Beretta Ciao C.A.I User manual

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CiaoC.A.I. - C.S.I.
Service Manual
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1 GENERAL
1.1 GENERAL INSTRUCTIONS
Make sure the supplied goods are intact and comple-
te after unpacking them and contact the boiler sales
point if there are any problems of nonconformity.
The boiler must be installed by BERETTA Servicing
Centre.
The boiler must be used for the purpose for which the
factory expressly designed it. The factory shall not be
held liable either contractually or non-contractually
for damages caused to persons, animals or objects,
caused by erroneous installation, regulation,
maintenance and improper use.
Should any water leak out, turn off the water supply
and contact BERETTA Servicing Centre.
Regularly check that the water system working
pressure is between 1 and 1.5 bar, if not, contact
BERETTA Servicing Centre.
The following operations should at least be done if the
boiler is not going to be used for a long time:
- Turn the main switch of the appliance and the general
switch of the system to “off”
- Turn off the fuel and water taps of the heating system
- Empty out the heating and sanitary systems if there is
any risk of freezing.
The boiler should be overhauled at least once a year.
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1.2 BASIC RULES FOR SAFETY
We would remind you that some basic rules for safety must
be followed with products using combustible substances,
electricity and water such.
Childrenandunassisteddisabledpersonsareforbidden
to use the boiler.
It is forbidden to work with devices or electrical
appliances such as switches, domestic appliances etc.
if there is a smell of fuel or unburned fuel.
In this is the case:
- Air the room by opening doors and windows
- Switch off the fuel on/off switch
It is forbidden to touch the boiler with bare feet or if
some parts of the body are wet.
No cleaning operations must be done before
disconnecting the boiler from the main electricity
supply, turning the main system switch to “off”.
It is forbidden to modify the safety or control devices
without permission and instructions from the boiler
manufacturers.
It is forbidden to tug, pull out and twist wiring coming
out of the boiler even if the latter is disconnected from
the main electricity supply.
It is forbidden to seal up or reduce the size of vents in
the installation premises, if existing. Vents are
indispensable for correct combustion and for safety.
It is forbidden to leave inflammable containers and
substancesinthepremises wheretheboiler is installed.
It is forbidden to expose the boiler to atmospheric
agents. It has not been designed for the open air and
does not have adequate anti-freeze systems.
It is forbidden to discard or leave packing material
within the reach of children, as it could be a potential
source of danger.
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1.3 GENERAL GUARANTEECONDICTIONS
The guarantee covers all the parts making up the products. It
covers repairs and eventually replacing any of the parts that the
supplier considers as having production defects, free of charge.
A qualified authorized person should ignite the boiler the first
time and then make out a certificate, signed for acceptance by
the customer.
The guarantee shall terminate if:
- the cause of defect has nothing to do with the product itself;
- non-original components, spare parts or wear materials have
been used;
- repair and servicing work has been done by non-authorized
persons;
- environmental or installation conditions differ from those
specified in section 7 page 71.
The guarantee does not cover quick wearing materials: filters,
gaskets, dials, etc.
1.4 IDENTIFICATION OF BOILER MODEL
Boilers can be identified through the Serial number plate:
Showing technical data and working characteristics.
Badhandling,removal,missingserialnumberplates
orany other preventingreliable identification ofthe
product,complicatesanyinstallationormaintenance
operation.
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Fig. 1.1

