Ariston microGENUS 23 MFFI User manual

Installation
Instructions
Type C Boilers
G.C.N: 47-116-14
47-116-15
LEAVE THESE INSTRUCTIONS
WITH THE END-USER
Country of destination: GB

2
TABLE OF CONTENTS 1. GENERAL INFORMATION
1.1 GENERAL INSTRUCTIONS
1.2 OVERALL VIEW
2. INSTALLATION
2.1 REFERENCE STANDARDS
2.2 SITING THE APPLIANCE
2.3 OVERALL DIMENSIONS
2.4 CLEARANCES
2.5 MOUNTING THE APPLIANCE
2.6 ELECTRICAL CONNECTION
2.7 GAS CONNECTION
2.8 WATER CONNECTIONS
2.9 FLUE CONNECTION
2.10 ROOM THERMOSTAT CONNECTION
2.11 ELECTRICAL/SYSTEM DIAGRAMS
2.12 WATER CIRCUIT DIAGRAMS
3. COMMISSIONING
3.1 INITIAL PREPARATION
3.2 CONTROL PANEL
3.3 REMOVING THE FRONT PANEL
3.4 INITIAL START UP
3.5 OPERATIONAL ADJUSTMENTS
3.6 COMBUSTION ANALYSIS
3.7 FUME DISCHARGE MONITORING
3.8 BOILER SAFETY SYSTEMS
3.9 DRAINING THE SYSTEM
4. GAS ADJUSTMENTS
GAS ADJUSTMENT TABLE
4.1 CHANGING THE TYPE OF GAS
5. MAINTENANCE
6. MISCELLANEOUS
6.1 WIRING DIAGRAM FOR TWO HEATING ZONES
6.2 WIRING DIAGRAM FOR CONNECTION TO AN ARISTON UNVENTED CYLINDER
7. TECHNICAL INFORMATION

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.
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.
Read the instructions and recommendations in these Installation Instructions
carefully to ensure proper installation, use and maintenance of the appliance.
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 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 or analysis of combustion by-
products (see section 3.6) and cleaning of the burner if needed.
1. GENERAL
INFORMATION
3
1.1 GENERAL INSTRUCTIONS
CO034A

4
5 - If called for by point.3, dismantling and cleaning of the combustion
chamber.
6 - If called for by point.4, dismantling and cleaning of the burner jets.
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 ionisation (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 (flow rate and temperature)
13- General check of the combustion by-products of the discharge/ventilation
system.
14- Check of the general performance of the unit.
LEGEND:
1. Flue connector
2. Air intake for twin pipe flue systems
3. Fan
4. Combustion chamber hood
5. Main heat exchanger
6. Safety thermostat
7. Combustion chamber
8. Combustion chamber insulation panel
9. Burner
10. Detection electrode
11. Ignition electrodes
12. Motorised diverter valve
13. Main circuit temperature probe
14. Main circuit flow switch
15. Domestic hot water temperature probe
16. Gas valve
17. Spark generator
18. Domestic hot water flow switch
19. Domestic cold water inlet filter
20. Secondary heat exchanger
21. Circulation pump with automatic air release valve
22. Safety valve (3 bar)
23. Expansion vessel
24. Air pressure switch
25. Combustion analysis intakes
1.2 OVERALL VIEW
FIG. 1.0
IN013A

5
The technical information and instructions provided herein below are
intended for the installer so that the unit may be installed correctly and
safely.
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 .
This appliance must be installed by a competent installer in
accordance with current Gas Safety (installation & use)
Regulations.
The installation of this appliance must be in accordance with the relevant
requirements of the current 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:
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.
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 the
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.
2.1 REFERENCE STANDARDS
2. INSTALLATION
Low pressure
pipes BS 6891 1988
Boilers of rated input
not exceeding 60 kW BS 6798 1987
Forced circulation hot
water system BS 5449 1990
Installation of gas hot water
supplies for domestic purposes
( 2nd family gases) BS 5546 1990
Flues BS 5440-1 1990
Air supply BS 5440-2 1989
2.2 SITING THE APPLIANCE

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 information table section in 6, 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)
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 “”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
6
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.
2.7 ELECTRICAL CONNECTION
2.5 MOUNTING THE APPLIANCE
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”)
2.3 OVERALL DIMENSIONS
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 FIG. 2.2
2.4 CLEARANCES
FIG. 2.1
FIG. 2.2
FIG. 2.3
QT002A
DM004A
VR001A

