Chaffoteaux & Maury MINIMA MX2 24 FF NG User guide

c
MINIMA MX2
COMBINATION BOILER
Heating and Instantaneous Domestic Hot Water
Fanned Flue system
Installation, Operating and Servicing Instructions
Manufactures N° Model Type Gas Council N°
200906827037.31 MX2 24 FF NG 47 - 980 - 28
200906828037.31 MX2 30 FF NG 47 - 980 - 29
GB IE

2
These instructions are suitable for the Minima MX2 boilers :
Do not forget the Log Book!
Chaffoteaux & Maury supports Benchmark, the heating industry code to ensure the correct installation, commissioning and
servicing of domestic central heating systems.
To The Householder
Make sure you have a completed Log Book for your boiler. This provides a record of the commissioning of your boiler.
It contains important information about your particular installation that may be required by service engineers. The Log Book will
also provide contact details for the installer should you need guidance in the use of this appliance or if there are any problems.
As with your car, your boiler will work more reliably and efficiently if regularly serviced. We recommend an annual service
check. The service history of the appliance will be recorded on the Log Book.
In the unlikely event of any problems with your boiler or system you should first contact your installer. If your installer cannot
resolve the problem he should telephone our national service helpline.
A charge may be made if Chaffoteaux & Maury Service is called out to resolve a non-product related fault.
Your statutory rights are not affected.
CUSTOMER CARE
Chaffoteaux & Maury, as a leading manufacturer of domestic and commercial water heating appliances is committed to
providing high quality products and a high quality after sales service. If it is necessary to contact an engineer, then telephone
the national warranty helpline 01494 539579.
Advice on installation or servicing can also be obtained by contacting the Chaffoteaux Customer Services Department at High
Wycombe.
CUSTOMER SERVICES DEPARTMENT
Tel: [phone]
Fax: [phone]
GUARANTEE
The manufacturer’s guarantee is for 12 months from the date of purchase. The guarantee is invalidated if the appliance is not
installed in accordance with the recommendations made herein or in a manner not approved by the manufacturer. To assist us
in providing you with an efficient after sales service, please return the guarantee registration card enclosed with the boiler
without delay.
CAUTION
In the United Kingdom, installation, start-up, adjustments and maintenance, must be performed by a competent person only, in
accordance with the current Gas Safety (Installation & Use) Regulations and the instructions provided.
In the Republic of Ireland, the installation and initial start up of the appliance must be carried out by a Competent Person in
accordance with the current edition of I.S.813 “Domestic Gas Installations”, the current Buidling Regulations, reference should
also be made to the current ETCI rules for electrical installation.
All CORGI registered installers carry a CORGI ID card, and have a registration number. Both should be recorded in
your boiler Log Book. You can check your installer is CORGI registered by calling CORGI direct on:- [phone].
Improper installation may cause damage or injury to individuals, animals and personal property for which the manufacturer will
not be held liable. To ensure efficient and safe operation it is recommended that the boiler is serviced annually by a competent
person.
If it is known that a fault exists on the appliance, it must not be used until the fault has been corrected by a competent person.
To The Installer
As part of the commissioning of this appliance it is vital that the Log Book is completed and given to the Householder. Please
ensure that your customer is aware of the importance of keeping the Log Book safe as a record of the installation and the
appliance service history.
Please ensure that your customer is aware of the correct operation of the system, boiler and controls.
This instruction booklet is especially designed for appliances installed in the UK and the Republic of Ireland

3
Table of Contents
PAGE
CUSTOMER CARE
Guarantee 2
Statutory Requirements 2
Table of Contents 3
USER’S INSTRUCTIONS
1 CONTROL PANEL 5
2 HOW TO USE 6
3 MAINTENANCE 7
4 FLUE GAS SAFETY 7
5 GUARANTEE 7
6 PRACTICAL INFORMATION 7
7 INSTRUCTIONS FOR SETTING THE BUILT IN CLOCK 8
INSTALLER’S INSTRUCTION 9
8 DESCRIPTION 9
9 DIMENSIONS 10
10 HYDRAULIC DATA 10
11 INSTALLATION REQUIREMENTS 11
Reference Standards 11
Codes of Practice 11
Flue 11
Gas Supply 11
Electrical Supply 12
Showers 12
Flushing and Water Treatment 12
System Controls 12
Location 12
12 CONNECTING THE FLUE 13
12.1 Fitting the coaxial flue (Ø60/100 Horizontal) 13
12.2 Fitting the coaxial telescopic flue (Ø60/100 Horizontal) 14
12.3 Fitting the coaxial flue (Ø60/100 Vertical) 15
12.4 Fitting the 5” flue (Ø80/125) 17
12.5 Fitting the twin pipe (Ø80/80) 18
13 INSTALLING THE BOILER 22
14 ELECTRICAL CONNECTIONS 23
15 OPERATING 25
Pressurising 25
Settings 25
Burner gas output setting 26
16 FITTING THE CASING 27
17 COMPLETION 28
18 OPERATIONAL CHECKS 28
19 INSTRUCTING THE END USER 28
20 SETTING THE GAS PRESSURES / GAS TYPE CONVERSION 29
21 PARTICULAR CHARACTERISTICS 30