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1.5 IDENTIFICATION OF MAIN
COMPONENTS
(APPENDIX - A page 77)
INDEX
• Burner page 3
• Combustion chamber page 3
• Circulator page 3
• Igniter/control electrode page 4
• Flowmeter page 4
• Flow limiter page 4
• Water pressure switch page 4
• Safety pressure switch (C.S.I. only) page 4
• Filling tap page 5
• Bithermal exchanger page 5
• Air box (C.S.I. only) page 5
• Electronic control panel page 5
• NTC temperature control probes page 6
• Fumes thermostat (C.A.I. only) page 6
• Limit thermostat page 6
• By-pass valve page 6
• Gas valve page 6
• Safety valve page 7
• Expansion tank page 7
• Fan (C.S.I. only) page 7
• Venturi and Pitot tube page 7
1.5.1 Burner
(POS. 1 APPENDIX - A page 77)
The burner is installed underneath the combustion chamber
(Sect. 1.5.2 page 3) and serves to create the correct mixture of
air and gas for the combustion process.
Itconsists ofa series ofperforated rampsin stainlesssteel, linked
together and adequately spaced one from the other.
The gas flowing from the valve (Sect. 1.5.17 page 6) enters the
burner Venturi and mixes with primary air; the mixture then
comes out of the numerous openings made on the upper parts
of the ramps and ignites, thanks to the secondary air sucked
into the combustion chamber.
1.5.2 Combustion chamber
(POS. 2 APPENDIX - A page 77)
The combustion chamber is located at the centre of the boiler
and combustion occurs inside it.
It consists of a steel plate structure adequately folded to be
able to insert slabs of insulating material made of ceramic
fibre with normal working temperature of about 1200°C
and a melting point of about 1700°C.
1.5.3 Circulator
(POS. 3 APPENDIX - A page 77)
The circulator is installed on the return side of the boiler
water circuit and it facilitates the water circulation while
heating is on when the room thermostat signals a drop in heat.
The circulator is made of composite material with incorporated
degasser.
The current must be higher than that of the main power supply
at ignition to push the water into the central heating system;
this is why it is necessary for the condenser discharge to be
housed inside the connector box.
Water in the pump is circulated and pushed towards the
bi-thermal exchanger (Sect. 1.5.10 page 5) by the blades.
At the same time a vacuum is created inside the pump,
sucking other water from the system and triggering off the
circulation of primary fluid.
Fig. 1.2
Fig. 1.3
Fig. 1.4
Automatic air
vent bottle
Connection cover

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Ball cock
Filter
Segments
1.5.4 Igniter/control electrode
(POS. 4 APPENDIX - A page 77)
The electrodeis located near the centre rampof theburner(Sect.
1.5.1 page 3) and its job is to strike up the spark for ignition and
to control the presence of the flame.
The igniter plug consists of a metallic core and is coated on the
outside with ceramic material for electric insulation. The end
of the metal part is free from ceramic insulation and is located
at about 3 mm from the burner.
1.5.5 Flowmeter
(POS. 5 APPENDIX - A page 77)
The flowmeter is connected to the inlet on the sanitary side
of the boiler; the device is designed to control the water flow
with a ball cock consisting of a teflon spear valve, with a
magnetized sector on the upper part.
The ball cock is in stand-by position at the initial phase and the
internalcontactis open.Itrisesas thewaterflowsthrough making
thetwosegmentscometogether,theflowmetercontact thencloses
releasing electricity to the water in the boiler.
There is a filter at the cold water inlet to save the flowmeter
from passing impurities.
1.5.6 Flow limiter
The flow limiter is located at the inlet of sanitary water on the
bi-thermal exchanger (Sect. 1.5.10 page 5) and has the work
of reducing the sanitary water level to a maximum value of
101/min.
1.5.7 Water pressure switch
(POS. 6 APPENDIX - A page 77)
The water pressure switch is located on the right hand side of
the water heating unit; it is a device for controlling whether
there is a pressure or not in the primary system. Operating levels
are:
- ON system pressure > 0.45 bar;
- OFF system pressure < 0.45 bar.
1.5.8 Safety pressure switch (C.S.I only.)
(POS. 7 APPENDIX - A page 77)
The safety pressure switch is located on the upper part of
the air box (Sect. 1.5.11 page 5) and controls that the fan
(Sect. 1.5.20 page 7) and flues are working properly.
It consists of a double shell containing a silicone rubber
membrane. The membrane works a microswitch when the
difference in pressure indicated by the Venturi and the Pitot
tube (Sect. 1.5.21 page 7) falls to below the safety limit,
blocking the gas supply.
Fig. 1.5
Fig. 1.6
Fig. 1.7
Fig. 1.8
Fig. 1.9