VIEW OF THE BOILER CONNECTIONS
LEGEND:
A = Central Heating Flow
B = Domestic Hot Water Outlet
C = Gas Inlet
D = Domestic Cold Water Inlet
E = Central Heating Return
F = 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.
2.9 WATER CONNECTIONS
2.8 GAS CONNECTION 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.
Pipe work must be of an adequate size. Pipes of a smaller size than the
boiler inlet connection should not be used.
7
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 Genus 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.
FIG. 2.4
FIG. 2.5 KT002A
SC008A

8
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 downward 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 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 6 l (1.3 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
VR003A

Ø60/100 mm
FIG. 2.7
A
BC
D
E
F
G
J
K
HI
L
GF
The boiler is designed to be connected to a coaxial flue discharge system.
9
2.9 FLUE CONNECTIONS FLUE SYSTEM
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
KentTN9 1RA
The minimum acceptable spacing from the terminal to obstructions and
ventilation openings are specified in FIG. 2.6.
T ERMINAL P OSTION mm
A - Directly below an open window or other opening 300
B - Below gutters, solid pipes or drain pipes 75
C - Below eaves 200
D - Below balconies or car-port roof 200
E - From vertical drain pipes and soil pipes 75
F - From internal or external corners 300
G - Above ground or below balcony level 300
H - From a surface facing a terminal 600
I - From a terminal facing a terminal 1200
J - From an opening in the car port
(e.g.door, window) into dwelling 1200
K - Vertically from a terminal in the same wall 1500
L - Horizontally from a terminal in the same wall 300
FIG. 2.6 FU010A
FU025A
FU002A

Ø80 mm
The components marked * in FIG 2.9 are present or absent
depending on the type of flue system used by the installer.
In addition, it is also possible to use a split (twin pipe)
system by fitting a special adaptor to the flue connector
and using the aperture for the air vent intake located on
the top part of the combustion chamber.
To utilise the air intake it is necessary to:
1. Remove the bottom of the air intake by cutting it with a
suitable knife (see FIG.2.8);
2. Insert the elbow into the air intake until it reaches the
lower end.(There is no need to use gaskets or sealing
componds).
10
IMPORTANT!
For all flue systems, a restrictor
must always be inserted into the
boiler’s flue connector; the
restrictor must be ø43 or ø41 in
diameter depending on the length
of piping indicated inTable 2.1.
The diagrams illustrate some of the
various designs for coaxial or twin
pipe flue systems.
For further information on
discharge/ventilation accessories,
see the FLUE PIPE ACCESSORIES
MANUAL.
COAXIAL SYSTEMS
FIG. 2.8
FIG. 2.9
FIG. 2.10
FU05A
FU004A FU006A
FU001A

Exhaust
Type
C12 (xy)
C32 (xy)
C42 (xy)
C52 (xy)
C82 (xy)
Restrictor
ø43 mm
L max = 11.5 m
L max = 11,4 m
Maximum
Extension
Exhaust/Air
43 m
43 m
43 m
40 m
NO
Restrictor
L min = 11.5 m
L max = 43 m
L min = 11,4 m
L max = 40m
Risk of Condensation Forming
Twin Pipe
Systems
ø80/80
Piping not insulated
ø43 restrictor NO
4.3 m 6.9 m
4.3 m 6.9 m
Piping insulated
ø43 restrictor NO
NONE NONE
5,7 m 21,7 m
L = Sum of the total length of exhaust + air intake piping.
11
Exhaust
Type
C12 (xx)
C32 (xx)
C42 (xx)
Restrictor
ø43 mm
L min = 0.5 m
L max = 2 m
Maximum
Extension
Exhaust/Air
L = 4 m
NO
Restrictor
L min = 2 m
L max = 4 m
Risk of Condensation Forming
Coaxial
Systems
ø60/100
Piping not insulated
ø43 restrictor NO
NONE NONE
Piping insulated
ø43 restrictor NO
NONE NONE
TABLE 2.1
Exhaust
Type
C12 (xy)
C32 (xy)
C42 (xy)
C52 (xy)
C82 (xy)
Restrictor
ø41 mm
L max = 38 m
L max = 34 m
Maximum
Extension
Exhaust/Air
62 m
62 m
62 m
54 m
NO Restrictor
L min = 38 m
L max = 62 m
L min = 34 m
L max = 54 m
Risk of Condensation Forming
Twin Pipe
Systems
ø80/80
Piping not insulated
ø41 restrictor NO restrictor
8 m 11 m
8 m 11 m
Piping insulated
ø41 restrictor NO restrictor
19 m 31 m
19 m 31 m
Exhaust
Type
C12 (xx)
C32 (xx)
C42 (xx)
Restrictor
ø41 mm
L min = 0.5 m
L max = 1 m
Maximum
Extension
Exhaust/Air
L = 4 m
NO Restrictor
L min = 1 m
L max = 4 m
Risk of Condensation Forming
Coaxial
Systems
ø60/100
Piping not insulated
ø41 restrictor NO restrictor
NONE NONE
Piping insulated
ø41 restrictor NO restrictor
NONE NONE
27 MFFI
23 MFFI

