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
c
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.
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.
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 provides a record of the commissioning of your boiler.
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: 01494 539579
Fax: 01494 459775
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:- (01256) 372300.
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.
This instruction booklet is especially designed for appliances installed in the UK and the Republic of Ireland
2
Table of Contents
CUSTOMER CARE
Guarantee 2
Statutory Requirements 2
Table of Contents 3
USER’S INSTRUCTIONS
PAGE
1 CONTROL PANEL
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
5
3
SERVICING INSTRUCTIONS
22
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
Replacement of Parts 31
4
USER’S INSTRUCTIONS
1
Fig. 1
Control panel
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
Control Panel
21
19
(Fig. 1)
20
24
22
23
c
25
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
16
31
Fig. 2
32 33
35
34
5
2
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 “
To obtain hot water and central heating :
To obtain hot water and central heating;
Press the On/Off button
- turn the hot water temperature control knob
allows you to adjust the hot water temperature. While hot water is being drawn, LEDs
temperature of the water within the boiler,
- turn the central heating temperature control knob
water temperature in the central heating circuit according to seasonal requirements. LEDs
temperature of the water within the boilers primary circuit.
• Turn the control knob
Furthermore, if your home is fitted with a room thermostat, set it to the desired indoor temperature.
- the orange indicator light
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.
How to Use
Incorrect Operation”.
20; it lights up green when power is supplied;
21 to allow water heating ignition when water is being drawn. This knob
23 light up two by two, displaying the
22 to allow heating ignition. This button enables you to adjust the
23 will display the
22 :
- to Max in cold weather
- to Min in mild weather (by turning the knob too far, the Central Heating will swtich off)
24 lights up each time the burner operates
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
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
Remember to re-open it at the start of the heating season, when you switch the heating back on by rotating button
or by turning the clock on.
31 (Fig. 2).
6
22 (Fig. 1)
3
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.
Maintenance
4
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.
5
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 without delay.
6
Flue Gas Safety
Guarantee
Practical Information
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.
7
3
6
9
12
7
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
1. General layout
The mechanical clock covers a 24 hour period. Each tappet
represents 15 minutes
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
Instruction For Setting the Built-in Clock (If Fitted)
A (Fig. 4). An override switch is
Fig. 3
Put the selector switch B to the symbol to control the
central heating by the clock. Put the switch B to «I» to select
permanent operation or to «
permanently.
0» to turn the central heating off
A
C
B
Fig. 4
8
INSTALLER’S INSTRUCTIONS
14
11
12
8
1
2
9
Description
1.- Steel chassis complete with expansion vessel
2.- Sealed chamber
3.- Flue hood with fan
3
4.- Main heat exchanger
5.- Combustion chamber
6.- Multi-gas burner assembly comprising ignition and
4
5
10
6
8
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
Fig. 5
18
7
16
15
Fig. 6
24
23.- Heating temperature indicator and fault diagnostic
indicator
24.- Orange indicator - Burner ON
25.- Reset push button and red indicator lock-out light
17
13
23
Fig.7
19
20
21
22
c
25
9
440
450 mini pour entretien
9
54 54 54 54
JKLMN
I
JKLMN
32
296
141
289
15
21
720
652
121,5
I
172,5
18,5
18
0
4
3
2
1
5
6
100
200
800
700
600
500
400
300
900
1000
1100
1200
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
Dimensions
All dimensions in mm
I Safety valve C/H
J
Heating flow
K
D.H.W. flow
L
Gas supply
M
Cold water inlet
N
Heating return
With packaging :
minimum space required 450mm
24 kW : 32 kg
30 kW : 33 kg
390
Fig. 8
.
10
Pump head available
Minimum flow rate (with all heating thermostatic valves closed)
Pump head available at the outlet of the boiler
Central heating initial pressure when cold (in bar)
10
Hydraulic Data
System capacity chart
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 = 20
o
C).
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
Fig. 9
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
C litre
greater than the static height (in metres) divided by 10.
11
A
B
G
H
J
C
L
M
N
K
I
D,E
F
Q
H
N
M
Q
Q
I
Installation Requirements
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).
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
Fig. 11
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
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.
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)
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: 020 7639 1357
11
11
Installation Requirements (continued)
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 doublepole 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:
Fernox Manufacturing
Britannica Works
Clavering
Essex
CB11 4QZ
Tel: 01799 550811
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.
12
Betz Dearborn Ltd
Foundry Lane
Widnes
Cheshire
WA8 8UD
Tel: 0151 424 5351
12
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.
Connecting the Flue
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.
Ø 60/100 mm
Fig. 12
IMPORTANT!!
Ensure that the flue is not blocked.
Ensure that the exhaust gas ducts do not
have leaks
12.1 Fitting the coaxial flue (Ø 60/100 Horizontal)
CONTENTS:
1X SILICONE O-RING (60mm)
X ELBOW (90
1
2X WALL SEALS (INTERNAL &EXTERNAL)
1X ALUMINIUM FLUE PIPE INCLUDING TERMINAL (1 METRE - 60/100)
2X FLUE CLAMPS
4X SCREWS
2X SEALS
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 360
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
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
O
)
o
on its vertical axis.
X dimension of 823mm, and the 750mm horizontal
(Fig 13).
13
12
25 mm
25 mm
25 mm
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.