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Compensating
outlet
Analysis
of outlets
Primary
water
flowing
Secondary
water
flowing
Turbo propeller
1.5.9 Filling tap
(POS. 8 APPENDIX - A page 77)
The filling tap is located at the sanitary inlet in the boiler and
hasthe job of connecting up the sanitarysystem withthe heating
system for filling or topping up (Sect. 7.4 page 72) .
1.5.10 Bi-thermal exchanger
(POS. 9 APPENDIX - A page 77)
The bi-thermal exchanger is located on the upper part of the
combustion chamber (Sect. 1.5.2 page 3) and is the part used
by the primary water (heating) and secondary (sanitary) water
for heating up by effect of heat generated in combustion.
It consists of a coil with two oval shaped tubes, one inside
the other, all fitted inside a commutator core which is
designed to increase the area of heat exchange. The entire
exchanger is coated with aluminium alloy to protect it from
corrosion.
The outside part of the coil is reserved for the flow of primary
fluid, flowing against the current of the secondary fluid.
The inside part is reserved for the flow of secondary water;
the coil has septum inside - turbo propeller - to increase
performance and to avoid temperature stratification.
1.5.11 Air box ( C.S.I. only)
(POS. 10 APPENDIX - A page 77)
The air box is at the centre of the boiler and serves to isolate all
components involved in the combustion process (burner,
combustion chamber, electrode, safety pressure switch,
exchanger and fan) from the domestic environment.
It is made up of four units in aluminised metal sheets with
neoprene sealing.
There is a compensation outlet connected to the gas valve
pressure regulator, at the bottom of the box. The outlet stabilizes
the membrane inside the regulator through a small tube.
The air box is designed to be able to analyse combustion
parameters without having to remove the case.
Measurements are taken through two pockets located on
the upper part, which are used to house probes for measuring
air temperature andpolluting fumes are inserted, after
removing the screw caps.
1.5.12 Electronic control panel
(POS. 11 APPENDIX - A page 77)
The electronic control panel is housed inside the control panel
and is designed to control the entire appliance.
It contains terminals for connecting up the boiler electrically
and for connecting a eventualy room thermostat (Sect. 7.3
page 71).
Fig. 1.10
Fig. 1.11 Fig. 1.13
Fig. 1.12

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1.5.13 NTC temperature control probes
(POS. 12 APPENDIX - A page 77)
NTC probes, Negative Temperature Control, are located at the
exchanger outlet (Sect. 1.5.10 page 5) on the heating side and
on the outlet ramp of the exchanger on the sanitary side
respectively; they measure the temperature of primary and
secondary water for the electronic control panel.
These are thermistors where the value of the heating element
drops as the temperature rises.
The instantaneous comparison between effective temperature of
the water and the one set by the User causes a change in the
current sent to the gas valve modulator coil (Sect. 1.5.10 page 5).
1.5.14 Fumes thermostat (C.A.I. only)
(POS. 13 APPENDIX - A page 77)
The fumes thermostat is located on the upper right hand side of
the hood; it is a device for controlling correct evacuation of
combustion products.
Combustion products will be discharged through slits on the
side of the hood if the flue should be obstructed, heating up the
thermostat so that it starts working.
1.5.15 Limit thermostat
(POS. 14 APPENDIX - A page 77)
The limit thermostat is on the heating side of the exchanger
(Sect. 1.5.10 page 5) and serves to prevent the boiler from
boiling.
It is an automatically set contact device, which will interrupt
the flame detection electrical circuit, should it work at a
temperature of about 110°C.
1.5.16 By-pass valve
The automatic by-pass is installed inside the duct
connecting the system’s delivery to CH return. Its job is to
guarantee primary water re-circulation in the boiler in
systems with high load loss.
The spring inside the by-pass valve is gauged to 530 gr. This
should be replaced with another one with increased capacity
if a high-headed circulator is used.
1.5.17 Gas valve
(POS. 15 APPENDIX - A page 77)
The gas valve is located under the combustion chamber (Sect.
1.5.2 page 3) and is the part designed to supervise burner
ignition, regulation and control operations.
The valve is made up of an aluminium pressofusion with two
solenoid valves, mechanically in series but parallel electrically.
The modulator is an integral part of the gas valve; the operator
modulates by changing the current to the coil to let the right
quantity of gas to flow to the burner. These configuration ensure
Fig. 1.14
Fig. 1.15
Fig. 1.16
Fig. 1.17
Heating
sensor
Sanitary
sensor
0 20 40 60 80 100
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
22000
24000
26000
28000
30000
32000
34000
0
RESISTANCE (ohm)
NOMINAL RESISTANCE
MINIMUM RESISTANCE
MAXIMUM RESISTANCE
TEMPERATURE (°C)