12
To connect a room thermostat, it is necessary to:
1. - Open the control panel as indicated in section 3.3.
2.- Remove the link “A”from the terminal block on the reverse of the control panel.
3. - Insert the thermostat cable through the cable grommet and fasten it by means of the
cable-clamp provided.
4. - Then connect the thermostat wires to the terminal block.
5.- If a remote time clock is to be fitted, disconnect the integral time clock from the P.C.B.
6. - Using a volt-free switching time clock, connect the switching wires from the time clock
following points 1-4 above.
7.- If using an external time clock and room thermostat, these must be connected in
series as points 1-7 above.
Note: Only a two-wire type room thermostat can be used.
An anti-frost device is built-in to the appliance’s electronic regulation
system.
2.10 ROOM THERMOSTAT
CONNECTION
A
TWIN PIPE
SYSTEMS
FIG. 2.11
In calculating the lengths of the pipes, the
maximum length “L”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 exhaust/ air intake pipes must
have the same diameter of ø80 mm.
2 - If elbows are to be inserted into the
air intake and/or exhaust system, the
calculation of the overall length must
take into consideration the values for
each elbow, see the FLUE PIPE
ACCESSORIES MANUAL.
3 - The exhaust pipe must protrude by at
least 0.5 m above the top of the roof
in the event that it is located on the
opposite side to the side with the air
intake (this condition is not obligatory
when the air intake and exhaust are
located on the same side of the
building).
FU007A
Fo016A Fo017A

JK
Blk Blk Gry Gry Pnk Pnk Pnk Gry Gry
Wh Wh Wh Wh Wh Wh Wh
Rd/Blk Rd/Blk
Rd/Blk
Blk Blk Blk Brn Brn Brn Brn Blk Blk
2.12 ELECTRICAL DIAGRAM
13
LEGEND:
A = Time Clock Connector
B = Central Heating Selection (Winter) and
Temperature Adjustment
C = Connector for Total Check System
D = Domestic Hot Water Temperature Adjustment
E = Soft-light Adjustment
F = Maximum Heating Adjustment
G = On/Off Switch
H = On/Off L.E.D.
I = Fume Sensor L.E.D.
J = Ignition Failure (Lockout) L.E.D.
K = Low System Water Level/Lack of Circulation L.E.D.
L = Reset Button
M = Economy/Comfort Selector
N = Overheat L.E.D.
O = Temperature L.E.D.s
P = Transformer
Q = Circulation Pump Relay
R = Fan Relay
S = Gas Valve Relay
T = Motorised Diverter Valve Relay
V = Spark Generator
U = Anti-cycling Device Adjustment for Heating
A01 = Circulation Pump
A02 = Fan
A03 = Spark Generator/Gas Valve Supply
A04 = Motorised Diverter Valve
A05 = Flame Detection Circuit
A06 = Detection Electrode
A07 = Main Circuit Temperature Probe
A08 = Domestic Hot Water Temperature Probe
A09 = Domestic Hot Water Flow Switch
A10 = Main Circuit Flow Switch
A11 = Modulator
A12 = Air Pressure Switch
A13 = Safety Thermostat
A14 = External (Room) Thermostat
Colours:
Gry = Grey
Wh = White
Pnk = Pink
Brn = Brown
Bl = Blue
Blk = Black
Rd/Blk = Red/Black
FIG. 2.12 SE017A

14
LEGEND:
1. Fan
2. Main Heat Exchanger
3. Overheat Thermostat
4. Burner
5. Ignition Electrodes
6. Detection Electrode
7. Motorised Valve
8. Main Circuit Temperature Probe
9. Main Circuit Flow Switch
10. Automatic By-pass
11. Domestic Hot Water Temperature Probe
12. Secondary Heat Exchanger
13. Gas Valve
14. Domestic Hot Water Flow Switch
15. Domestic Water Inlet Filter
16. Pressure Gauge
17. Safety Valve
18. Circulation Pump with Automatic
Air Release Valve
19. Expansion Vessel
20. Air Pressure Switch
A. Central Heating Flow
B. Domestic Hot Water Outlet
C. Inlet Gas
D. Domestic Cold Water Inlet
E. Central Heating Return
2.13 WATER CIRCUIT DIAGRAM
FIG. 2.14
UJ
K
M
L
R
SQT
ON
FIG. 2.13
SF014A
SI017A