Connecting the Flue (continued)
Fig 13
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
Fig. 14.
in
Coaxial
Fig 14
12.2 Fitting the telescopic flue (Ø 60/100 Horizontal)
CONTENTS:
1X SILICONE O-RING (60mm)
X ELBOW (90
1
2X WALL SEALS (INTERNAL &EXTERNAL)
1X ALUMINIUM FLUE PIPE INCLUDING TERMINAL (TELESCOPIC - 60/100)
2X FLUE CLAMPS
8X SCREWS
2X SEALS
The telscopic flue is suitable for use with an exact minimum X dimension of 270mm and an exact maximum X dimension
470mm.
O
)
14
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.
o
For each additional 90
For each additional 45
elbow 1 metre must be removed from the total flue length (maximum 4 metres including the 1st elbow).
o
elbow 0.5 metre must be subtracted from the total flue length (Fig 16).
12
Connecting the Flue (continued)
12.3 Fitting the coaxial flue (Ø 60/100 Vertical)
CONTENTS:
1X SILICONE O-RING (60mm)
1X CONICAL ADAPTOR (60/100mm)
1X VERTICAL FLUE KIT (80/125mm)
X SCREWS
3
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).
NOTE:MAX LENGTH = a+a+a +
Fig 15
b+b = a+a+a+0.5+0.5
COMBINED LENGTH NOT
TO EXCEED 3m
Fig 16
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 45
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
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
lengths
connecting the adaptor to allow the vertical flue kit to be fitted. In the event that extension pieces need to be shortened, they
(Part No. 705812), they must be connected directly to the boiler and secured with the clamp supplied before
o
bends can be seen in Fig. 19).
DO NOT cut the outer white ar inlet tube, cut the aluminium exhaust flue 6mm longer
(Part No. 705786), 500mm (Part No. 705790) and 160mm
15
12
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.
Connecting the Flue (continued)
Fig. 17
Fig. 18
Minimum offset distance when using 2x 45obends
16
Fig. 19
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
Minimum offset distance when using 2x 45obends
(Ø80/125 Flue)
Fig. 21
17
12
123,5 135
230 MIN *
200
132
123,5
200
107
25
Connecting the Flue (continued)
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.
o
2)The exhaust flue will have a fall of 3
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.
back to the boiler and a suitable trap will be fitted on the exhaust as close to the boiler
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
Fig. 22
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 3
18
o
back to the boiler, is suitably trapped and where the
12
ø 100
60 mm
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
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.
Connecting the Flue (continued)
must be a minimum of 280 mm apart and the air intake must not be sited above the exhaust terminal (refer to Fig.
For flue runs with the intake and exhaust pipes under the same atmospheric conditions (T
metres (24kW) and 30 metres (30kW), for runs with the terminals under different atmospheric conditions (T
terminal
located on the same side of the building). For T
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 90
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.
must extend 0.5 metres above the ridge of the roof (this is not obligatory if the exhaust and air intake pipes are
YPE 5 also, the maximum permissible combined length is 45 metres (24kW)
o
elbow 1.3 metres must be subtracted from the total length and for each 45oelbow 1 metre
YPE 4) the maximum length is 24
YPE 5) the exhaust
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.
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).
Twin flue
Fig. 23
Fig. 24
19
12
Connecting the Flue (continued)
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.
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
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.
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
20
EXHAUST
AIR INTAKE
AIR INTAKE
AIR INTAKE MUST NOT BE
FITTED ABOVE THE EXHAUST
12
Connecting the Flue (continued)
TYPE 1
TYPE 4
TYPE 2
TYPE 5
NOTE: DRAWINGS ARE INDICATIVE OF FLUEING OPTIONS ONLY.
TYPE 3
Fig. 25
21
13
1
2
- place the template in the selected position on the wall
- fit the hanging bracket
- Install the gas and water pipes and the electrical connection to the locations shown on the fitting template
- Drill the hole for the flue
- unscrew the clamp locking bolt
- remove the front panel from the boiler (1 & 2 Fig. 26)
- offer the water heater up to its bracket and allow it to drop into position while pressing on it (Fig. 27)
- fit the connectors and taps (Fig. 2, page 5)
- connect the water and gas pipes to the boiler, with the various seals
- connect the flue to the boiler (for more detailed instructions on this see
The safety valve discharge pipe must be run to outside and discharge in a place not likely to cause nuisance or injury.
Cleaning the central heating system
Once the central heating system has been connected, it is essential to clean the appliance with an appropriate product (dis-
persing agent), the boiler and system must be filled and flushed cold, the system must be refilled and heated to temperature
and flushed again, to remove filings, solder, and various factory oils and greases. The system must then be refilled again and
inhibited.
Do not use any solvent or aromatic agent.
Installing the Boiler
A, which secures the front panel (Fig. 26)
Section 12 Connecting the Flue).
Fig. 26
A
Fig. 27
37
Fig. 28
22
14
S
T
D
J12
J1
J12
E
J1
Electrical Connections
B
P
IMPORTANT!!
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.
P
Fig. 29
The 240 V and earth connection are made by using the lead provided at J1 (Fig. 30).
I
MPORTANT!!
If the supply cable is damaged, it must be replaced.
Room thermostat connection
Before it leaves the factory, the boiler is set to operate without a room thermostat: a shunt S is placed on connector D.
The room thermostat connection is made on this connector
- Lower the electronic control unit by releasing the side locking pins
- Remove screws
The room thermostat connection can then be accessed.