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Solenoid valves
Modulator
that gas flowing to the burner is stopped very quickly under
any faulty condition.
The modulator is an integral part of the gas valve; the operator
modulates by changing the current to the coil to let the right
quantity of gas to flow to the burner (Sect. 1.5.1 page 3).
1.5.18 Safety valve
(POS. 16 APPENDIX - A page 77)
The safety valve is located underneath the circulator (Sect. 1.5.3
page 3) and has the job of protecting water circulation from
eventual over pressure caused, for example, by an increase in
the volume of primary fluid due to heating effect. The valve is
gauged to an operating pressure of 3 bar.
1.5.19 Expansion tank (POS. 17 APPENDIX - A page 77)
The expansion tank is located between the two uprights of the
framework and has the job of compensating the increased
volume of primary fluid from heating effect, thanks to the work
done by a rubber membrane loaded with nitrogen beforehand
at 1 bar.
It has been scaled to meet with all engineering solutions
normally used in domestic central heating units. The current
production expansion tank has a capacity of 8 l. and is adequate
for a system containing about 100 l. It may eventually be
integrated with an auxiliary if it should prove to be insufficient.
1.5.20 Fan (C.S.I. only)
(POS. 18 APPENDIX - A page 77)
The fan is located above the combustion chamber (Sect. 1.5.2
page 3) and serves to expel combustion products from the air
box (Sect. 1.5.11 page 5).
Specifically designed for this kind of application, it has the
characteristic of being absolutely silent with top performance.
1.5.21 Venturi and Pitot tube (C.S.I. only)
(POS. 19 APPENDIX - A page 77)
TheVenturi andPitottube areinstalledon the fanscrewconveyor
(Sect. 1.5.20 page 7) and continuouslycorrect scavenging of
products of combustion.
The first device has the job of signalling static pressure value
as combusted gas flows through, while the second measures
thetotal pressure.The differenceinpressure workson thesafety
pressure switch membrane (Sect. 1.5.8 page 4), through two
small tubes, switching on the microswitch.
Fig. 1.19
Fig. 1.20
Fig. 1.21
Fig. 1.22
Fig. 1.18

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DHW
OUT IN
1.6 DESCRIPTION OF OPERATING
PRINCIPLES
1.6.1 Hydraulic operating principle in DHW
(Fig. 1.23)
When service water taking cock (1) is opened, system water
flows back to DHW input (2), through capacity regulator (3)
and the flow-meter (4). Water getting through the flow-meter,
exceeding a 2,5 l/min capacity, pushes float, located inside it,
upward. This movement allows closing the electric contact,
located in a device out of the flow-meter. By a connection ramp
(5), water flows from flow-meter to flow limiting device (6)
and then into bi-thermal exchanger (7).
1.6.2 Electric operating principle in DHW
(see APPENDIX - E pages 81, 82)
In order to get hot water ready only, in summer, set function
selector on « » DHW symbol. When hot water cock is
opened and capacity exceeds 2,5 l/min, the flow-meter,
measuring water flowing through the circuit, check pressure
switch closing by electric enabling; the pressure switch starts
ignition sequence:
- C.A.I. version:
When activated, water pressure switch enables ignition; gas
valve operating devices are fed.
- C.S.I. version:
When activated, water pressure switch feeds the fan, while
gas valve operating devices are fed.
Under temperature request condition, the burner switches on
and gas solenoid valve proportionally opens shutter to allow
slow burner ignition- automaticallyadjusted bymicroprocessor
- then maximum power is reached until temperature set on
selector is obtained.
According to taking capacity, burner flame automatically fits
hot water requests.
Both temperature selector and sensor provide for a resistance
value to board integrated component, which, at the beginning
(cold) controls burner maximum operation, until temperature
read on secondary by NTC sensor, compared by main board
integrated component, with resistance set on DHW temperature
selector, approaches temperature set: then minimum level is
reached in modulation phase.
The burner switches off 5°C after temperature set and switches
on 1°C below.
Finally, when DHW cock is opened, the operating sequence is
the following:
C.A.I. version
Flow-meter
Water pressure switch check
Burner
C.S.I. version
Flow-meter
Water pressure switch check
Quiescent safety pressure switch
Fan
Safety pressure switch enabled
Burner
1.6.3 DHW temperature adjustment
To adjust DHW temperature (bathrooms, shower, kitchen, etc.)
to adjust CH temperature, remove function selector and act on
right potentiometer (Fig. 1.24).
Fig. 1.23
Fig. 1.24