4
SERVICING INSTRUCTIONS
22 Replacement of Parts 31
22.1 To Gain General Access 31
22.1.1 Removing the front panel 31
22.1.2 Removing the side panels 31
22.1.3 Removing the control panel door 31
22.2 Access to the Combustion Chamber 32
22.2.1 Remove the combustion chamber front panel 32
22.2.2 Removing the burner manifold 32
22.2.3 Removing the electrodes 33
22.2.4 Removing the burner 33
22.2.5 Removing the main heat exchanger 34
22.2.6 Removing the air pressure switch 35
22.2.7 Removing the fan 35
22.3 Servicing and Removal of the Gas Valve 36
22.3.1 Removing the spark generator 36
22.3.2 Removing the gas valve 36
22.4 Access to the Water Circuit 37
22.4.1 Drain down 37
22.4.2 Removing the 3 way valve 37
22.4.3 Removing the float of the flow switch 37
22.4.4 Removing the pressure relief valve 38
22.4.5 Removing the secondary heat exchanger 38
22.4.6 Removing the pump 38
22.4.7 Removing the expansion vessel 39
22.4.8 Removing the overheat thermostat 39
22.4.9 Removing the heating temperature sensor (ntc) 39
22.5 Access to the Control System 40
22.5.1 Removing the P.C.B’s 40
22.5.2 Removing the fuses 40
23 INCORRECT OPERATION 41
24 FAULT FINDING 42
25 ELECTRICAL DIAGRAMS 45
26 SHORT SPARES LIST 46
27 TECHNICAL DATA 48

5
USER’S INSTRUCTIONS
Control panel (Fig. 1)
19. - Pressure gauge
20. - On/off push button and power on indicator light
21.- DHW water temperature setting and start button
22.- Central heating temperature setting and start button
23.- Heating temperature indicator and diagnostic indicator
24.- Orange indicator - Burner ON
25.- Reset push button and red indicator lockout light
Connecting bracket Taps shown in Open position
(Fig. 2)
31 : Central heating flow isolating valve
32 : Domestic hot water outlet
33 : Gas service tap
34 : Cold water service tap
35 : Central heating return isolating valve
16 : Central heating pressure relief valve
1Control Panel
Fig. 2
31
32 33 34
35
16
20 21
23
25
22
24
19
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Fig. 1

6
2How to Use
NOTE:
In some circumstances, it is possible that the pipes (and possibly a radiator) heat up slightly after hot water is drawn. To
prevent this, simply close the central heating flow tap 31 (Fig. 2).
Remember to re-open it at the start of the heating season, when you switch the heating back on by rotating button 22 (Fig. 1)
or by turning the clock on.
Starting up (Fig. 2)
1. Ensure that the mains gas supply isolating tap is open and that the appliance is supplied with power.
2. Ensure that there is sufficient pressure in the heating circuit: the pressure gauge needle should be at a minimum of 1.2 bar
and a maximum of 1.7 bar when cold.
3. Ensure that the appliances gas inlet tap is open 33 (Fig. 2).
Your appliance is now ready to operate.
IMPORTANT!!
When the appliance is operated after a prolonged period of inactivity, the presence of air in the gas supply may hinder the first
attempts at igniting the gas, to correct this see Section 23 “Incorrect Operation”.
To obtain hot water and central heating :
To obtain hot water and central heating;
Press the On/Off button 20; it lights up green when power is supplied;
- turn the hot water temperature control knob 21 to allow water heating ignition when water is being drawn. This knob
allows you to adjust the hot water temperature. While hot water is being drawn, LEDs 23 light up two by two, displaying the
temperature of the water within the boiler,
- turn the central heating temperature control knob 22 to allow heating ignition. This button enables you to adjust the
water temperature in the central heating circuit according to seasonal requirements. LEDs 23 will display the
temperature of the water within the boilers primary circuit.
• Turn the control knob 22 :
- to Max in cold weather
- to Min in mild weather (by turning the knob too far, the Central Heating will swtich off)
Furthermore, if your home is fitted with a room thermostat, set it to the desired indoor temperature.
- the orange indicator light 24 lights up each time the burner operates
Stopping the central heating
- turn the central heating control knob 22 to the «off » position (fully anti-clockwise). The boiler then produces only hot water.
Stand-by mode
- turn the control knobs 21 and 22 to the «off »position (fully anti-clockwise), button 20 (Fig. 1) remains lit. The appliance
remains in stand-by mode unless the anti-frost device is activated.
Turn off the appliance*
- press button 20 , the indicator light turns off
- turn off the electricity supply to the water heater.
*NOTE: IN THIS STATE THE APPLIANCES ANTI-FROST DEVICE IS INACTIVE