- Remove connector
- Connect the thermostat wires to the connector
- Reconnect connector
C
P (Fig. 29), to gain access to the reverse side
B and remove cover C (Fig. 29).
D and shunt S.
(D).
D.
Cable 240 V
Fig. 30
23
14
- If a remote time clock is to be fitted, using a volt-free switching time clock, connect the switching wires from the time
clock following points above (see also
Electrical Connections (continued)
Diagram B Fig. 31).
- If using an external time clock and room thermostat, these must be connected in series as above (see also
C Fig. 31
Live and Neutral connections to operate the clock motor must be taken from a suitable source.
Connector
please refer to those provided with the clock.
).
J12 (Fig. 30), is provided for connecting an optional integral time clock or programmer, for fitting instructions,
Diagram
24
Connector D
Connector D
Connector D
Fig. 31
15
Operating
PRESSURISING (Fig. 32)
Domestic Hot Water Circuit:
- open the cold water tap 34
- open all hot water taps until water flows
Central Heating Circuit:
- Open flow and return valves on the boiler 31 and 35
- Loosen the cap on the automatic air vent
- Open filling taps
36 and 37, and vent the radiators.
16
31
- Set the system pressure, close filling taps
remove filling loop 38.
- Check for leaks.
- Manually check pump is free to turn
Gas circuit
- open the gas tap 33
- purge the gas circuit
- test the gas circuit for soundness
33
35
34
36, 37 and
Fig. 32
SETTINGS
The boiler is supplied with all the dip switches OFF (Fig. 33) and the potentiometers turned fully anti-clockwise. It is possible
to adjust these settings as required.
In this case, it is necessary to access the electronic control unit.
Switch the power on, remove the casing and open the control unit by pressing the two side locking pins P (Fig. 29). The
setting buttons are on the circuit board behind the blanking cover E (Fig. 30)
A1 allows the Heating Anti-cycle Timing (HAT) to be set to 30 seconds or 3 minutes
HAT: Prevents the burner from relighting for the time set (30 seconds or 3 minutes) once the central heating circuit
has reached the temperature set on the Central Heating temperature knob
- A2 reserved
- A3 to fix the heating temperature setting to 40°C whatever the setting of the Central heating temperature knob 22 (Fig. 1)
A4 enables operation either in modulating heating mode, or on/off mode
-
- B1 reserved
- B2 reserved
B3 allows the hot water flow switch timing to be adjusted to 0 or 1.5 seconds
-
- B4 reserved
Note: after a power cut-out or board reset, the HAT is cancelled for 3 minutes.
P1: potentiometer to range rate the Central heating output (see table on page 26)
-
- P2: potentiometer enabling soft-light ignition (factory set at: 12.7 kW - MX2 24 FF and 16 kW - MX2 30 FF)
- P3: reserved
37
38
36
22 (Fig. 1).
Once adjustments have been made, replace the blanking cover
E (Fig. 30), close the control unit cover and refit the casing.
25
P1
P2
ON OFF
A1
A2
A3
A4
B1
B2
B3
B4
P3
Pompe Grande VitessePompe Petite Vitesse
Anticycle 3 min
Fonctionnement Modulant
Tempo Débistat Sanitaire 1,5 sec Tempo Débistat Sanitaire 0 sec
Célectic
OFF
ON
Anticycle 30 s
Fonctionnement TOR
Consigne chauffage à 40 °C
Consigne chauffage variable de 35 à 85 °C
15
Operating (continued)
Domestic hot water flow switch time 1.5 sec. Domestic hot water flow switch time 0 sec.
On/Off operation Modulating operation
Heating setting 40 °C Variable heating setting between 35 to 85°C
Anti-cycle 30 secs Anti-cycle 3 min
Fig. 33
Factory setting
Burner gas output setting
The values shown in the tables below are given for information purposes for a nominal gas distribution pressure, to allow any
adjustments to the water heater heating output according to the requirements of the system.
They cannot be used to calculate the precise regulated output of the boiler.
MX2 24
Gas : G20 PROPANE BUTANE
Power
Burner Burner Burner
(kW) Pressure Pressure Pressure
(mbar) (mbar) (mbar)
10 1.8 6.7 4.7
12.7 3.3 11.1 8.1
16 5.3 17.2 12.9
20 8.2 25.8 19.5
24 11.4 35.2 26.8
Gas : G20 PROPANE BUTANE
Power
Burner Burner Burner
(kW) Pressure Pressure Pressure
(mbar) (mbar) (mbar)
12 1.5 5.8 4.1
16 3.5 10.7 7.8
20 5.9 16.7 12.4
25 9.3 25.6 19.0
30 13.0 35.9 26.5
MX2 30
26
16
1
Fitting the casing
Remove the protective film on the casing:
- offer the casing up (Fig. 34)
- engage hooks
- fit the top of the panel in place
- close the panel mounting clamps (Fig. 35)
- screw in the clamp locking bolt
Note: it is essential to refit the locking bolt A
Fitting the Casing
N on the casing in notches R (operation 1)
A
Fig. 34
A
N
R
Fig. 35
27
17
For the Republic of Ireland it is necessary to complete a “Declaration of Conformity” to indicate compliance to I.S. 813. An
example of this is given in the current edtion of I.S. 813. In addition to this it is necessary to complete the Log Book.