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CH
OUT IN
Gas solenoid valve opens the shutter proportionately to allow
slow burner ignition, automatically adjusted by
microprocessor. The boiler will then work at 75%capacity of
its maximum power for 15 min.; then it starts delivering
maximum power, if necessary, and modulating when tempe-
rature set on heating selector is reached. If, during the first
15 min., power necessary is lower than 75%,boiler modulates
below this value, without waiting 15 min. expiry.
When the temperature set is reached by heating selector, the
main board automatically updates power to system request.
If, also when idling, power supplied exceeds temperature
request, the main board switches off the burner, allowing it
to switch on again after 3 min. ±10 s only, then it operates
idling for 2 more min.
To summarise, once the hot water tap is closed, in
« »WINTER position and when the room thermostat
signals for it, the working sequence is the following:
C.A.I. version
Room thermostat enabling
Circulator
Water pressure switch check
Burner
C.S.I. version
Room thermostat enabling
Circulator
Water pressure switch check
Quiescent safety pressure switch
Fan
Safety pressure switch enabled
Burner
1.6.4 Hydraulic operating principle in CH
(Fig. 1.25)
When request is set on CH side, circulator (1) is fed, generating
a depression on return (2).
The water, pushed into primary exchanger (3) by circulator,
flows along the connection ramp to system delivery.
System pressure greater than 0.45 bar closes the contact of the
water pressure switch and burner ignition is started.
During normal operating conditions, i.e. low-load-loss system
or water circulation exceeding 450 l/h, the automatic by-pass
(4) is closed and then making the water flow only towards the
system delivery.
On the contrary, if relevant load losses exist on the
system, the circulator unloads its head onto the by-pass
shutter surface (4); the by-pass connecting return and
delivery by duct and internal recirculation is obtained, to
be added to water coming from system return.
Fig. 1.25
1.6.5 Electric operating principle in CH
(APPENDIX - E pages 81, 82)
When selector is in CH « », with room thermostat
request, circulator is activated. By water pressure switch, proper
water pressure is checked and burner ignition is not enabled in
case of system pressure less than 0.45 bar.
- C.A.I. version
Now, if primary water temperature read by NTC sensor is
lower than temperature set on the control panel, ignition
starts up.
- C.S.I. version
Fan is activated and its movement generates vacuum and
pressure - repeatedly read byVenturi and pitot pipe - which
act on pressure switch. This pressure switch closes its
internal electric contact and enables opening of gas valve
operating devices; at the same time, it starts ignition by
appliance flame control.

