A/23 MFFI - A/27 MFFI
G.C.N. 47-116-10 / 47-116-12
Installation Instructions
Type C Boilers
LEAVE THESE INSTRUCTIONS
ADJACENT TO THE GAS METER
Country of destination: GB
This manual is an integral and essential part of the product. It should be kept
with the appliance so that it can be consulted by the user and our authorised
personnel.
1.
GENERAL
INFORMATION
Please carefully read the instructions and notices about the unit contained in
this manual, as they provide important information regarding the safe
installation, use and maintenance of the product.
For operating instructions please consult the separate User’s Manual.
User’s
Manual
A/23 MFFI
A/27 MFFI
Read the instructions and recommendations in these Installation Instructions
carefully to ensure proper installation, use and maintenance of the appliance.
1.1
General Instructions
Keep this manual in a safe place. You may need it for your own reference while
our Servicing Centre technicians or your installer may need to consult it in the
future.
This is a combined appliance for the production of central heating (C.H.) and
domestic hot water (D.H.W.).
This appliance must be used only for the purpose for which it is designed.
The manufacturer declines all liability for damage caused by improper or
negligent use.
No asbestos or other hazardous materials have been used in the fabrication of
this product.
Before connecting the appliance, check that the information shown on the data
plate and the table on pages 4-5 comply with the electric, water and gas mains
of the property.You will find the data plate on the reverse of the control panel.
The gas with which this appliance operates is also shown on the label at the
bottom of the boiler.
Do not install this appliance in a damp environment or close to equipment
which spray water or other liquids.
Do not place objects on the appliance.
Do not allow children or inexperienced persons to use the appliance without
supervision.
If you smell gas in the room, do not turn on light switches, use the telephone or
any other object which might cause sparks.
Open doors and windows immediately to ventilate the room.
Shut the gas mains tap (on the gas meter) or the valve of the gas cylinder and
call your Gas Supplier immediately.
If you are going away for a long period of time, remember to shut the mains gas
tap or the gas cylinder valve.
Always disconnect the appliance either by unplugging it from the mains or
turning off the mains switch before cleaning the appliance or carrying out
maintenance.
In the case of faults or failure, switch off the appliance and turn off the gas
tap. Do not tamper with the appliance.
For repairs, call your local Authorised Servicing Centre and request the use of
original spare parts. For in-guarantee repairs contact MTS (GB) Limited.
Check the following at least once a year:
1 - Check the seal of water connections, replacing the gaskets if necessary.
2 - Check the seal of the gas connections, replacing the gaskets if necessary.
3 - Check the general condition of the appliance and of the combustion
3
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chamber visually.
4 - Visual check of the combustion: clean burners if necessary.
5 - With reference to point 3, dismantle and clean the combustion chamber if
necessary.
6 - With reference to point 4, dismantle and clean the injectors if necessary.
7 - Visual check of the primary heat exchanger:
- check for overheating of the exchangers fins;
- clean the exhaust side of the exchanger and fan if necessary.
8 - Regulate the gas pressure, ignition pressure, partial flame, maximum
flame.
9 - Check proper operation of the heating safety system:
- maximum safety temperature;
- maximum safety pressure.
10 - Check the proper operation of the gas safety system:
- gas or flame safety device;
- gas valve safety device.
11 - Check that the electrical connections have been made in compliance with
the instructions shown in the installation instructions.
12 - Check the efficiency of the hot water supply (flow and temperature).
13 - Check general operation of the appliance.
14 - Check the exhaust system for the combustion products.
1.2
Technical Information
A/23 MFFI
A/27 MFFI
CE Certification
29.8/12.0
27.3/10.1
91.6
Heat Input
Heat Output
max/min kW
max/min kW
25.6/11.0
23.1/9.2
90.2
Efficiency of Nominal Heat Input
Efficiency at 30% of Nominal Heat Input
Heat Loss to the Casing (³T=50°C)
Flue Heat Loss with Burner Operating
Flue Heat Loss with Burner Off
%
%
%
%
%
88.3
1.3
7.1
0.4
87.8
1.2
8.6
0.4
62
1.4
3.16/3.86
0.37/0.45
2.35/2.32
Maximum Discharge of Fumes (G20-G25) Kg/h
Residual Discharge Head mbar
59
1.15
2.72/3.32
0.32/0.39
2.02/2.00
Consumption at Nominal Capacity (G20-G25)m3/h
Gas Consumption after 10 Minutes*
(15°C, 1013 mbar) (G30-G31)
Temp. of exhaust fumes at nominal
capacity (G20-G25)
m3
Kg/h
128
6.6
°C
%
137
5.8
2
CO Content
2
8.0
O Content
%
9.2
34
+5
CO Content
Minimum Ambient Temperature
ppm
°C
32
+5
200
Head Loss on Water Side (max) (³T=20°C) mbar
200
0.25
82/42
56/36
11.2
2.5
2.6
6/0.2
7
Residual Head of System
Heating Temperature
bar
max/min °C
max/min °C
l/min
gal/min
l/min
max/min bar
l
0.25
82/42
56/36
9.5
2.1
2.6
6/0.2
7
1
145
3
Domestic Hot Water Temperature
D.H.W. Flow Rate ³T=35°C
D.H.W. Flow Rate ³T=35°C
D.H.W. Minimum Flow Rate
Pressure of Domestic Hot Water
Expansion Vessel Capacity
Expansion Vessel Pre-load Pressure
Maximum Water Content in System
Maximum Heating Pressure
1
145
3
bar
l
bar
20-25
30-37
230 / 50
190
Nominal Pressure Natural Gas (G20-G25) mbar
20-25
30-37
230 / 50
150
LPG
(G30-G31) mbar
Electrical Supply
Power Consumption
V/Hz
W
44
Protection Grade of Electrical System
Internal Fuse Rating
Weight
IP
44
FAST 2 AT
47
FAST 2 AT
47
Kg.