15
MTS (GB) Limited support the initiative.Within the information pack
you will find a copy of the logbook. It is important that this is
completed in the presence of your customer, they are shown how to us it,
and it is signed by them. Please instruct your customer that they must have
their logbook with them whenever they contact a service engineer
or us.
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.
FILLING THE HEATING SYSTEM:
Remove the panels of the case and lower the control panel (see section
3.3 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
system (section 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 the 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.
3. COMMISSIONING
3.1 INITIAL PREPARATION

In order to access the inside of the boiler, it is necessary to unscrew
the fastening screws “A”of the control panel located on the lower part
of the panel itself.
The control panel moves downward and when pulled forward rotates
on two lateral hinges.
The panel stays in a semi-horizontal position, which allows access to
the inner parts of the boiler.
In order to increase the maneuvering space, it is possible to raise the
control panel and rotate it to a fully horizontal position.
16
3.3 REMOVING THE
FRONT PANEL
B
1
2
3
4
5
A
LEGEND:
A - On/Off knob
B - Domestic hot water temperature adjustment knob
C - Central heating selection (winter) and temperature
adjustment knob
D - On/Off L.E.D. (green)
E - Fume sensor L.E.D.(yellow)
F - Ignition failure (lockout) L.E.D. (red)
G-“Economy/Comfort”mode selection knob
H - Ignition failure (lockout) and/or overheat reset button
I - Overheat L.E.D. (red)
J - Low system water level L.E.D. (red)
K - Central heating temperature L.E.D (yellow)
L - Time clock
M - Heating system pressure gauge
3.2 CONTROL PANEL
FIG. 3.1
To dismantle the front
casing panel it is necessary
to:
1 - Remove the two screws
“B”;
2 - Lift the front casing panel
up and forward.
FR025A
FO006A
FO008A
FO009A
FO012A
FO013A

17
3.4. INITIAL START-UP
(See section 3.2 for references) it is possible to:
- Set the temperature of the heating system by adjusting the knob “C”
- Set the temperature of the domestic hot water by turning knob “B”
- The selector knob “G”allows the user to choose the economy mode
(position “E”) or the comfort mode (position “C”).
The economy mode is the normal state for the operation of the boiler,
since the domestic water is heated up only when a tap is turned on.
The comfort mode is a special operating state, because the water
contained in the secondary exchanger and in the primary exchanger is
kept in a preheated condition, thereby allowing a quicker delivery of
domestic water when required. The latter is therefore the more
convenient choice.
To access the areas in which adjustments are made, it is necessary to open
the control panel, as indicated in section 3.3, then remove the rear
inspection cover by unscrewing the two screws. Access is thereby provided
to the P.C.B.and to the following components:
1. the power supply cable connector;
2. the fuses;
3. the soft-light potentiometer the setting for which can range from the
minimum thermal power to the maximum;
4. the maximum thermal heating power potentiometer adjustable by the
minimum to maximum power (already calibrated in the factory to 70% of
the maximum thermal power);
5. the potentiometer for adjusting the ignition delay (anti-cycling) feature,
which can be set from 0 to 2 minutes (set in the factory at one minute);
6. the time clock connector.
THE CHECKS TO BE RUN BEFORE INITIAL START-UP ARE AS FOLLOWS:
1. Make sure that:
-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
appropriate 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 turning the On/Off switch “A”(see FIG.3.1)
- the L.E.D. “D”will illuminate - turn the selector knob “C”to the winter
/central heating position. This will start the circulation pump. After 7
seconds, the boiler will signal a shutdown due to ignition failure. 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).
3.5 OPERATIONAL
ADJUSTMENTS