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1.6.6 CH water temperature adjustment
The selection scale is divided into 3 sectors, to be set by
potentiometer located on the left side, under the main knob
(Fig. 1.26).
EXAMPLES OFADJUSTMENTS
- FIRST SECTOR (Fig. 1.27)
When temperature is set at 44°C, boiler switches off at 44°C +
6°C and switches on again at 44°C - 6°C.
- SECOND SECTOR (Fig. 1.27)
When temperature is set at 56°C, boiler increases automatically
set by 5°C (61°C), after 20 min., by 5°C (66°C) after 20 min.
and sets back to initial value (56°C), after 20 min.
During potentiometer adjustment, when adjustment
level enters this sector, two leds located under the
central knob start flashing at very high frequency for
about 4 sec. (Fig. 1.26).
- THIRD SECTOR (Fig. 1.27)
When temperature is set at 66°C, boiler switches off at 66°C +
6°C and switches on again at 66°C - 6°C.
When required by the room thermostat, each time
the boiler switches of to reach pre-setting levels, re-
ignition will happen only after 3 mins. Then the
boiler will switch on at minimum for 2 mins. only if
the above conditions are respected for each working
sector; after this self-timing phase, the boiler will
work as described in paragraph 1.6.5 p.9.
Timing can be cut off by moving jumper CM1 to Ti-
mer OFF position as shown in figure Fig. 1.28.
1.6.7 Main functions
Pump self-blocking cycle
This function is active when boiler is in « » DHW, «
»CH and OFF modes.
After 24-hour continuous non-operation and 3 hours after last
DHW ignition, the pump is operated for 20 secs.
All request in CH or in DHW mode stoped the actual
function to call the calor request.
Anti-frost cycle
The pump is operated for 15 minutes if DHW temperature is ≤
7°C. If, during these 15 minutes, DHW temperature increases
to exceed 10°C, the pump is stopped, otherwise, after 15
minutes, the pump stops for 2 hours, then the cycle is repeated.
If DHW temperature decreases below 5°C, pump and burner
are switched on to mechanical idling. The cycle is switched off
when DHW temperature is ≥30°C. When burner is switched
off, a 30-second post-circulation is activated.
All request in CH or in DHW mode stoped the actual
function to call the calor request.
Fig. 1.26
Fig. 1.27
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Fig. 1.28
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Second
sector
First
sector
Third
sector

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2 FIRST IGNITION
2.1 PRELIMINARY OPERATIONS
Before carrying out ignition and working inspection on the
boiler it is essential to check that:
- fuel and water taps supplying the system are open.
- The type of gas and supply pressure correspond to those
designed to be used by the boiler, as shown on serial number
plate(Sect. 1.4 page 2).
- The vent of the air vent bottle is open (Sect. 1.5.3 page 3).
- Wiring has been done properly (Sect. 7.3 page 71).
- The flues for fuel exhaust and combustion air are adequate
(Sect. 7.5 page 73, Sect. 7.6 page 73 and Sect. 7.7 page 75).
- Pre-charge of the expansion tank must be at 1 bar. Remove
the protection cover from the control and pressure valve on
the upper part of the tank (Fig. 2.2); with a manometer check
the pre-charge pressure and if necessary top up with a
compressor.
The check must be carried out with the system empty.
- The circulator turns freely; unscrew the inspection screw and
check that the motor shaft moves freely using a broad-tipped
screwdriver (Fig. 2.3).
2.2.1 Operations for boiler ignition and use
Openthe gascock byrotatingtheknob underthe boilercounter-
clockwise, to allow fuel flow.
Fig. 2.1
Fig. 2.3
!!
Fig. 2.5
Fig. 2.6
Fig. 2.2
!!
Fig. 2.4
Protecttheelectricaldevicesunderneaththe circulator
from eventual water leaking out before loosening and
removing the circulator plug.
- the pressure of the water circuit is between 1 bar and 1.5
bar (Sect. 7.4 page 72).
2.2 START UP
Place function selector on symbol «» WINTER or
« » SUMMER following the operation selected.