47-116-12
G.C. Number
47-116-10
*Calculated at 70% maximum output
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4
1.3
Overall View
A/23 MFFI - A/27 MFFI
Fig. 1.1
Legend:
1. Flue Connector
14. Drain Valve
2. Combustion Chamber Hood
3. Main Heat Exchanger
4. Combustion Chamber Insulation Panel
5. Burner
15. Secondary Heat Exchanger
16. Safety Valve (3 bar)
17. Circulation Pump with Automatic Air Release Valve
18. Gas Valve
6. Expansion Vessel
7. Overheat Thermostat
8. Spark Generator
19. Detection Electrodes
20. Ignition Electrodes
21. Fan
9. Diverter Valve
22. Venturi
10. Main Circuit Temperature Probe
11. Main Circuit Flow Switch
12. Diverter Valve Microswitch
13. Filter Seat
23. Air Pressure Switch
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5
The technical information and instructions provided herein below are intended
for the installer so that the unit may be installed correctly and safely.
2.
INSTALLATION
The installation and initial start up of the boiler must be by a CORGI Approved
Installer in compliance with the installation standards currently in effect, as well
as with any and all local health and safety standards i.e. CORGI .
2.1
Reference Standards
This appliance must be installed by a competent installer in
accordance with the 1984 Gas Safety (installation & use)
Regulations (as amended)
The installation of this appliance must be in accordance with the relevant
requirements of the 1984 Gas Safety (installation & use) Regulations, the Local
Building Regulations, the current I.E.E. Wiring Regulations, the byelaws of the
local water authority, and in Scotland, in accordance with the Building
Standards (Scotland) Regulation and Health and Safety document No. 635
“Electricity at work regs. 1989”.
Installation should also comply with the following British Standard Codes of
Practice:
Low pressure
pipes
BS 6891
BS 6798
BS 5449
1988
1987
1990
Boilers of rated input
not exceeding 60 kW
Forced circulation hot
water system
Installation of gas hot water
supplies for domestic purposes
( 2nd family gases)
Flues
BS 5546
BS 5440-1
BS 5440-2
1990
1990
1989
Air supply
The appliance may be installed in any room or indoor area, although particular
attention is drawn to the requirements of the current I.E.E. Wiring Regulations,
and in Scotland, the electrical provisions of the Building Regulations applicable
in Scotland, with respect to the installation of the combined appliance in a room
containing a bath or shower.
2.2
Siting the Appliance
Where a room-sealed appliance is installed in a room containing a bath or
shower the boiler and any electrical switch or appliance control, utilising
mains electricity should be situated so that it cannot be touched by a
person using the bath or shower.
The location must permit adequate space for servicing and air circulation
around the appliance as indicated in paragraph 2.4.
The location must permit the provision of an adequate flue and termination.
For unusual locations special procedures may be necessary.
BS 6798-1987 gives detailed guidance on this aspect.
A compartment used to enclose the appliance must be designed specifically for
this purpose. No specific ventilation requirements are needed for an installation
within a cupboard
This appliance is not suitable for outdoor installation.
The type C appliances (in which the combustion circuit, air vent intake
and combustion chamber are air-tight with respect to the room in which
the appliance is installed) can be installed in any type of room.
There are no limitations with respect to ventilation and the volume of the room
itself. The boiler must be installed on a solid, permanent wall to prevent access
to the electrical parts (when live) through the aperture on the back frame.