Completion
18
1. The flue system must be visibly checked for soundness.
2. On Central Heating allow the system to warm up and manipulate the Central Heating temperature control knob, check the
burner modulates up and down between the high and low settings.
3. Range rate the thermal power for Central Heating, as detailed in
4. Run the Domestic Hot Water, manipulate the Domestic Hot Water temperature control knob to check the burner modulates
up and down between the high and low settings. Regulate the hot water flow rate to achieve the desired temperature rise.
5. Balance the Central Heating system until all return temperatures are correct and equal.
6. Turn the ON/OFF button OFF, disconnect the pressure Gauge, retighten screw and relight boiler.
7. Re-examine Central Heating, Domestic Hot Water and Cold Water supplies for soundness.
8. Check the appearance of the gas flame to assess the adequacy of the combustion air supply.
9. If external controls have been disconnected, reconnect and test.
10. Refit boiler casing.
Operational Checks
Section 20 (Setting the gas pressures).
19
1. Hand over this copy of the Installation, Servicing and Operating instructions supplied with the appliance, and explain how to
use the timeclock and room thermostat if fitted.
2. Show the End User how to switch the appliance off quickly, and indicate the position of the electric supply isolator.
3. Inform the End User of the location of all drains, isolating valves and air vents.
4. Explain how to turn the appliance off for both short and long periods and advise on the precautions necessary to prevent
damage in the event that the appliance is inoperative when freezing conditions occur.
5. Finally advise the End User that, for continued safe and efficient operation, the appliance must be serviced by a competent
person at least once a year.
Instructing the End User
28
20
C
D
E
F
AA
BB
When adapting to a gas different from the one for which the boiler is equipped, you should replace the parts delivered with the
conversion kit, and make the gas valve adjustments as described below:
Setting the Gas Pressures / Gas Type Conversion
Fig. 36
Fig. 37
C
D
D1
Setting the minimum and the maximum power of the boiler
Check that the supply pressure and dynamic pressure to the gas valve is a
minimum of 20 mbar for natural gas. To do this, loosen the screw
Fit the pipe of the pressure gauge to the inlet pressure connection of the gas valve
“B” check for the correct standing pressure, then operate the appliance and check
for the correct working pressure.
When you have completed this operation, replace the screw
housing to seal off the gas (check for tightness).
To check the pressure supplied by the gas valve to the burner, loosen the screw
“C”. Fit the pipe of the pressure gauge to the pressure outlet test point of the gas
valve “D”.
Disconnect the compensation pipe “D1” either from the gas valve or from the
sealed chamber.
Turn the boiler on, and ensure that the hot water temperature control knob is set to
maximum. Turn on the boiler by running a hot water tap.
Adjust the 10mm nut
the nut clockwise to increase and anti clockwise to decrease the pressure until the
required pressure is achieved (see MAXIMUM BURNER PRESSURE TABLE page 30).
To set the minimum power, disconnect a supply terminal
and adjust screw
clockwise to increase the gas pressure and counter-clockwise to decrease the gas
pressure (displayed on the pressure gauge) corresponding to the minimum power
MINIMUM BURNER PRESSURE TABLE page 30).
(see
When you have completed the above operations, turn off the hot water tap, reconnect the supply terminal to the modureg on the gas valve and replace the cap
on the screw of the modureg.
“E” on the modureg to set the maximum gas pressure, turn
“F1” from the modureg
“F” (ensure the 10mm nut is held in position). Turn the screw
“A”.
“A” securely into its
Fig. 38
Fig. 39
Setting the maximum heating circuit power
To set the maximum heating circuit power, turn the boiler on and turn the Central
Heating temperature control knob to maximum, ensuring all extermal controls are
calling for heat.
Remove the inspection panel of the P.C.B. and fit a small cross-head screwdriver
in to the right hand potentiometer (see page 26). Turn clockwise to increase the
pressure or counter-clockwise to reduce the pressure. Adjust the setting to the
required heating pressure value (displayed on the pressure gauge), as indicated in
the tables shown on page 30.
Turn off the boiler by placing the main switch to the "OFF" position.
E
Note : when adjusting the minimum output in G30/G31 on 24 FF boilers, you
should place the metal plate supplied with the boiler and the gas changing
kit on the manifold.
Important: do not forget to remove this plate once the adjustment has been
completed. (the tab prevents the boiler from being reassembled).
Adjusting the ignition output
The potentiometer P2 (Fig. 33) on the PCB permits this adjustment (12.7 kW MX2 24 FF and 16 kW - MX2 30 FF) (
Disconnect the detection electrode (see section 22.2.3 - Fig. 50).
Start the boiler and during the ignition sequence adjust the left hand potentiometer
until the gas pressure reads the required gas pressure as per the table below.
Once the gas pressure is set turn off the boiler and re-connect the detection
electrode.
NB.: It may be necessary to reset the flame failure reset a number of times during
this operation.
(Fig. 40 page 30)
see Settings on page 25).
F
Remove the pipe from the test point and tighten the screw “
test point in order to seal off the gas. Carefully check the pressure test points for
gas leaks (valve inlet and outlet), reconnect the compensation pipe
C” to the pressure
D1.
F1
IMPORTANT!
Whenever you disassemble and reassemble the gas connections, always check
for leaks using a leak detection fluid.
NOTE: ALWAYS CHECK THE GAS RATES FOLLOWING ADJUSTMENT.