7
The boiler is fitted with a safety system which authorises operation of the burner. If this device does not detect movement in
the flue the boiler will shut down for safety reasons, and indicators 40, 60 and 80 flash 23 (Fig. 1).
IMPORTANT:this flue gas checking device must not be removed, or have untimely work carried out on it. If it needs to be
replaced, only original parts may be used.
4
Flue Gas Safety
6Practical Information
The manufacturer`s guarantee is for 12 months from the date of purchase. The guarantee is voidable if the appliance is not
installed in accordance with the recommendations made herein or in a manner not approved by the manufacturer. To assist us
in providing you with an efficient after sales service, please return the guarantee registration card enclosed with the boiler with-
out delay.
5Guarantee
Your boiler will work more reliably and efficiently if regularly serviced. We recommend an annual service check. The service
history of the appliance will be marked on the Log Book.
3Maintenance
Pump anti-sticking device
With the boiler switched on (indicator light 20 lit), the circulation pump operates for 1 minute after the appliance has been out
of operation for more than 23 hours, to prevent the pump jamming.
Precautions to take in freezing conditions
We recommend that you contact your installer or After-Sales service, who will advise you of the measures to take according to
your circumstances.
Heating circuit
Take one of the following steps:
- 1) drain the circuit of the heating appliance
- 2) protect the heating appliance with an anti-freeze product.
- 3) allow your appliance to run at low load by setting the room thermostat to a low temperature (between 5 and 10°C).
- 4) leave the power to the boiler on. It is fitted with an anti-freeze device which activates the circulation pump, then the
burner.
- Alternatively the appliances central heating and hot water circuit can be drained. Please consult your installer or local
service agent.

8
3
6
9
12
Fig. 3
7Instruction For Setting the Built-in Clock (If Fitted)
1. General layout
The mechanical clock covers a 24 hour period. Each tappet
represents 15 minutes A(Fig. 4). An override switch is
located on the clock B(Fig 4).
2. To set the time
To set the time of day, grasp the outer edge of the dial and
turn slowly clockwise until the correct time is lined up with
the arrow C(Fig. 4).
3. To Set the "On" and "Off" times
The clock uses a 24hours system. e.g. 8 = 8.00 am and
18 = 6.00 pm "ON" periods are set by sliding all tappets
between the "ON" time and the "OFF" time to the outer edge
of the dial.The tappets remaining at the centre of the dial are
the "OFF" periods.
4. For operation
Put the selector switch Bto the symbol to control the
central heating by the clock. Put the switch Bto «I» to select
permanent operation or to «0» to turn the central heating off
permanently.
Fig. 4
1
1
22
33
44
55
66
77
88
99
1010
1111
1212
1313
1414
1515
1616
1717
1818
1919
2020
2121
2222
2323
2424
99
66
1212
I
A
C
B

9
8Description
INSTALLER’S INSTRUCTIONS
Fig. 5
1
2
14
4
5
6
12
3
10
15
17
16
18
Fig. 6
7
8
9
11
1.- Steel chassis complete with expansion vessel
2.- Sealed chamber
3.- Flue hood with fan
4.- Main heat exchanger
5.- Combustion chamber
6.- Multi-gas burner assembly comprising ignition and
ionisation electrodes
7.- Gas valve assembly
8.- Pump with automatic air separator and automatic vent
9.- Overheat safety cut-out
10 - Return thermistor
11.- Flow thermistor
12.- Electrical box
13.- Hot water flow sensor
14.- Air pressure switch
15.- Ignitor
16.- Central heating pressure relief valve
17.- Three way valve
18.- Secondary heat exchanger
19.-Pressure gauge
20.-On/off push button and power on indicator light
21.- DHW temperature setting and start button
22.- Central heating temperature setting and start button
23.- Heating temperature indicator and fault diagnostic
indicator
24.- Orange indicator - Burner ON
25.- Reset push button and red indicator lock-out light
13
20 21
23
25
22
24
19
Fig.7
c