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2.3
Overall Dimensions
(A-B-D-E)
(C)
Fig. 2.1
Legend:
A = Central Heating Flow (3/4”)
B = Domestic Hot Water Outlet (1/2”)
C = Gas Inlet (3/4”)
D = Domestic Cold Water Inlet (1/2”)
E = Central Heating Return (3/4”)
In order to allow for access to the interior of the boiler for maintenance purposes, the
boiler must be installed in compliance with the minimum clearances indicated in the
diagram below.
2.4
Clearances
A/23 MFFI - A/27 MFFI
60
60
450
40 50 60 70 80
C
C
300
Fig. 2.2
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7
Fasten the boiler in place using the template and anchors supplied with the
unit. It is highly recommended that a spirit level be used to position the boiler so
that it is perfectly level.
For additional information, please consult the instructions contained in the
connection kit and the flue kit.
2.5
2.6
Mounting the Appliance
Electrical Connection
For safety purposes, have a competent person carefully check the electrical
system in the property, as the manufacturer will not be held liable for damage
caused by the failure to earth the appliance properly or by anomalies in the
supply of power. Make sure that the residential electrical system is adequate for
the maximum power absorbed by the unit, which is indicated on the rating plate.
In addition, check that the section of cabling is appropriate for the power
absorbed by the boiler.
The boiler operates with alternating current, as indicated in the technical data
table (1.2), where the maximum absorbed power is also indicated. Make sure
that the connections for the neutral and live wires correspond to the indications
in the diagram. The appliance electrical connections are situated on the reverse
of the control panel (see the servicing manual for further information)
Fig. 2.3
Important!
In the event that the power supply cord must be changed, replace it with one
with the same specifications. Make the connections to the terminal board
located within the control panel, as follows:
- The yellow-green wire should be connected to the terminal marked with the
earth symbol; make sure to re-use the ferrule mounted on the other supply
cord;
- The blue wire should be connected to the terminal marked “N”;
- The brown wire should be connected to the terminal marked “L”.
Note: The diagrams for the electrical system are indicated in section 2.11.
Warning, this appliance must be earthed.
External wiring to the appliance must be carried out by a qualified technician
and be in accordance with the current I.E.E. Regulations and applicable local
regulations. The EuroCombi range of boilers are supplied for connection to a
230 V~ 50 Hz supply.
The supply must be fused at 3 A.
The method of connection to the electricity supply must facilitate complete
electrical isolation of the appliance, by the use of a fused double pole isolator
having a contact separation of at least 3 mm in all poles or alternatively, by
means of a 3 A fused three pin plug and unswitched shuttered socket outlet
both complying with BS 1363.
The point of connection to the electricity supply must be readily accessible and
adjacent to the appliance unless the appliance is installed in a bathroom when
this must be sited outside the bathroom.
The local gas region contractor connects the gas meter to the service pipe.
If the gas supply for the boiler serves other appliances ensure that an adequate
supply is available both to the boiler and the other appliances when they are in
use at the same time.
2.7
Gas Connection
Pipe work must be of an adequate size. Pipes of a smaller size than the boiler
inlet connection should not be used.
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8
2.9
Water Connections
A/23 MFFI - A/27 MFFI
C
A
B
D
E
I
Fig. 2.4
Legend
A = Central Heating Flow
B = Domestic Hot Water Outlet
C = Gas Inlet
D = Domestic Cold Water Inlet
E = Central Heating Return
I = Safety Valve
Central Heating
Detailed recommendations are given in BS 6798:1987 and BS 5449-1:1990,
the following notes are given for general guidance.
Pipe Work:
Copper tubing to BS EN 1057:1996 is recommended for water pipes. Jointing
should be either with capillary soldered or compression fittings.
Where possible pipes should have a gradient to ensure air is carried naturally
to air release points and water flows naturally to drain taps.
The appliance has a built-in automatic air release valve, however it should be
ensured as far as possible that the appliance heat exchanger is not a natural
collecting point for air.
Except where providing useful heat, pipes should be insulated to prevent heat
loss and avoid freezing.
Particular attention should be paid to pipes passing through ventilated spaces
in roofs and under floors.
By-pass:
The appliance includes an automatic by-pass valve, which protects the main
heat exchanger in case of reduced or interrupted water circulation through
the heating system, due to the closing of thermostatic valves or cock-type
valves within the system.
System Design:
This boiler is suitable only for sealed systems.
Drain Cocks:
These must be located in accessible positions to permit the draining of the
whole system. The taps must be at least 15mm nominal size and
manufactured in accordance with BS 2870:1980.
Safety Valve Discharge:
The discharge should terminate facing downwards on the exterior of the
building in a position where discharging (possibly boiling water & steam) will
not create danger or nuisance, but in an easily visible position, and not cause
damage to electrical components and wiring.
The discharge must not be over an entrance or a window or any other type of
B023
9
public access.
Air Release Points:
These must be fitted at all high points where air naturally collects and must
be sited to facilitate complete filling of the system.