29
20
Setting the Gas Pressures (continued)
Maximum Burner Pressure (mbar)
mbar G 20 G 30 G 31
Fig. 40
21
Particular Characteristics
24 kW FF
30 kW FF 13 26.5 35.9
11.4 26.8 35.2
Minimum Burner Pressure (mbar)
mbar G 20 G 30 G 31
24 kW FF
30 kW FF 1.5 4.1 5.8
1.8 4.7 6.7
Flow switch float assembly direction
By-pass valve assembly direction
30
SERVICING INSTRUCTIONS
To ensure efficient safe operation, it is recommended that the
boiler is serviced annually by a competent person.
Before starting any servicing work, ensure both the gas and
electrical supplies to the boiler are isolated and the boiler is
cool.
Before and after servicing, a combustion analysis should be
made via the flue sampling point.
After servicing, preliminary electrical system checks must be
carried out to ensure electrical safety (i.e. polarity, earth
continuity, resistance to earth and short circuit).
A
22
The life of individual components vary and they will need
servicing or replacing as and when faults develop.
The fault finding sequence chart in
which component is the cause of any malfunction, and
instructions for removal, inspection and replacement of the
individual parts are given in the following pages.
Replacement of Parts
Section 24 will help to locate
22.1 To Gain General Access
All testing and maintenance operations on the boiler
require the control panel to be lowered. This will also
require the removal of the casing.
22.1.1 Removing the front panel :
1. Unlock the two clamps locking A (see Figs. 41 & 42);
2. Remove the front panel from the rest of the
casing (see Fig. 43).
22.1.2 Removing the side panels :
1. Remove the front panel;
Fig. 41
Fig. 42
2. Remove the screws B lift toward at the base and
then lift off the locating lugs (see Fig. 44).
22.1.3 Lowering the control panel :
1. Remove the front panel;
2. Unlock the two clamps locking and pivot the
electrical box downward (see Fig. 45).
Fig. 45
Fig. 43
B
Fig. 44
31
22.2 Access to the Combustion Chamber
22.2.1 Removing the combustion chamber front panel
1. Carry out step 22.1.1;
2. Unscrew five self tapping screws “D” to release
the combustion chamber front panel and lift clear
(for the 24kW see Fig. 46a, for the 30kW see Fig. 46b);
3. Reassemble in reverse order.
24 kW
D
22.2.2 Removing the burner manifold
1. Carry out step 22.1.1 and 22.2.1;
2. Unscrew the nut between manifold and gas pipe
(see Fig. 47).
3. Unscrew the 4 screws “E” securing the burner
and lift clear (see Fig. 48).
4. Reassemble in reverse order
Fig. 47
30 kW
Fig. 48
E
Fig. 46a
D
Fig. 46b
32
Fig. 46c
22.2.3 Removing the electrodes
22.2.4 Removing the burner
1. Carry out steps 22.1.1 and 22.2.1;
2. Unscrew the self tapping screws (see Fig. 49);
3. Disconnect the lead from the wiring loom (see Fig. 50);
4. Remove the electrodes (see Fig. 51);
5. Reassemble in reverse order.
Fig. 49
1. Carry out steps 22.2.1, 22.2.1 and 22.2.2;
2. Remove the two self tapping screws “F” securing the
burner (see Fig. 48);
3. Pull the burner out of the combustion chamber (see
Fig. 53)
;
4. Remove the self tapping screws securing the
electrodes
(see Fig. 54)
5. Reassemble in reverse order;
6. Carry out combustion tests using the test point on
the turret
Fig. 50
F
Fig. 52
Fig. 53
Fig. 51
Fig. 54
33
22.2.5 Removing the main heat exchanger
1. Carry out step 22.1.1, 22.2.1 and 22.2.2;
Drain the boiler (only heating circuit);
2.
3. Remove the 2 front clips “G” securing the heat exchanger (see Fig. 55);
4. Remove the NTC clips and overheat clip (see Fig. 56);
5. Unscrew the nut “H” from the pump (see Fig. 57);
6. Remove the clip “C” from the left side hydraulic bloc, pull the 2 pipes downward (see Figs. 58 & 59);
7. Pull the heat exchanger toward you to remove (see fig. 60) ;
8. Reassemble in reverse order, do not forget to grease o rings before reassembly.
To replace insulation pads carry out the above procedure .
To remove the pads bend down the retaining clip and retract the pads.
Reassemble in reverse order
.
G
Fig. 55
C
Fig. 58
34
Fig. 56
Fig. 59
H
Fig. 57
Fig. 60
22.2.6 Removing the air pressure switch
22.2.7 Removing the fan
1. Carry out step 22.1.1;
2. Disconnect the wire connectors (see Fig. 61);
3. Disconnect the pressure pipes noting positions (see
Fig. 62 or Fig 63);
4. Remove the screw securing the pressure switch to the
chassis
5 Reassemble in reverse order ensuring that the wiring is
reconnected.
(see Fig. 64);
Fig. 61
1. Carry out step 22.1.1;
2. Disconnect the wire connectors (see Fig. 64);
3. Remove the screw fixing the fan to the flue outlet (see
Fig. 65);
4. Turn the fan anticlockwise to disengage from flue outlet
and lift clear
5. Disconnect the pressure pipes noting positions (see Fig.
;
67)
6. Reassemble in reverse order ensuring that the wiring is
reconnected correctly and the screw tightened.