10
440
450 mini pour entretien
Fig. 8
9Dimensions
54 54 54 54
JKLMN
I
JKLMN
32
296
141
289
15 21
720
652
121,5 I
172,5
18,5
18
All dimensions in mm
With packaging :
24 kW : 32 kg
30 kW : 33 kg
.10 Hydraulic Data
Fig. 9
Fig. 10
The boiler is fitted with an automatic by-pass as standard.
The graph (fig. 9) shows the development of the pressure
available in relation to flow on exit from the boiler. (Designed
temperature rise = 20oC).
To ensure correct operation, the minimum flow of the
appliance must be 300 l/h. (Thermostatic taps closed).
Capacity of the installation.
The water heater is fitted with a pressurised expansion
vessel.
Maximum. volume of expansion vessel: 6 litres.
Pressure: 1 bar.
The volume of the expansion vessel in a pressurised
appliance varies according to:
- the average operating temperature in °C
- the static height, which is the difference in metres between
the highest point of the appliance and the expansion vessel
axis).
The minimum cold filling pressure of the appliance is 1 bar
(recommended pressure between 1.2 and 1.7 bar).
The pressure of the expansion vessel should always be
greater than the static height (in metres) divided by 10.
0
4
3
2
1
5
6
100 200 800 700
600
500
400
300 900 100011001200 l/h
mCE Débit mini (robinets thermostatiques fermés)
Pression disponible
20 40 60 80 100 120
Pf
140 160 180 200 220 240
1,0
1,1
1,2
1,3
1,4
1,5
1,6
1,7
1,8
1,9
2,0
Capacité maximale de l'installation (en litres)
260
Pression à froid pour le circuit chauffage (en bar)
280
40°C
50°C
60°C
70°C
80°C
390
minimum space required 450mm
ISafety valve C/H
J Heating flow
K D.H.W. flow
L Gas supply
M Cold water inlet
N Heating return
C litre
Pump head available at the outlet of the boiler
System capacity chart
Pump head available
Minimum flow rate (with all heating thermostatic valves closed)
Central heating initial pressure when cold (in bar)

Reference Standards
In the United Kingdom, the installation and initial start up of
the boiler must be by a CORGI Registered installer in
accordance with the installation standards curently in effect,
as well as with any and all local health and safety standards
i.e. CORGI.
In the Republic of Ireland the installation and initial start up of
the appliance must be carried out by a Competent Person in
accordance with the current edition of I.S.813 “Domestic Gas
Installations” and the current Building Regulations, reference
should also be made the the current ETCI rules for electrical
installation.
The installation of this appliance must be in accordance with
the relevant requirements of the Local
Building Regulations, the current I.E.E.
Wiring Regulations, the by-laws of the
local water authority, in Scotland, in
accordance with the Building Standards
(Scotland) Regulation and Health and
Safety document No. 635, “Elelectricity at
Work Regulations 1989” and in the
Republic of Ireland with the current edition
of I.S. 813 and the Local Building
Regulations (IE).
C.O.S.H.H.
Materials used in the manufacture of this
appliance are non-hazardous and no
special precautions are required when
servicing.
Codes of Practice
Installation should also comply with the following British
Standards Codes of Practice:
BS 7593:1992 Treatment of water in domestic hot
water central heating systems
BS 5546:1990 Installation of hot water supplies for
domestic purposes
BS 5440-1:2000 Flues
BS 5440-2:2000 Air Supply
BS 5449:1990 Forced ciculation hot water systems
BS 6798:1987 Installation of gas fired hot water
boilers of rated input not exceeding
60kW
BS 6891:1989 Installation of low pressure gas pipe up
to 28mm
BS 7671:2001 IEE Wiring Regulations
BS 4814:1990 Specification for expansion vessels
BS 5482:1994 Installation of L.P.G.
and in the Republic of Ireland in accordance with the following
codes of practice
I.S. 813 Domestic Gas Installations
must be made to British Gas Document DM2, or advice sought
from CORGI.
Avoid installing the boiler where the air inlet can be polluted
by chemical products such as chlorine (swimming pool area),
or ammonia (hair-dresser), or alkalin products (launderette)
Flue
Detailed information on flue assembly can be found in Section
12 “Connecting the Flue”.
The boiler must be installed so that the flue terminal is
exposed to the free passage of external air at all times and
must not be installed in a place likely to cause nouisance. It
must not be allowed to discharge into another room or space
such as an outhouse or closed lean-to.
The terminal should be located with due regard for the
damage or discolouration that might occur to buildings in the
vicinity and consideration msut also be given to adjacent
boundaries.
In cold or humid weather, water vapour may condense on
leaving the flue terminal. The effect of such “pluming” must be
considered.
The minimum acceptable clearances are shown below:
- A Directly below an opening, window, etc 300 mm
- B Above an opening, window, etc 300 mm
- C Horizontally to an opening, window, etc 300 mm
- D Below gutters, soils pipes or drain pipes 75 mm
- E Below eaves 200 mm
- F Below balconies or car port roof 200 mm
- G From a vertical drain pipe or soil pipe 150 mm
- H From an internal or external corner 300 mm
- I Above ground roof or balcony level 300 mm
- J From a surface facing the terminal 600 mm
- K From a terminal facing the terminal 1200 mm
- L From an opening in the car port into the dwelling 1200 mm
- M Vertically from a terminal on the same wall 1500 mm
- N Horizontally from a terminal on the same wall 300 mm
- Q Fixed by Ubbink Rolux 4 GM flue terminal
NOTE: THE FLUE MUST NOT BE INSTALLED IN A PLACE LIKELY TO
CAUSE A NUISANCE.
It may be necessary to protect the terminal with a guard.
Reference should be made to the Building Regulations for
guidance. Suitable guards may be obtained from the following
manufacturer:
Quinnel Barret & Quinnel Wireworks
Old Kent Road
London SE15 1NL
Tel: [phone]
11
11 Installation Requirements
A
B
GH
JC
LMN
K
ID,E
F
Q
H
N
M
Q
Q
I
Fig. 11