The appliance has an integral sealed expansion vessel to accommodate the
increase of water value when the system is heated.
It can accept up to 7 l (1.5 gal) of expansion water. If the heating circuit has
an unusually high water content, calculate the total expansion and add an
additional sealed expansion vessel with adequate capacity.
Mains Water Feed - Central Heating:
There must be no direct connection to the mains water supply even through a
non-return valve, without the approval of the Local Water Authority.
Filling:
A temporary method for initially filling the system and replacing lost water
during servicing in accordance with Water Supply Byelaw 14 must be
provided.
Domestic Water
The domestic water must be in accordance with the relevant recommendation
of BS 5546:1990. Copper tubing to BS EN 1057:1996 is recommended for
water carrying pipe work and must be used for pipe work carrying drinking
water.
Residual Head of the Boiler
Flue System
2.9 Flue Connections
The provision for satisfactory flue termination must be made as described
in BS 5440-1.
The appliance must be installed so that the flue terminal is exposed to outdoor air.
The terminal must not discharge into another room or space such as an
outhouse or lean-to.
It is important that the position of the terminal allows a free passage of air
across it at all times.
The terminal should be located with due regard for the damage or
discolouration that might occur on buildings in the vicinity.
In cold or humid weather water vapour may condense on leaving the flue
terminal.
The effect of such "steaming" must be considered.
If the terminal is less than 2 metres above a balcony, above ground or above a
flat roof to which people have access, then a suitable terminal guard must be
fitted. When ordering a terminal guard, quote the appliance model number.
A suitable terminal guard is available from:
TOWER FLUE COMPONENTS
Morley Road
Tonbridge
Kent TN9 1RA
The minimum acceptable spacing from the terminal to obstructions and
ventilation openings are specified in Fig. 2.5.
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10
TERMINAL POSITION
mm
A - Directly below an open window or other opening
B - Below gutters, solid pipes or drain pipes
C - Below eaves
D - Below balconies or car-port roof
E - From vertical drain pipes and soil pipes
F - From internal or external corners
G - Above ground or below balcony level
H - From a surface facing a terminal
I - From a terminal facing a terminal
J - From an opening in the car port
300
75
200
200
75
300
300
600
1200
BC
F
G
F
D
J
HI
A
E
K
L
( e.g. door, window ) into dwelling
K - Vertically from a terminal in the same wall
L - Horizontally from a terminal in the same wall
1200
1500
300
G
Fig. 2.5
The boiler is designed to be connected to a coaxial flue discharge system.
Ø 60/100 mm
Fig. 2.6
In addition, it is also possible to use a twin-pipe (split) system by fitting a special
adaptor to the flue discharge collar and using one of the apertures for the air
vent intake located on the top part of the combustion chamber (A).
Fig. 2.7
Ø 80 mm
A
A
A
Ø 80 mm
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11
This procedure must be done as follows:
1 - Remove the air vent intake you want to use, in the area indicated in
Fig. 2.8, by breaking the perforated ring.
2 - Use a tool to grasp the lid and remove it completely.
3 - Clean any burrs or sharp edges with a knife or an appropriate tool.
A
Fig. 2.8
Fig. 2.9
In Fig. 2.10 below, several different types of flue systems are shown.
For additional information regarding the flue accessories, please consult the
Flue Pipe Accessories manual.
Fig. 2.10
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12
Maximum Extension Diameter of Pipes
Use of a Restrictor
on the Discharge Side
ExhaustType
Risk of Condensation Forming
Exhaust/Air
(mm)
C12 (xx)
C32 (xx)
C42 (xx)
4 m
4 m
4 m
ø 60 /100
ø 60 /100
ø 60 /100
L* < 0.5 m
L* < 0.5 m
L* < 0.5 m
Coaxial
System
23 kW
27 kW
C12 (xy)
C32 (xy)
C42 (xy)
C52 (xy)
54 m
54 m
54 m
17 m
46 m
46 m
46 m
17 m
ø 80
ø 80
ø 80
ø 80
L < 7 m (23 kW) L < 5 m (27 kW)
L < 7 m (23 kW) L < 5 m (27 kW)
L < 7 m (23 kW) L < 5 m (27 kW)
L < 7 m (23 kW) L < 5 m (27 kW)
L > 4 9 m (23 kW) L > 6.5 m (27 kW)
L > 4.9 m (23 kW) L > 6.5m (27 kW)
L > 4.9m (23 kW) L > 6.5m (27 kW)
L > 4.9m (23 kW) L > 5.3m (27 kW)
Twin Pipe
Systems
(*) L = Length of Piping
In calculating the lengths of the pipes, the maximum length must also take into
consideration the values for the exhaust/air intake end terminals, as well as 90°
elbows for coaxial systems.
