full Load
Current in Amps

Fig. 3-2 PUMP PERFORMANCE

M. Central heating pressure
We recommended that the initial design pressure, i.e. when cold, be 1 bar When fully heated and drawing
a full load, the resultant hot pressure must not exceed 2.7 bar. The safety valve will discharge at 3 bar ± 0.3
bar.

N. System design
A typical sealed system is shown in Fig.3.3.

3.3.2 Domestic hot water circuit
See Fig.3.1 for connections
An extended copper coil is filled which is healed from the primary water. Starting from cold, the appliance
should be fully heated before full capacity hot water supply is obtained

IMPORTANT
To conform to the requirements of the National Water Council, il the main water pressure is at any lime in
excess of 73 psi. (5 bars) {1 69(1) a Pressure Limiting or Pressure Reducing Valve must be fined by the
installer into the mains supply in an inconspicuous approved by Ihe NWC and must not allow more than 73
psi. (5 bars) pressure to the appliance.

Page 8

Fig. 3.4 DOMESTIC HOT WATER SUPPLY

3.4 FLUE SYSTEM

3.4.1 The standard balanced flue system can be
directed to the right, left or rear of the appliance.

3.4.2 As supplied, the standard horizontal flue assembly
will cover a distance of up to 910 mm from the centre
line of (he appliance for side flues. for rear flues, a wall
thickness of up to 800mm can be accommodated. Both
dimensions are to the outside wall face.

An optional 1m extension flue system kit (Pan No
R3000050) is available which allows the maximum
lengths to be increased to 1840 mm and 1730 mm
respectively.
An optional 2m extension flue system kit (Pan No
R3000014) is available which allows the maximum
lengths to be increased lo 2840 and 2730 respective­ly

3.4.4 If a vertical flue is required an optional vertical
flue system kit (Part No R3000030) is available
which replaces the standard 1m horizontal Hue
assembly supplied. The vertical flue assembly will
cover a distance of up to 1m from the top of the
boiler flue hood to the end of the air pipe and comes
complete with a terminal rain hood.
Optional extension flue system kits are available to
allow the maximum vertical lengths lo be increased
lo 1975mm (Part No 3OO0050) or 2975mm (Part No

3000014).

Fig. 3.5 STANDARD HORIZONTAL FLUE SYSTEM KIT COMPONENTS

Fig. 3.6 OPTIONAL HORIZONTAL

EXTENSION FLUE
SYSTEM KIT COMPONENTS

Page 9

3.4.5 The flue system must be installed in accordance
with BSS440 Part 1.

3.4.6 Siting of flue terminal
It is essential that products of combustion cannot enter
any building through such as openable windows, doors,
air bricks, etc.
Fig 3.7 gives details of the minimum required spacing of
the 'terminal from building features.

3.4.7 Terminal guard
Where the terminal is fitted within 2m of a walkway. a
balcony or a fiat roof to which people have access, then
a terminal guard, model C.1 must be fitted centrally over
the terminal. This guard is available from KESTON
BOILERS.

3.4.8 Air supply
This appliance is room sealed and. when installed in a
room or space, requires no ventilation. If installed in a
cupboard/compartment, air is required for cooling
purposes, as follows:

Fig. 3.7 SITING OFTHE TERMINAL

Position of Air
Vents

Air from Room
or Internal

Air Direct from
Outside

Space

High level 236 cm²

36-6 ins²

Low level

36.6 ins²

236 cm²

18.3 ins²

1 1 8 cm²

18.3 ins²
1 1 8 cm²

Both air vents must communicate with the same
room or space, or both must be on the same wall to
outside air.

3.5 APPLIANCE LOCATION

3.5.1 This appliance is not suitable for external
installation.

3.5.2 The wall on which the appliance is mounted
must be of suitable load bearing capacity

3.5.3 Installation in a compartment is permitted (full
guidance is provided in BS.6798).

3.5.4 Adequate space must be allowed for installa­tion, subsequent servicing, and safe operation.
Appliance dimensions and the minimum allowable
clearances required are shown in Figs. 3. t and 3.8

TERMINAL POSITION Minimum distance

Fanned draught.