12
Ventilation
The room in which the boiler is installed does not require specific
ventilation. If it is installed in a cupboard or compartment
permanent ventilation is not required for cooling purposes.
Gas Supply
The gas installation and soundness testing must be in
accordance with the requirements of BS 6891.The boiler
requires a 22 mm supply. Ensure that the pipe size is
adequate for demand including other gas appliances on the
same supply.
Electrical Supply
The appliance requires an earthed 230V - 50 Hz supply and
must be in accordance with current I.E.E. It must also be
possible to be able to completely isolate the appliance
electrically. Connection should be via a 3 amp fused double-
pole isolating switch with contact separation of at least 3 mm
on both poles. Alternatively, a fused 3 Amp. 3 pin plug and
unswitched socket may be used, provided it is not used in a
room containing a bath or shower. It should only supply the
appliance.
The boiler is suitable for sealed systems only. The maximum
working pressure for the appliance is 10 bar. All fittings and
pipework connected to the appliance should be of the same
standard. If there is a possibility of the incoming mains
pressure exceeding 10 bar, particularly at night, then a
suitable pressure limiting valve must be fitted.
The boiler is designed to provide hot water on demand to
multiple outlets within the property. If there is a requirement
for greater demands, for example if the property has several
bathrooms and cloakrooms, a vented or unvented hot water
storage system may be used.
Showers
Any shower valves used with the appliance should be of a
thermostatic or pressure balanced type. Refer to the shower
manufacturer for performance guidance and suitability.
Flushing and Water Treatment
The performance of the appliance could be impaired by
system debris or the effects of corrosion. The system must
be flushed thoroughly to remove metal filings, solder,
machining oils and other fluxes and greases before
connecting the boiler. If it is an existing system, an
appropriate flushing and descaling agent should be used.
Refer to BS 7593 (1992) for guidance. For more information
on the use of corrosion inhibitors, flushing and descaling
agents, advice can be sought from the manufacturers of
water treatment products such as:
Betz Dearborn Ltd
Foundry Lane
Widnes
Cheshire
WA8 8UD
Tel: [phone]
Fernox Manufacturing
Britannica Works
Clavering
Essex
CB11 4QZ
Tel: [phone]
System Controls
The boiler is electrically controlled and is suitable for most
modern electronic time and temperature controls. The
addition of such external controls can be beneficial to the
efficient operation of the system. The boiler connections for
external controls are 24V and so only controls of 24V or that
have voltage free contacts should be used.
Location
The boiler can be installed on any suitable internal wall.
Provision must be made to allow the correct routing of the flue
and siting of the terminal to allow the safe and efficient
removal of the flue products. A compartment or cupboard may
be used provided that it has been purpose-built or modified for
the purpose. It is not necessary to provide permanent
ventilation for cooling purposes. Detailed recommendations
are given in BS 5440 pt 2. If it is proposed that it is installed in
a timber framed building then reference
Where a room sealed appliance is installed in a room
containing a bath or shower, the appliance and any
electrical switch or appliance control, utilising mains
electricity should be situated specifically in accordance
with current IEE Wiring Regulations.
For unusual locations, special procedures may be necessary.
BS 6798:1987 gives detailed guidance on this aspect.
11 Installation Requirements (continued)

13
12 Connecting the Flue
12.1 Fitting the coaxial flue (Ø 60/100 Horizontal)
The boiler must only be installed with a flue supplied by the boiler manufacturer.
These kits are supplied separately to the appliance in order to respond to different installation solutions. For more information
with regard to the inlet/outlet accessories consult the flue brochure and the following instructions.. The boiler is predisposed for
the connection to a twin flow concentric gas intake and exhaust duct system.
WARNING!!
The exhaust gas ducts should not be in contact with or close to
inflammable material and should not pass through building structures or
walls made of inflammable material.
When replacing an old appliance, the flue must be changed.
IMPORTANT!!
Ensure that the flue is not blocked.
Ensure that the exhaust gas ducts do not
have leaks
Ø 60/100 mm
CONTENTS:
1XSILICONE O-RING (60mm)
1XELBOW (90O)
2XWALL SEALS (INTERNAL &EXTERNAL)
1XALUMINIUM FLUE PIPE INCLUDING TERMINAL (1 METRE - 60/100)
2XFLUE CLAMPS
4XSCREWS
2XSEALS
Once the boiler has been positioned on the wall, insert the elbow into the socket and rotate to the required position. NOTE: It is
possible to rotate the elbow 360oon its vertical axis.
Using the flue clamps, seals and screws supplied (Fig 12) secure the elbow to the boiler.
The 1 metre horizontal flue kit (705958) supplied is suitable for an exact X dimension of 823mm, and the 750mm horizontal
flue kit (705785) is suitable for an exact X dimension of 573mm.
Measure the distance from the face of the external wall to the face of the flue elbow (X - Fig 12), add 22 mm to this
measurement, you now have the total length of flue required (including the terminal), this figure must now be subtracted from
860mm, you now have the total amount to be cut from the plain end of the flue.
Cut the flue to the required length ensuring that the distance between the inner and the outer flue is maintained (Fig 13).
Fig. 12