The C52 types must comply with the following requirements:
1. The discharge/intake vent pipes must have the same diameter of ø 80 mm.
2. The maximum combined flue length is 17 m. In this case the minimum length
for the air intake pipe is 1 meter; the maximum length of vertical
exhaust pipe must be a maximum of 12 m.
3. If an elbow is inserted into the discharge/ventilation system, the calculation
of the overall extension must take into consideration the values for each
curve, as indicated in the table.
4. The exhaust pipe must extend at least 0.5 m above the ridge of the roof if it is
located on a side other than that for the air intake (this is not obligatory if
the exhaust and air intake pipes are located on the same side of the
building).
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13
In order to perform this procedure, remove boiler cover as indicated in section
3.2. Then proceed as follows:
2.10 Room Thermostat
Connection
1 Remove the screws “A” located on the bottom part of the boiler;
2 Widen the sides so that the control panel can be rotated.
3 Open the cover “B” on the left hand side of the compartment.
4 Insert the wire for the connection of the room thermostat into the wire
holder “C”, as indicated in photo 3.
1
2
A
3
4
C
B
5 Remove the grommet “D” shown in photo 5, make a hole in it and pass
the room thermostat wire through.
6 Remove the link located on the terminal and connect the wire.
7 Replace the grommet and the terminal to their original positions, close the
cover on the grommet compartment and fasten the wire-clamp “C” in place.
8 If a remote time clock is to be fitted, disconnect the integral time clock plug
from the P.C.B.
9 Using a volt-free switching time clock, connect the switching wires from the
time clock following points 1-7 above.
10If using a time clock and room thermostat, these must be connected in
series as per points 1-9 above.
Note: Only a two-wire type room thermostat can be used.
5
7
6
D
C
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14
Legend:
2.11 Electrical Diagram
AT = High Voltage P.C.B.
BT = Low Voltage P.C.B.
B
C
D
E
F
G
H
I
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
Flame Failure L.E.D.
Insufficient Water Pressure L.E.D.
Water Temperature Indicator L.E.D.s
Overheat Thermostat Warning L.E.D.
System Reset Button
Selector Knob for Operating Mode
Domestic Hot Water Temp. Adjustment
Central Heating Temp. Adjustment
Wire Connector for Room Thermostat
Connector for Total Check System
Anti-cycling Device Adjustment for Heating
Soft-light Adjustment
Max Heating Temperature Adjustment
Time Clock Connection
On/Off L.E.D.
On/Off Switch
Interface Wire for P.C.B.s
Relay Motorised Valve
J
K
M
N
O
P
Q
R
S
T
U
V
W
X
Ignitor Relay
Gas Valve Relay
Fan Relay
Circulation Pump Relay
Aa = Adaptor (British Gas use only)
Selector TCS2
Y
=
A01 = Air Pressure Switch
A02 = Fan
A03 = Gas Valve
A04 = Ignitor
A05 = Motorised Valve
A06 = Circulation Pump
A07 = Flame Detector
A08 = Earth Terminal
A09 = Flame Detection Circuit
A10 = Flame Indicator L.E.D.
A11 = Transformer
A12 = Filter
B01 = Over Heat Thermostat
B02 = Room Thermostat
B03 = Gas Valve Modulator
B05 = Heating Sensor
B06 = Pressure Switch for Heating Circuit
B07 = Microswitch for Diverter Valve
Colours
Gry
Rd
Bl
= Grey
= Red
= Blue
Grn/Yll = Yellow/Green
Wh
Brn
Blk
= White
= Brown
= Black
Wh/Rd = White/Red
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A/23 MFFI - A/27 MFFI
A/23 MFFI - A/27 MFFI
B023
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2.12 Water Circuit Diagram
Legend
1. Air Pressure Switch
2. Fan
A/23 MFFI - A/27 MFFI
3. Main Heat Exchanger
4. Main Burner
5. Ignition Electrodes
Detection Electrode
6. Gas Valve
7. Overheat Thermostat
8. Main Circuit Temperature Probe
9. Diverter Valve
10. Main Circuit Flow Switch including
Safety Pressure Switch for
Primary Circuit
11. Automatic By-pass
12. Microswitch for Diverter Valve
13. Secondary Heat Exchanger
14. Domestic Water Inlet Filter
15. Boiler Drain Valve
16. Safety Valve
17. Water Pressure Gauge
18. Circulation Pump with Automatic
Air Release Valve
3
COMMISSIONING
19. Expansion Vessel
Preliminary electrical system checks to ensure electrical safety must be carried
out by a competent person i.e. polarity, earth continuity, resistance to earth and
short circuit.
3.1
Initial Preparation
Filling the Heating System:
Remove the panels of the case and lower the control panel (see point 3.2. for
further information).