A. Directly below an openable window or other
opening. e.g. an air brick 300 mm
B. Below gutters, soil pipes or drain pipes 75 mm
C. Below eaves 200 mm
D. Below balcony 200 mm
E. From vertical drain pipes and soil pipes 75 mm
F. From internal or external corners 300 mm

TERMINAL POSITION Minimum distance

Fanned draught.

G. Above ground or balcony level 300 mm
H. From a surface facing a terminal 600 mm
I. From a terminal facing a terminal 1200 mm
J. Vertically from a terminal on the

same wall 1500 mm
K. Horizontally from a terminal on the
same wall 300 mm

Page 10

A flexible three-core PVC insulated cable must be
used between the isolator and terminal block with a
minimum cable size of 0.75 mm1 (24 x 0.2 mm)
BS.6500 Table 16
Ensure all cables are secure.

3.6.3 ELECTRICITY SUPPLY

WARNING: THIS APPLIANCE MUST BE EARTHED.

Connection shall be made to a 240 Volts 50 Hz ­supply. K a mains plug connection is used it must be
of a three-pin type and fused to 3 Amps.

To connect a plug

Fig. 3.8 MINIMUM CLEARANCES

3.5.6 The position must allow for correct termination of the
flue system (see Section 3.4).

3.5.6 The combination boiler may be installed in any room
or internal space, although particular attention is drawn to
the requirements of the current I.E.E. Wiring Regulations,
and in Scotland, the electrical provisions of the Building
Regulations applicable in Scotland, with respect to the
installation of the combination boiler in a room or internal
space containing a bath or shower.

Where a room-sealed 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.

3.6 ELECTRICAL

3.6.1 Electrical connections and installation must
conform to current IEE Regulations and. in Scotland, the
electrical provisions of the Building Regulations.

The appliance must be earthed.

Wiring external to the appliance MUST be carried out by a
competent person in accordance with the current IEE
Regulations and Local Regulations which apply. The
Thermornatic Combination Boiler is supplied for
connection to a 240V-50Hz single phase. The appliance is
fused at 3A

3.6.2 The method of connection to the electricity supply
MUST provide means of completely isolating the electricity
supply to the boiler and its ancillary control, preferably by
using a 3A fused three-pin plug and unswitched shuttered
socket outlet both complying with the requirements of 8S.1

363. or alternately a 3A fused double-pole switch having n
3 mm contact separation on both poles.

As the colour of the wires in the mains lead of (he
appliance may not correspond with the coloured
markings identifying the terminals in your plug, proceed
as follows:—
The wire which is coloured green-and-yellow must be
connected to the terminal in the plug which is marked
with the letter E or by the earth symbol or coloured
green or green-and-yellow.
The wire which is coloured blue must be connected to
the terminal which is marked with the tetler:N or
coloured black.
The wire which is coloured brown must be connected to
the terminal which is marked with the letter L or
coloured red.

ELECTRICAL CONNECTIONS

3.6.4 To gain access to the terminal block remove me
four screws fixing (he base panel with the attached front
door and remove the panel (see Fig. 3.10, item 9'1

3.6.5Thread the main supply cable through the cable
restraining clamp, leave enough cable for removal of
control panel to replace any boiler controls.

3.6.6 Ensure earth wire is longer than current carrying
conductors so that if cables are strained or slip in their
anchorage, the current carrying conductors become taut
before the earth wire.

Page 11

Page 12

4. INSTALLATION PROCEDURES

4.1 Unpack the appliance, check the contents:

Combination

i

boiler
Wall plugs

ii

Fixing brackets

iii

Connection

iv

plate with ball
valves

T-bar template

v

Flue assembly with

vi

elbow
Wall liner with flexible

vii

washer
Filling loop with double

vii

check valve

i

4.2 Select the appliance position, taking due account
of Section 3.

4.3 PREPARATION FOR MOUNTING THE
APPLIANCE

The Thermomatic Combination Boiler is supplied with
a connection plate with ball valves and a T-bar
template that allow the installer to make all water and

f Insert the plastic plugs and screw in the fixing brackets
to within 2 of 3 mm ol the wall face.