14
12 Connecting the Flue (continued)
e.g.X = 508mm + 22mm = 530mm
860 - 530 = 330mm (Length to be cut from the plain end of the flue).
Once cut to the required length, ensure that the flue is free from burrs and reassemble the flue. If fitting the flue from inside of
the building attach the grey outer wall seal to the flue terminal and push through the flue through the hole, once the wall seal
has passed through the hole, pull the flue back until the seal is flush with the wall. Alternatively, the flue can be installed from
outside of the building, the grey outer seal being fitted last.
25 mm
25 mm
25 mm
Fig 13
CONTENTS:
1XSILICONE O-RING (60mm)
1XELBOW (90O)
2XWALL SEALS (INTERNAL &EXTERNAL)
1XALUMINIUM FLUE PIPE INCLUDING TERMINAL (TELESCOPIC - 60/100)
2XFLUE CLAMPS
8XSCREWS
2XSEALS
The telscopic flue is suitable for use with an exact minimum X dimension of 270mm and an exact maximum X dimension
470mm.
IMPORTANT!!
Do not extend the telescopic flue to an X dimension of more than 470mm. If longer lengths are required use
extension pieces as necessary. Under no circumstances must the flue be cut.
The wall must then be made good around the flue (ensuring a fall of 1ois maintained away from the boiler to the flue terminal).
Once made good, place the inner (white) wall seal over the flue and push up to the wall, secure the flue to the elbow by using
the clamp supplied.
For each additional 90oelbow 1 metre must be removed from the total flue length (maximum 4 metres including the 1st elbow).
For each additional 45oelbow 0.5 metre must be subtracted from the total flue length (Fig 16).
12.2 Fitting the telescopic flue (Ø 60/100 Horizontal)
WARNING!!
Consult the table on Page 19, to see if a restrictor is
required for the type of flue system being used. Should it
be necessary to fit the restrictor, it must be fitted as shown
in Fig. 14.
Coaxial Fig 14

15
12 Connecting the Flue (continued)
CONTENTS:
1XSILICONE O-RING (60mm)
1XCONICAL ADAPTOR (60/100mm)
1XVERTICAL FLUE KIT (80/125mm)
3XSCREWS
The vertical flue kit is supplied with a specially designed weather proof terminal fitted, it can be used either with a flat roof or a
pitched roof. (see Figs. 17 and 18).
The Vertical flue kits maximum and minimum useable lengths with both flat and pitched roof flashings are indicated in Figs. 17
and 18 also).
12.3 Fitting the coaxial flue (Ø 60/100 Vertical)
Before proceeding to fit the flue, ensure that the maximum flue length has not been exceeded and that all elbows and bends
have been taken into consideration, the maximum flue length is 4 metres, for each additional 90oelbow 1 metre must be
subtracted from the total flue length, and for each 45o0.5 metres must be subtracted from the total flue length (the offset and
height of 2 x 45obends can be seen in Fig. 19).
Mark the position of the flue hole in the ceiling and/or roof (see Fig. 17 for distance from wall to the centre of the flue).
Cut a 120mm diameter hole through the ceiling and/or roof and fit the flashing plate to the roof.
Should it be necessary to cut the flue DO NOT cut the outer white ar inlet tube, cut the aluminium exhaust flue 6mm longer
than the outer white air tube when used at minimum length. DO NOT cut more that 250mm from the inner aluminium exhaust
flue.
To connect the vertical flue kit directly to the boiler, place the adaptor (see Fig. 15) (supplied with vertical flue kit) onto the
exhaust manifold and secure with the clamp, the vertical flue kit must then be inserted through the roof flashing, this will
ensure that the correct clearance above the roof is provided as the terminal is a fixed height.
Should extensions be required, they are available in 1 metre (Part No. 705786), 500mm (Part No. 705790) and 160mm
lengths (Part No. 705812), they must be connected directly to the boiler and secured with the clamp supplied before
connecting the adaptor to allow the vertical flue kit to be fitted. In the event that extension pieces need to be shortened, they
NOTE:MAX LENGTH = a+a+a +
b+b = a+a+a+0.5+0.5
COMBINED LENGTH NOT
TO EXCEED 3m
Fig 15
Fig 16