Open the central heating flow and return cocks supplied with the connection
kit.
Unscrew the cap on the automatic air release valve one full turn and leave
open permanently.
Close all air release valves on the central heating system.
Gradually open valve(s) at the filling point (filling-loop) connection to the
central heating system until water is heard to flow, do not open fully.
Open each air release tap starting with the lower point and close it only when
clear water, free of air, is visible.
Purge the air from the pump by unscrewing anticlockwise the pump plug and
also manually rotate the pump shaft in the direction indicated by the pump
label to ensure the pump is free.
Close the pump plug.
Continue filling the system until at least 1 bar registers on the pressure
gauge.
Inspect the system for water soundness and remedy any leaks discovered.
Filling of the D.H.W. System:
Close all hot water draw-off taps.
Open the cold water inlet cock supplied with the connection kit.
Open slowly each draw-off tap and close it only when clear water, free of
bubbles, is visible
Gas Supply:
Inspect the entire installation including the gas meter, test for soundness and
purge, all as described in BS 6891:1988.
Open the gas cock (supplied with the connection kit) to the appliance and
check the gas connector on the appliance for leaks.
When the installation and filling are completed turn on the central heating
B023
17
system (sect. 3.4) and run it until the temperature has reached the boiler
operating temperature. The system must then be immediately flushed through.
The flushing procedure must be in line with BS 7593:1992 Code of practice for
treatment of water in domestic hot water central heating systems.
During this operation, we highly recommend the use of a central heating
flushing detergent (Fernox Superfloc or equivalent), whose function is to
dissolve any foreign matter that may be in the system.
Substances different from these could create serious problems to the
pump or other components.
The use of an inhibitor in system such as Fernox MB-1 or equivalent is strongly
recommended to prevent corrosion (sludge) damaging the boiler and system.
Failure to carry out this procedure may invalidate the appliance warranty.
To remove the front panel of the casing, proceed as follows:
1. Remove the screw “F” located on the top edge of the panel.
2. Lift and unhook the panel.
3.2 Removing the
Front Panel
F
1
2
3.3 Control Panel
A/23 MFFI - A/27 MFFI
40 50 60 70 80
C
C
A - Ignition Lockout Reset Button/Safety (Overheat)Thermostat Reset
B - Ignition Lockout L.E.D.
C - Selector Knob for Summer/Winter/Flue Analysis Modes*
D - Low System Water Level L.E.D.
E - Temperature Adjustment Knob for Domestic Hot Water
F - Heating System Thermometer
G - Safety (Overheat)Thermostat Intervention L.E.D.
H - Adjustment Knob for Heating Temperature
I - On/Off L.E.D.
L - On/Off Switch
O - System Pressure Gauge
* Warning the flue analysis mode must only be selected by a qualified service engineer.
18
B023
The checks to be run before initial start-up are as follows:
1. Make sure that:
3.4
3.5
B023
Initial Start-up
-the screw on the automatic air valve has been loosened when the
system is full;
- If the water pressure in the system is below 1 bar, bring it up to the appro-
priate level;
-Check to see whether the gas cock is closed;
-Make sure that the electrical connection has been made properly and that
the earth wire is connected to an efficient earthing system;
- Supply power to the boiler by pressing the On/Off switch <L> - the L.E.D. “I”
will turn on - turn the selector knob “C” to the <winter> setting. This will start
the circulation pump. After 7 seconds, the boiler will signal a shut-
down due to failure ignition. Leave the boiler as it is until all of the air has
been bled from the lines.
-Loosen the cap on the head of the pump to eliminate any air pockets;
-Repeat the procedure for bleeding the radiators of air;
-Open the taps for a brief period;
-Check the system pressure and, if it has dropped, open the filling-loop
again to bring the pressure back up to 1 bar.
2. Check the exhaust flue for the fumes produced by combustion.
3. Make sure that all gate valves are open;
4. Turn on the gas cock and check the seals on the connections, including the
one for the burner, making sure that the meter does not signal the passage
of gas. Check the connections with a soap solution and eliminate any leaks.
5. Press the reset button “A” for the lighting system; the spark will light the
main burner. If the burner does not light the first time, repeat the procedure.
6. Check the minimum and maximum pressure values for the gas going to the
burner; adjust it if needed using the values indicated in the table in
section 4.
(See the relative section for burner pressure adjustment within the servicing
manual).
The boiler was designed to make it easy to regulate and check the various
features. To access the areas where the adjustment and control devices are
located, simply remove the plugs by pressing from the inside, unscrew the
screws “A” and remove the bottom part of the instrument panel, rotating it
upward.
Operational
Adjustments
Right hand side service panel also provides access to:
- the power supply cord connector;
- the fuses.