The boiler is fitted with the following devices (see section 3.2 for references).
1 - IGNITION FAILURE:
This control signals an ignition failure on the burner 7 seconds after a
lighting failure. The L.E.D. “F”will illuminate to signal the shutdown
status.
The system can be reset by pressing and releasing the button “H”after
checking to make sure that the gas cock is open.
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; the circulation pump comes to a
halt and the red L.E.D. “J”illuminates.
The system may be reset, after re-establishing the correct level of
pressure in the boiler, turning the “A”knob.
3 - OVERHEATING:
This control shuts off the boiler in the case where the primary circuit
reaches a temperature in excess of 105°C.
The red L.E.D.s “I”and “F”will illuminate to signal this shutdown
status.
The system can be reset by waiting a few minutes for the primary
exchanger to cool down and then by pressing and releasing the “H”
button.
4. LIMESCALE BUILD-UP:
The boiler is equipped with a device that limits the formation of
Limescale in the secondary exchanger by controlling the temperature of
the domestic hot water (max 61°C) and also controlling the temperature
of the water in the primary heating circuit.
18
3.8 BOILER SAFETY SYSTEMS
In the boiler, it is possible to monitor the correct operation of
the flue exhaust/air intake, checking for a loss of general
pressure in the system. Through the use of a differential
manometer connected to the test points of the combustion
chamber, it is possible to detect the ∆P of operation of the air
pressure switch.
The value detected should not be less than 0,55 mbar for
23kW and 0.75 mbar for 27kW under conditions of maximum
thermal power in order for the boiler to function properly and
without interruption.
The flue connector has two apertures, readings can be
taken for the temperature of the combustion by-products
and of the combustion air, as well as of the concentrations
of O2and CO2, etc. .
To access these intakes it is necessary to unscrew the front
screw and remove the metal plate with sealing gasket.
The best test conditions, with the maximum heating power,
are achieved by turning the selector knob “C”to the “max”
position and removing the electrical connection to the heating
sensor (see section 6.).
3.6 COMBUSTION ANALYSIS
3.7 FUME DISCHARGE
MONITORING
FU008A
FU009A

19
DRAINING THE HEATING SYSTEM
The heating system must be emptied as follows:
- 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).
3.9 DRAINING THE SYSTEM
5. ANTI-FROST DEVICE:
The boiler is equipped with a device that, in the event of the water
temperature going below 5°C, the 3-way diverter valve switches to
domestic hot water and the burner ignites at the minimum power until
the boiler water reaches a temperature of about 50°C.
This device operates only if the boiler is functioning perfectly and:
- the system pressure is sufficient;
- the boiler is powered electrically;
- the gas is distributed.
6 - EXHAUST DISCHARGE ANOMALY SHUTDOWN:
The boiler is fitted with safety devices, which in the event of defective
discharge of exhaust fumes, automatically interrupts the gas supply,
thereby shutting off the boiler.
The shutdown of the boiler is temporary and is indicated by the
illumination of the yellow L.E.D. “E”for a period of about 15 minutes.
Once this time period has passed and the discharge state of exhaust
fumes has returned to normal, the boiler automatically turns back on.
7 - SAFETY SHUTDOWN:
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.

20
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);
3. Replace the gas rating plate;
4. Adjust the maximum thermal power setting;
5. Adjust the soft-light feature;
6. Adjust the ignition delay feature for the heating system (can be set from 0
to 2 mins.).
CATEGORY II2H3+
Recommended Soft-
light Pressure
(mbar)
Methane
Gas
G20
8.0
Liquid
Propane
Gas
G31
16.0
Liquid
Butane
Gas
G30
16.0
4.1 CHANGING THE
TYPE OF GAS
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.
[1 mbar = 10,197 mmc.a.]
4. GAS ADJUSTMENTS
Lower Wobbe Index (15°C;1013mbar) MJ/m3h
Nominal Delivery Pressure mbar
Minimum Delivery Pressure mbar
23 MFFI
Main Burner: n. 13 jets (ø)mm
Consumption (15°C; 1013mbar) mc/h
Consumption (15°C; 1013mbar) Kg/h
Gas Cock Outlet Pressure
max - min mbar
27 MFFI
Main Burner: n.15 jets (ø)
Consumption (15°C; 1013mbar) mc/h
Consumption (15°C; 1013mbar) Kg/h
Gas Cock Outlet Pressure:
max - min mbar
CATEGORY II2H3+ Methane Gas
G20 Liquid Butane Gas
G30 Liquid Propane Gas G31
45.67
20
17
1.30
2.72
----
11.0 - 2.0
1.30
3.15
----
11.0 - 1.6
80.58
29
20
0.77
----
2.02
(*) - 6.0
0.77
----
2.34
(*) - 4.6
80.58
37
25
0.77
----
2.02
(*) - 6.0
0.77
----
2.31
(*) - 6.0