4.3 Hang the T-bar template on the fixing brackets
and check that it is perfectly horizontal and seated on
the fixing brackets.

4.4.1 Hang the connection plate carrying the valves on
the T-bar template hung on the wall in 4.4 and fix
together using the screws.
Drill four holes in the wall for fixing the connection plate
to the wall, using the existing holes on the connection
plate as a template.
Fix the connection plate to the wall using lour screws in
the holes drilled.

4.4.2 Once the T-bar template and connection plate
have been fixed securely lo the wall make all the gas
and water connections.

4.4.3 Remove the T-bar template and hang the
appliance on the fixing brackets via the two square cut
outs on the top of the appliance.

4.5 Remove the base panel. 4 screws (see fig. 3.10
item 91 Exploded drawing of disassembling the boiler
panels).

4.6Remove the front panel. 2 screws (see fig 3.10 item

93). lift and disengage. Remove the plugs from the cold
water inlet and domestic hot water outlet

4.7 FLUE SYSTEM: CUTTING AND ASSEMBLY

4.7.1 Standard Flue Systems
When fully assembled, the standard flue system will be
shown, side or rear flue (fig. 4.2).

gas connections and test the system before hanging
the boiler. Hence, the boiler itself need only be hung
at the final stage of the works.

a Mark a vertical line for the centre of the appliance
b Mark a horizontal line for the top of the appliance.
c Lay the top edge of the T-bar template onto the
horizontal line and mark two holes on the wall for the
fixing brackets.
d Mark the flue hole centre, either on the rear wall.
ceiling or extended to the required side wall as shown.
e For standard flue systems, drill the flue hole 130mm
diameter, preferably using a core drill.
For extended Flue systems, drill the Flue hole 145
mm diameter

IMPORTANT: The plastic liner must always be used
and the air pipe fixed at the appliance elbow ONLY.

Page 13

Fig. 4.3

a Measure the wall thickness T (fig. 43).
b Maximum available lengths of plastic liner:
Rear flue Maximum wall thickness (standard liner):

580 mm (T)
Maximum wall thickness (optional extension
liner) 828 mm (T).

Side flue Maximum distance from appliance side to

outer wail face: 680 mm (T+ C)
(with maximum wall thickness T as for rear
flues)

When measuring and cutting, always separate the inner
(flue) pipe wiih terminal from the outer (air) pipe.

c Cut the air pipe fig. 3.5 — cut from the plain end.
Rear Flue To overall length (L) oFT + 62 mm.
Side Flue To overall length (L) ofT + C+ 180mm

When cutting the air pipe, take care not to ovalise it and
remove the internal sharp edges produced when cutting
the pipe.
Drill again a hole (4 mm diameter) at a distance of 7mm
from the pipe end F) Fig 3 5 to [he hole center

d Cut the flue pipe — cut from the plain end.
Any Flue Cut off exactly the same amount as removed
from the air pipe.
Drill again a hole (3mm diameter) at a distance of 16
mm from the end of pipe to the centre of hole

e Cut the plastic- liner (S)

f Insert the flue pipe/terminal F) into the elbow A) and
secure with the specific screw.

g Insert the terminal into the plain, i.e. unchannelled
end of the air pipe E).

h IMPORTANT
Before inserting the air pipe into the elbow. LUBRI­CATE THE ELBOW SEAL WITH OIL. then insert the air
pipe completely into the elbow.
If the elbow seal is not lubricated, it is not possible to
insert the air pipe into the elbow.
Take care to let the holes correspond, then insert the
clevis pin (fig 4.4).

i Pass the flue/air pipe assembly through the plastic
liner S).

j Fully insert the elbow A) into the fan socket, ensuring
that the elbow seal is correctly located.

k Check that the terminal protrudes the correct amount
from the wall face (fig. 4.3.).

4.7.2 HORIZONTAL EXTENSION FLUE SYSTEM
a Measure wall thickness T (rig. 4.3)

Page 14