Left hand side:
- the potentiometer for regulating the ignition delay (anti-cycling) feature, which
can be set from 0 to 2 minutes (factory set at 1 minute);
- the potentiometer for regulating the soft-light feature, the setting for which
can range from the minimum thermal power to the maximum:
19
G20
G25
5.5 mm c.a.
4.5 mm c.a.
G30-31 1.8 mm c.a.
- the potentiometer for the maximum thermal power for the heating system,
maximum thermal power setting (factory set at the maximum value, unless
indicated otherwise on the adhesive sticker located in proximity to the
potentiometer);
- The connection for the diagnostic device (TCS-TCS2).
The boiler is designed to make it easy to analyse the combustion by-products.
3.6
Combustion Analysis
Using the especially designed apertures, readings can be taken on the
temperature of the combustion by-products and of the combustion air, as well
2
2
as of the concentrations of O and CO , etc.
The best maximum-power test conditions for the heating system are when the
selector “C” is turned to the flue analysis setting.
The discharge/ventilation of the exhaust fumes can be monitored to check for
losses in general pressure in the system. This is done to eliminate the cause of
lighting failure with the main burner not indicated by a shutdown status.
With a differential manometer connected to the test socket on the combustion
chamber, the DP value for the air pressure switch can be taken. The measured
value should not be less than 10 mbar under maximum thermal power
conditions (with the knob “C” on the flue test setting) in order for the unit to
function properly and without interruption.
3.7
Fume Discharge
Monitoring
The boiler is equipped with the following safety systems (see section 3.3 for
references):
3.8
Boiler Safety Systems
1 - Ignition Failure
This control signals an ignition failure on the burner 7 seconds after a lighting
failure. The L.E.D. “B”.will turn on to signal the shutdown status.
The system can be reset by pressing and releasing the button “A” after
checking to make sure that the gas valve is open. Repeat this process until the
burner lights.
2 - Circulation Failure
This control signals that the safety pressure switch on the primary circuit has
not sensed a pressure of at least 1 bar within 40 seconds of the activation of
the circulation pump, it shuts off the boiler and lights the L.E.D. “D”. The system
can be reset (after the pressure has been brought up to the proper level) by
using the On/Off switch “L”.
3 - Overheating
This control shuts off the boiler in the case where the primary circuit reaches a
temperature in excess of 110°C. The L.E.D. “G” will come on to signal this shut
B023
20
off status. After the system has been allowed to cool, the system can be reset
by pressing the button “A”.
4 - Limescale Build-up
This is an indirect control (actuated through the regulation of the temperature in
the primary heat exchanger) on the formation of limescale in the secondary
heat exchanger. Regardless of the flow rate and the temperature in the circuit
for the domestic hot water, the temperature is limited to 62°C.
5 - Safety Shut-off
At the start of every lighting phase, the P.C.B. performs a series of internal
controls. If a malfunction occurs, the boiler will shutdown until the problem has
been resolved.
Draining the heating system.
The heating system must be emptied as follows:
3.9
Draining the System
- Turn off the boiler;
- Open the drain valve for the system and place a container below to catch the
water that comes out;
- Empty the system at the lowest points (where present). If you plan on not
using the heating system for an extended period of time, it is recommended
that you add antifreeze with an ethylene glycol base to the water in the
heating lines and radiators if the ambient temperature drops below 0°C during
the winter.
This makes repeated draining of the entire system unnecessary.
Draining the domestic hot water system.
Whenever there is the danger of the temperature dropping below the freezing
point, the domestic hot water system must be drained as follows:
- Turn off the general water valve for the household plumbing system;
- Turn on all the hot and cold water taps;
- Empty the remaining water from the lowest points in the system (where
present).
4.
GAS ADJUSTMENTS
CATEGORY II2H3+
Methane Gas
G20
Liquid Butane Gas Liquid Propane Gas
G30
G31
3
Lower Wobbe Index (15°C;1013mbar)
Nominal Delivery Pressure
Minimum Delivery Pressure
MJ/m h
mbar
mbar
45.67
20
17
80.58
30
70.69
37
20
25
A/23 MFFI
Main Burner: n. 13 jets (ø)
Consumption (15°C; 1013mbar)
Consumption (15°C; 1013mbar)
Gas Cock Outlet Pressure
min - max
mm
mc/h
Kg/h
1.,25
2.72
----
0.72
----
2.02
0.72
----
2.02
mbar
11.4- 2.0
27.5 (*) - 5.2
35.0 (*) - 7.0
A/27 MFFI
Main Burner: n. 15 jets (ø)
Consumption (15°C; 1013mbar)
Consumption (15°C; 1013mbar)
Gas Cock Outlet Pressure:
max - min
1.25
3.16
----
0.72
----
2.35
0.72
----
2.32
mc/h
Kg/h
mbar
11.6-2.2
(*) - 4.8
(*) - 6.0
(1mbar = 10,197 column of water)
The outlet pressure of the gas cock is obtained by completely loosening the
screw on the solenoid. The maximum pressure of the gas to the burner will be
equal to the nominal delivery pressure minus the head loss within the gas
valve.