(see Fig. 66);
Fig. 64
Fig. 62
Fig. 65
Fig. 66
Fig. 63
Fig. 67
35
22.3 Servicing and Removal of the Gas Valve
22.3.2 Removing the gas valve22.3.1 Removing the spark generator
1. Carry out steps 22.1.1 and 22.1.3;
2. Disconnect ignition leads “I” by pulling left (see Fig. 68);
3. Remove the two screws “J” of the electrical box (see
Fig. 69)
and disconnect the electrical connections “K”
(see Fig. 70);
4. Remove the screw “L” on the spark generator (see
Fig. 68);
5 Remove the spark generator by pulling forwards (see
Fig. 71).
L
I
Fig. 68
IMPORTANT! Ensure the gas supply to boiler is turned off.
1. Carry out step 22.1.1 and 22.1.3;
2. Disconnect the wires from the main modulator coil
M”(see Fig. 72)
“
3. Disconnect the electrode wires and remove the spark
generator as in step 22.3.1;
4. Undo the gas pipe nut “N” (30mm spanner) and the
two screws “O” securing the gas valve to the bottom
plate, and remove the electrode wire (see fig. 73);
5. Reassemble in reverse order replacing the gasket.
M
Fig. 72
J
Fig. 73
Fig. 69
N
K
Fig. 70
O
36
Fig. 71
Fig. 74
22.4 Access to the Water Circuit
Important! Before any component is removed, the boiler must be drained of all water.
22.4.1 Drain down
DHW : close the DHW inlet tap and open a tap on the installation / CH : Close the flow and return isolating valve and
open the pressure relief valve.
22.4.2 Removing the 3 way valve
1. Carry out step 22.1.1 and 22.1.3;
2. Disconnect the wire from the 3 way valve (see Fig. 75);
3. Remove the clip “P2” and the 3 way valve motor (see Fig. 76);
4. Unscrew the two screws “P3” and the 4 clips “Q1 * to Q4” (see Figs. 77 to 80);
5. Remove the 3 way valve body pulling it toward you (see Fig. 81);
6. Reassemble in reverse order;
*
See the
paragraph
19.4.1 before
removing the
clips.
Q1
Fig. 76
Fig. 77
Q2
P1
P2
Q4
Fig. 80
Q3
Fig. 75
P3
Fig. 79
Fig. 81
22.4.3 Removing the float of the flow switch
1. Remove the clip “Q1” fixing the brass connector (see Fig. 77);
2. Pull down the brass connector and catch
simultaneously the float (see Figs. 82 & 83);
3. Reassemble in reverse order;
Fig. 78
Fig. 82
Fig. 83
37
22.4.4 Removing the pressure relief valve
22.4.6 Removing the pump
1. Carry out step 22.1.1 and 22.1.3;
2. Remove the clip securing the valve (see Fig. 84) and
pull it toward you;
3. Reassemble in reverse order; take care to ensure
the valve is in the correct position;
Fig. 84
22.4.5 Removing the secondary heat exchanger
1. Carry out step 22.1.1 and 22.1.3;
2. Remove the 3 way valve motor as in step 22.4.2;
3. Disconnect the expansion vessel pipe.
3. Unscrew the two fixing screws “R” and pull it toward
(see Figs. 85 & 86a); );
you
4. Reassemble in reverse order;
The heat exchanger is so designed that it cannot be
remounted incorrectly;
1. Carry out step 22.1.1;
2. Lower the electrical box cover as in step 22.1.3
3. Remove the pump plug from the control board and
earth plug from earth socket (see Fig. 87);
4. Unscrew the pump nut (see Fig. 88);
5. Unscrew the screw “S1” and remove the clip “S2” on
the pump volute (see Fig. 89);
6. Pull the pump toward you and remove the clip “S3”
securing the pressure gauge
(see Fig. 90);
7. Reassemble in reverse order.
Fig. 87
Fig. 88
S2
R
Fig. 85
S1
Fig. 86a
Fig. 89
38
S3
Fig. 90
22.4.7 Removing the domestic expansion vessel 22.4.8 Removing the overheat thermostat
1. Remove the boiler from the wall
2. Remove the two screws “T” (see Fig. 91);
3. Unscrew the nut “U” (see Fig. 92);
4. Pull the expansion vessel toward you to remove it;
5. Reassemble in reverse order.
T
1. Remove the casing as in step 22.1.1 ;
2. Pull off the thermostat connections. Then remove
the thermostat from the pipe by releasing it’s
securing clip (see Fig. 93).
Fig. 93
22.4.9 Removing the heating temperature sensor
U
(N.T.C.)
1. Remove the casing as in step 22.1.1 ;
2. Pull off the NTC connections. Then remove the
Fig. 91
NTC from the pipe by releasing it’s securing clip
(see Fig. 94).
Fig. 92
Fig. 94
39
22.5 Access to the Control System
22.5.2 Removing the fuses
22.5.1 Removing the P.C.B.s
1. Isolate electricity;
2. Carry out step 22.1.1;
3. Pivot the electrical box downward as step 22.1.3;
4. Remove the two screws “V1” (see Fig. 95);
5. Pivot the electrical box to its original position;
6. Remove the two screws “V2” and pull toward you
unlocking the two clamps “V3” (see Fig. 96 & 97);
7. Remove the two screws “V4” (see Fig. 98) on the
PCB, unplug the electrical connections
8. To remove it pull the PCB towards you;
9. Reassemble in reverse order.
V1
1. Carry out steps 22.5.1 ;
2. Remove the fuses “X” (see Fig. 99)
3. Reassemble in reverse order.
X
Fig. 99
V2
Fig. 95
Fig. 96
V3
40
Fig. 97
V4
Fig. 98
23
If a fault occurs in the appliance, one or more LEDs (23 Fig. 1) flash according to the fault type listed in the table below.