16
12 Connecting the Flue (continued)
must only be cut at the male end and it must be ensured that the distance between the inner and outer flue are kept (Fig. 13).
When utilising the vertical flue system, action must be taken to ensure that the flue is supported adequately to prevent the
weight being transferred to the appliance flue connection.
When the flue passes through a ceiling or wooden floor, there must be an air gap of 25mm between any part of the flue system
and any combustible material. The use of a ceiling plate will facilitate this. Also when the flue passes from one room to
another a fire stop must be fitted to prevent the passage of smoke or fire, irrespective of the structural material through which
the flue passes.
Fig. 18
Fig. 17
Fig. 19
Minimum offset distance when using 2x 45obends

17
12 Connecting the Flue (continued)
12.4 Fitting the 5” flue (Ø 80 / 125)
Once the boiler has been positioned on the wall, it is necessary to insert the Ø80/125 adaptor into the boiler flue socket.
Place the Ø 60mm insert (Fig. 20) into the boilers exhaust connection;
Fit the grey seal over the boilers flue connection and ensuring all lip seals are fitted correctly push the adaptor onto the boilers
flue connection, checking that the seal is fitted correctly over the adaptor;
To secure the adaptor, use the clamp and screws provided (Fig. 20).
To fit extensions or elbows it is first necessary to ensure that the red lip seal is fitted correctly into the inner flue, once verified,
it is simply necessary to push them together, no clamps are necessary to secure the flue components.
NOTE:WHERE THE TOTAL LENGTH OF FLUE IS GREATER THAN 5 METRES, THE CONDENSATE DRAIN ON THE ADAPTOR MUST BE UTILISED.
Fig. 20
Fig. 21
Minimum offset distance when using 2x 45obends
(Ø80/125 Flue)

18
12.5 Fitting the twin pipe (Ø80/80)
Where it is not possible to terminate the flue within the distance permitted for coaxial flues, the twin flue pipe can be used by
fitting a special adaptor to the flue connector and using the aperture for the air intake located on top of the combustion
chamber.
Considerations necessary for twin flue installation;
It is most important to avoid any possible condense formation entering the appliance.
Condense may form when the 24kW boiler has an exhaust pipe longer than 5.5m and on the 30kW when the exhaust pipe is
longer than 7.5m. If this is the case, there are two options;
1)Where condense will form but can be negated with insulated flue, install the insulated flue ensuring it has a fall of 5mm in
every metre away from the boiler.
2)The exhaust flue will have a fall of 3oback to the boiler and a suitable trap will be fitted on the exhaust as close to the boiler
as possible, condense will then be suitably disposed of.
Where the flue runs through cold spots, i.e. loft areas, condense is likely to be formed, therefore in such cases a fall back to
the boiler and a trap is required.
Always ensure that the flue is adequately supported, avoiding low points. (MTS supply suitable clamps as Part No. 705778).
To utilise the air intake it is necessary to:
1) Take the air intake cover off
2) Assemble the flange on the header supplied with the boiler
3) Insert the restrictor if necessary, on the tube or the elbow
4) Insert the header on the tube or the elbow up until the lower stop
(you do not have to use the washer).
5) Insert the elbow/header in the boiler air intake hole and fasten it with screws
The twin flue pipes can be fitted with or without additional elbows and need no clamps, simply ensure that the red o-ring is
inserted in the female end of the flue pipe and push the extension piece fully into the previous section of flue pipe or elbow,
check that the o-ring is not dislodged when assembling the flue.
Twin pipe can also be converted back to Coaxial flue to enable vertical termination with a coaxial kit by using the pipe bridge
(Twin - Coaxial Adaptor - Part No. 705767). When running the twin flue pipe vertically, a condense trap must always be used
on the exhaust pipe.
It is not recommended that the pipe bridge for horizontal termination, however in the unlikely event that this proves to be a
necessity it is extremely important that the entire flue has a fall of 3oback to the boiler, is suitably trapped and where the
12 Connecting the Flue (continued)
If the two elbows are to be
run in the same lateral
direction and if you need to
reduce the required space
above the boiler, the
minimum 230 mm
measurement can be
reduced by carefully cutting
the elbow below the air inlet
by 25 mm
123,5 135
230 MIN *
200
132
123,5
200
107
25
Fig. 22