B023
21
The boiler can be converted to use either methane (natural) gas (G20) or
LPG (G30 - G31) by an Authorised Service Centre.
The operations that must be performed are the following:
1. Replace the jets on the main burner (see table in section 4);
2. Adjust the maximum and minimum thermal capacity values for the boiler
(see table in section 4);
4.1
Changing the Type of
Gas
3. Replace the gas rating plate;
4. Adjust the maximum thermal power setting;
CATEGORY II2H3+
Methane Gas
G20
Liquid Butane Gas
G30
Liquid Propane Gas
G31
Recommended Soft-Light Pressure
(mbar)
5-5.5
17 - 18
18 - 19
5. Adjust the soft-light feature;
6. Adjust the ignition delay feature for the heating system (can be set from
0 to 2 mins.).
It is recommended that the following checks be made on the boiler at
least once a year:
5.
MAINTENANCE
1 - Check the seals for the water connections; replacement of any faulty seals.
2 - Check the gas seals; replacement of any faulty gas seals.
3 - Visual check of the entire unit.
4 - Visual check of the combustion process and cleaning of the burners if
needed.
5 - If called for by check no. 3, dismantling and cleaning of the combustion
chamber.
6 - If called for by check no. 4, dismantling and cleaning of the injectors.
7 - Visual check of the primary heat exchanger:
- check for overheating in the blade assembly;
- clean the exhaust fan if needed.
8 - Adjustment of the flow rate of the gas: flow rate for lighting, partial load and
full load.
9 -Check of the heating safety systems:
-safety device for maximum temperature;
-safety device for maximum pressure.
10 -Check of the gas safety systems:
-safety device for lack of gas or flame (detection electrode);
-safety device for gas cock.
11 -Check of the electrical connection (make sure it complies with the
instructions in the manual).
12 -Check of domestic hot water production efficiency (delivery rate and tem-
perature)
13 -Check of the general performance of the unit.
14 -General check of the discharge/ventilation of the combustion by-
products.
B023
22
6.
MISCELLANEOUS
6.1
Wiring Diagram for
Two Heating Zones
BROWN
BLUE
5
2
BOILER ELECTRICAL SUPPLY CABLE
GREY
9
ORANGE
Remove internal time clock plug
from the the P.C.B. then connect
room stat terminal block on the
reverse of the boiler control panel
(see section 2.10) to 9 + 10 on
the junction box.
10
3
GREEN/YELLOW
V4043H
VALVE
TYPICAL
JUNCTION BOX
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
1
3
2
4
5
2
T6360B
ROOM
THERMOSTAT
ZONE1
BROWN
BLUE
8
2
9
GREY
ORANGE
10
3
GREEN/YELLOW
V4043H
VALVE
1
3
2
6
8
2
T6360B
ROOM
THERMOSTAT
ZONE 2
L
N
E
1
2
3
If a room thermostat is not requiedonZone1,insertalink
between 4 + 5 on the junction box.
If a room thermostat is not requiedonZone2,insertalink
between 6 + 8 on the junction box.
240V
MAINS INPUT (3 AMP)
B023
23
6.2
Wiring Diagram for
Connection to Ariston
Unvented Cylinder
1
3
2
4
5
2
BOILER ELECTRICAL SUPPLY CABLE
Remove internal time clock plug
T6360B
ROOM
from the the P.C.B. then connect
TYPICAL
JUNCTION BOX
room stat terminal block on the
reverse of the boiler control panel
(see section 2.10) to 9 + 10 on
the junction box.
THERMOSTAT
BROWN
BLUE
5
2
9
• 1
GREY
ORANGE
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
10
3
GREEN/YELLOW
V4043H
HEATING VALVE
BROWN
8
2
BLUE
GREY
9
ORANGE
10
3
GREEN/YELLOW
V4043H
HOT WATER VALVE
L
1
2
3
N
E
240V
MAINS INPUT (3 AMP)
Cylinder
thermostat
1
8
6
1
Thermal
C/P
cut-out
P
1 C/P
2
2
Not
used
B023
24
NOTES
B023
25
NOTES
B023
26
B023
27
Manufacturer:
Merloni TermoSanitari SpA - Italy
Commercial subsidiary: MTS (GB) LIMITED
MTS Building
Hughenden Avenue,
High Wycombe
Bucks HP13 5FT
Telephone: (01494) 755600 -
39846012
Fax: (01494) 459775
Technical Service Hotline: (01494) 539579
Cod.
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