Incorrect Operation
CODE FAULT INFORMATION
30 40 50 60 70 80
mmmmml Overheating safety feature.
mmmmll No flame detection.
mmmlml Antifrost mode on (pump in operation).
mmmllm Antifrost mode on (burner and pump in operation).
mmmlll lack of water circulation.
mmlmmm Primary water circulation defect
mmlmll Central heating return thermistor faulty (open circuit).
mmllmm Central heating return thermistor faulty (short circuit).
mmllml Central heating flow thermistor faulty (open circuit).
mmlllm Central heating flow thermistor faulty (short circuit).
mlmmlm Firing problem
mlmlmm Wiring problem (or fuse 1.25 A)
mlmlml Fan on but does not activate air pressure switch.
mlmllm Fan off but air pressure switch fails to return to off position.
mlllll Communication defect with the display PCB.
lmmmmm Communication defect with the main PCB.
m = LED off
l = LED blinking
Fault
The boiler doesn’t start
Red indicator alight
Cause
No gas, no water or no electricity
Air in the gas pipe
Room thermostat switched off
Solution
Check gas, water and electrical
supply, fuses…
Purge the gas supply
Turn up the room thermostat
Wait for a few minutes
Press the reset button
led will go out and the boiler attempts to
re-light.
25 (fig. 7) the red
Noises in CH system
Radiators rise in temperature during
summer time.
If these solutions do not cure the fault, call a qualified professional
Air presence in CH system or.
Insufficient pressure
Gravity effect in the CH system
If the red indicator lights too frequently,
please call your local service centre.
Purge the system of air and increase
the system pressure (chapter 7)
Close the heating flow isolating valve.
Don’t forget to open it again when the
heating is restarted.
41
PRELIMARY CHECKS
MAKE SURE THAT:
IS
THE POWER
L.E.D.
ON?
ESTATE
NONO
YESYES
1 - Check the fuses
2 - Check the power supply
cable, plug and outlet
3 - Check/replace the power
supply to the P.C.B.
4 - Check/replace the P.C.B
PRESS THE ON/OFF
SWITCH
CH THERMOSTAT KNOB
TURNED CLOCKWISE
A
1 - There is sufficient water in
the system
2 - The gas is turned on
3 - The electrical supply is
turned on
DHW IS BEING
DRAWN
YESYES
YESYES
DHW THERMOSTAT KNOB
TURNED CLOWCKWISE
NONO
NONO
NONO
YESYES
TURN CLOCK
AND / OR ROOM
THERMOSTAT
UP / ON
NONO
YESYES
FC P001
24
Fault Finding
24.1 Fault finding guide (flow-chart)
It is possible to detect and correct defects by using the standard fault finding diagrams described in this chapter.
NOTE: THIS FAULT FINDING GUIDE IS NOT EXHAUSTIVE.
42
IS THE PUMP
RUNNING?
NONO
NONO
YESYES
POWER T O
THE PUMP?
1 - Check that the pump
is not stuck
2 - Release/replace pump
1 - Check DHW flowswitch
2 - Check pump cable
3 - Check/replace P.C.B.
A
B
IS THE F AN
RUNNING?
NONO
POWER T O
FAN ?
YESYES
1 - Check/replace
connection cable
2 - Check/replace P.C.B.
YESYES
YESYES
1 - Replace fan
YESYES
43
IS THE BURNER
ALIGHT?
YESYES
NONO
YESYES
YESYES
NONO
NONO
NONO
YESYES
1 - Check/replace ignition
electrode
2 - Check ignition cable
3 - Check spark generator
4 - Check ignition electrode
cable
5 - Check/replace P.C.B.
1 - Check if flame strikes
detection electrode
2 - Check soft-light gas
pressure
3 - Check/replace detection
electrode
4 - Check/replace P.C.B.
1 - Check power supply of
gas valve
2 - Check/replace P.C.B.
3 - Check efficiency of
gas valve
4 - Replace gas valve
IS THE
AIR PRESSURE SWITCH
ACTIVATED?
CHECK
∆P ON TEST
PRESSURE
INTAKE
IS SPARKS
GENERATION
NORMAL?
HAS THE
BOILER SAFETY
SHUTDOWN BEEN
ACTIVATED?
1 - Check exhaust discharge
2 - Check venturi & pipes
3 - Check fan efficiency
1 - Check A.P. switch cable
2 - Check/replace A.P. switch
3 - Check/replace P.C.B.
B
C
P 1.2 mbar
P 1.2 mbar
∆
∆
>
≤
FC P003
44
Earth
Earth
IS
THERE STILL
A PROBLEM?