19
60mm inner flue of the concentric terminal connects to the pipe bridge, this point must be adequately sealed with silicone
sealant to avoid condense leakage at this point.
NOTE:Vertical twin flue installations must have a trap on the exhaust. MTS supply a suitable condense trap Part No. 705774
and recommend that this be used in the event that the flue may not form condense.
When siting the twin flue pipe, the air intake and exhaust terminals must terminate on the same wall, the centres of the
terminals must be a minimum of 280 mm apart and the air intake must not be sited above the exhaust terminal (refer to Fig.
25). The air intake pipe can be run horizontally, however, the terminal and the final 1 metre of flue must be installed with a fall
away from the boiler to avoid rain ingress.
It is also strongly recommended that the air intake pipe run be constructed of insulated pipe to prevent condense forming on
the outside of the tube.
The maximum permissible flue length for twin flue is dependent on the type of run used.
For flue runs with the intake and exhaust pipes under the same atmospheric conditions (TYPE 4) the maximum length is 24
metres (24kW) and 30 metres (30kW), for runs with the terminals under different atmospheric conditions (TYPE 5) the exhaust
terminal must extend 0.5 metres above the ridge of the roof (this is not obligatory if the exhaust and air intake pipes are
located on the same side of the building). For TYPE 5 also, the maximum permissible combined length is 45 metres (24kW)
and 60 metres (30kW).
The maximum length is reached by combining the total lengths of both the air intake and exhaust pipes. Therefore a
maximum length of 45 metres for example, will allow a flue run of 22.5 metres for the air intake and 22.5 metres for the
exhaust pipes, also for each 90oelbow 1.3 metres must be subtracted from the total length and for each 45oelbow 1 metre
must be subtracted from the total flue length.
Some of the acceptable flue configurations are detailed page 21.
For further information relating to flue runs not illustrated, please contact the Technical Department on 01494 539579.
12 Connecting the Flue (continued)
WARNING!!
Consult the table on Page 20, to see if a restrictor is
required for the type of flue system being used.
Should it be necessary to fit the restrictor, it must be
fitted as illustrated in Fig. 23.
Twin flue
ø 100
60 mm
In the event that twin flue pipes are used, and the
boiler has a side clearance of less than 60mm from
the wall, it is necessary to cut a larger diameter
hole for the flue pipe, this should be ø10 cm, this
will then allow for easier assembly of the air intake
elbow and the tube outside the wall (see Fig. 24).
Fig. 23
Fig. 24

20
Concentric outlet Restrictor
60/100 ø 88.5 Without restrictor Max. length
24 kW L min. = 0.3 m L min. = 1 m 4 m
(Type 1, Type 2, Type 3) L max. = 1 m L max. = 4 m /
30 kW L min. = 0.3 m L min. = 1 m 4 m
(Type 1, Type 2, Type 3) L max. = 1 m L max. = 4 m /
L= total length of gas intake and exhaust ducts.
12 Connecting the Flue (continued)
For coaxial systems, the maximum development value L, mentioned in the table above also takes into accout an elbow.
For twin flue isystems the maximum development value L, mentioned in the table includes the exhaust gas/air intake terminal.
Type 5 outlets should respect the following instructions:
1- Keep the same ø 80 mm for the gas intakes and exhaust gas ducts.
2- If you need to insert elbows in the gas intake and exhaust gas ducts, you should consider for each one the equivalent length
to be included in the calculation of developed length.
3- The exhaust gas duct should jut above the roof by at least 0.5 m.
4- The intake and exhaust gas ducts in Type 5 must be installed on the same wall, or where the exhaust is vertical and the air
intake horizontal, the terminals must be on the same side of the building.
Twin flue outlet Restrictor Restrictor Restrictor Without
24 kW ø 41 ø 46 ø 51 restrictor
Type 4 L min. > 0 m L min. > 2.5 m L min. > 12 m L max. > 19 m
80/80 L max. = 2.5 m L max. = 12 m L max. = 19 m L max. = 24 m
Type 5 L min. > 0 m L min. > 10 m L max. > 29 m L max. > 35 m
80/80 L max. = 10 m L max. = 29 m L max. = 35 m L max. = 45 m
Air intake length 1 m.
L= total length of gas intake and exhaust ducts.
If the exhaust gas duct length is longer than 5.5 m, you will need a condensate drain
Twin flue outlet Restrictor Restrictor Without Without
30 kW ø 44 ø 50 restrictor restrictor
Type 4 L min. > 0 m L min. > 3 m L min. > 12 m L max. > 19 m
80/80 L max. = 3 m L max. = 12 m L max. = 30 m L max. = 24 m
Type 5 L min. > 0 m L min. > 11.5 m L max. > 30 m L max. > 35 m
80/80 L max. = 11.5 m L max. = 30 m L max. = 60 m L max. = 45 m
Air intake length 1 m.
L= total length of gas intake and exhaust ducts.
If the exhaust gas duct length is longer than 7.5 m, you will need a condensate drain
NOTE:UNDER SOME CIRCUMSTANCES, CONDENSE MAY FORM AT THE EXHAUST TERMINAL, SPECIAL ATTENTION MUST BE PAID WITH REGARD
TO POSSIBLE CONDENSE DRIPPING FROM THE TERMINAL