NORMAL
OPERATION
NONO
YESYES
FAULTS POSSIBILE CAUSES
11
22
33
44
55
66
77
88
99
C
Drawing D.H.W:
When you turn on a tap
burner switches off
Drawing D.H.W:
radiators heat up in summer mode
Drawing D.H.W:
insufficient hot water
temperature
Drawing D.H.W:
noisy operation
Decrease/increase
heating circuit pressure
Repeated shutdowns
Repeated intervention of safety thermostat
When cold water tap turned off, the boiler
ignites
Insufficient radiator temperature
- air in secondary heat exchanger
- faulty D.H.W. flow switch
- faulty 3-way valve / gravity effect (see
page 41)
- check temperature probes
- check gas pressures
- check water flow rate
- check secondary heat exchanger
- primary heat exchanger faulty or
lime-scale deposits
- low heating system water pressure
- check gas pressures
-
check temperature probes
- check for leaks on the heating circuit
- faulty filling-loop
- faulty secondary heat exchanger
- expansion vessel faulty
- faulty detection electrodes
- check gas settings
- check flame detection electric circuit
-
check temperature probes
- overheat thermostat not calibrated correctly
- air in primary water circuit
- drop in pressure in the water mains, with
consequent water hammer
- check C.H. temperature probe
- check by-pass
- check gas pressures
25
Electrical Diagrams
45
26
Short Spare Parts List
MX2 24 / MX2 30
SHORT LIST
104
108
110
206
216
401
444
537
543
524
589
502
506
531
532
538
615
616
623
650
622
649
DescriptionKey N°
104 OVERHEAT THERMOSTAT 105°C 61010191
108 THERMISTOR TEMP. SENSOR 990686
110 IGNITIONELECTRODE 990436
206 FAN ASSY 24FF 61310933
FAN ASSY 30FF 61304721
216 AIR PRESSURE SWITCH 61313340
AIR PRESSURE SWITCH 61313932
401 GAS VALVE 61312123
444 IGNITER 61312612
524 DHWFLOW SWITCH FLOAT 61311314
531 AIRSEPARATOR 61304608
532 GASKET KIT 61304618
538 PUMP + AIRSEPARATOR 61301964
537 PRESSURE RELIEF VALVE 61312668
543 STOPPED WATER THROTTLE 61311745
589 WATER / WATER HEAT EXCHANGER 61302409
615 P.C.B. 65100774
616 PRINTED CIRCUIT BOARD (DISPLAY) 61400240
622 BUTTONS 61312414
623 IGNITION PUSH ROD 61313385
649 PRESSURE GAUGE 61313561
650 WHITE KNOB 61312413
G.C N°
Manf. Pt. N°
Type
FF FF
..
..
..
.
.
.
.
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
MX2 24
MX2 30
Manf. date
from to
46
NOTES
47
27
Technical Data
Model MX2 24 FF MX2 30 FF
Appliance Category............................................................. II 2H3+ II 2H+3+
Heat output C/H .....................................................Pw 10 to 24 kW 12 to 30 kW
Heat output DHW ..........................................Pw max 24 kW 30 kW
DHW flow rates (∆T: 30 K) ................................................. 11.4 I/min. 14.3 I/min.
Minimum DHW operating flow rate...................................... 2 l/min 2 l/min
Minimum DHW working pressures .................Pw min 0.1bar 0.1bar
Maximum DHW working pressures ...............Pw max 10 bar 10 bar
C/H circuit pressure max operating ...............Pw max 3 bar 3 bar
Supply ................................................................................. 230 volts - 50 Hz
Consumption....................................................................... 150 W
Protection............................................................................ IP X4D
o
Designed temperature rise.................................................. 20
Natural gas G20
Gas rate max....................................................................... 2.75 m3/h 3.44 m3/h
Gas rate mini....................................................................... 1,27 m
Nominal inlet pressure......................................................... 20 mbar 20 mbar
Burner injector diameter ..................................................... 1.35mm 1.30mm
Butane LPG G30
Gas rate max....................................................................... 2.05 kg/h 2.56 kg/h
Gas rate mini....................................................................... 0.95 kg/h 1.12 kg/h
Nominal inlet pressure......................................................... 28 mbar 28 mbar
Burner injector diameter ..................................................... 0.80mm 0.80mm
C20
3
/h 1.50 m3/h
o
C
Propane LPG G31
Gas rate max....................................................................... 2.02 kg/h 2.52 kg/h
Gas rate mini....................................................................... 0.93 kg/h 1.10 kg/h
Nominal inlet pressure......................................................... 37 mbar 37 mbar
Burner injector diameter ..................................................... 0.80mm 0.80mm
Flue Lengths
Max (Horizontal ø60/100).................................................... 4 metres 4 metres
Max (Vertical
Max (Horizontal
Max (Vertical
ø60/100)........................................................ 4 metres 4 metres
ø80/125).................................................... 13 metres 18 metres
ø80/125)........................................................ 13 metres 18 metres
This appliance is suitable for Natural gas or LPG. A gas conversion must be made by a competent person.
Chaffoteaux & Maury are continuously improving their products and therefore reserve the right to change specifications without
prior notice and accepts no liability for any errors or omission in the information contained in this document.
Manufacturer: Chaffoteaux & Maury - France
Commercial subsidiary: MTS (GB) Limited
MTS Building
Hughenden Avenue
High Wycombe
Bucks HP13 5FT
Telephone: (01494) 755600
Fax: (01494) 459775
Internet: www.chaffoteaux.co.uk
E-mail: info@mtsgb.ltd.uk
Technical Support Help Line: 0870 241 8180
Customer Service Help Desk: 0870 600 988
1313374c - 12/2003
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