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2.2.5 CH temperature adjustment
To adjust CH temperature, remove function selector and act on
left potentiometer as shown in figure Fig. 2.10
2.2.6 Controls during and after first start up
After ignition check that the boiler effectively proceeds with
ignition and switching off correctly by:
- function selector;
- heating and hot water potentiometer;
- required room temperature (adjusting the room thermostat
or timer).
Make functional textes pages 65, 66 e 67.
After several minutes of working continuously by turning the
main system switch to “on”, the function selector on « »
SUMMER, keeping the sanitary system on, alloying elements
andproduction debriswillhaveevaporated andit will bepossible
to:
- control pressure of gas supply and burner (Sect. 2.4 page
13);
- control combustion parameter (see section 2.5).
Also check that the heating hydraulic circuit pressure
when cold is between 1 and 1.5 bars after air has been
removed from the circuit (Sec. 7.4 p. 72).
Fig.2.10
2.2.3 DHW temperature adjustment
To adjust DHW temperature (bathrooms, shower, kitchen, etc.)
To adjust CH temperature, remove function selector and act on
right potentiometer.
Fig. 2.8
2.2.4 CH operation
For CH use, place function selector on symbol « »
WINTER. Boiler is activated to produce heating and domestic
hot water.
Fig. 2.9
!!
!!
2.2.2 DHW operation
For DHW use, place function selector on « » SUMMER
i.e. the boiler only produces domestic hot water (bathrooms,
kitchen, etc.).
Fig. 2.7

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2.4 PRESSURE CALIBRATION ON THE
BURNER
2.4.1 Preliminary operations
The following are necessary for calibration and checks: a
pressure gauge (differential manometre), a medium flat
screwdriver, as well as 10-mm socket wrenches.
Act as follows:
- connect pressure gauge to pressure outlet (1 - Fig. 2.13)
upstream of gas valve;
- check static pressure, with boiler off, does not exceed the
limit value of 50 mbar;
- enable « » DHW operation by dashboard controls;
- select maximum DHW temperature value;
- fully open DHW cock and check, by pressure gauge
connected, that gas dynamic pressure is not below the
following values:
- 15 mbar for methane
- 37 mbar for LPG
- disconnect pressure gauge and close outlet (1 - Fig. 2.13).
2.4.2 Pressure calibration on the burner
See the following operations:
- disconnect compensating outlet (4-Fig.2.13) of gas val-
ve (C.S.I. only);
- connect a pressure gauge end to pressure outlet (2 -Fig.
2.13) downstream of gas valve and the other end to
compensating outlet on air chamber (C.S.I. only);
- select maximum DHW and CH temperature values by
controls;
- remove protection cap from idling adjusting screw (3 -
Fig. 2.13).
2.3 GAS TRANSFORMATION
PROCEDURES
Shifting from a gas to another, belonging to another group,is
easy also when the boiler is already installed. For the relevant
pressure values, refer to “GAS PRESSURE TABLE”
APPENDIX - D page 80.
Replace burner nozzles as follows (see table 4.4.14 pages 37
and 38):
- stop boiler voltage and close gas central cock;
- remove the cover;
- remove combustion chamber front cover;
- remove burner unit by untightening screws (A) fixing it to
gas manifold (Fig. 2.11).
Now, replace nozzle with manifold installed on the boiler;
install nozzles using new gaskets available in the
transformation kit.
Carefully check nozzle cleaning: also a partial
obstruction would seriously affect combustion.
Fig.2.11
Fig.2.13
Fig.2.12
!!
TRASFORMATION FROM LPG TO MTN
- Remove jumper installed in control board, in position CM2
(Fig. 2.12).
TRASFORMATION FROM MTN TO LPG
- Place jumper available in the kit in position CM2 in control
board, as shown in figure 2.12.
4
2
1
3

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2.4.2.1 Maximun calibrations
- Open a DHW cock at maximum capacity (let it open for at
least two minutes before calibrating).
If possible, check maximum current available is delivered
to modulator by a millamperometre connected in series to a
modulator cable (MTN 120 mA and GPL 165 mA);
- use a fork wrench CH10 - or proper instrument - to act on
the valve and adjust maximum speed (see GAS PRESSURE
TABLE - APPENDIX D page 80);
- close the cock.
Fig.2.17
Fig.2.14
boiler.
- Make sure the burner goes off by lowering the temperature
of the heating potentiometer.
- Turn the heating potentiometer to maximum.
- Gas pressure will be reduced to minimum after the phase of
slow ignition so that it will be possible to use the P4
potentiometer (Fig. 2.16) and set the minimum heating until
reading the degrees on the gauge (GAS PRESSURE TABLE
- APPENDIX D page 80).
- Turn the function selector and the main system switch to
OFF before removing the SM1 jumper.
2.4.2.3 Minimum heating gauging (C.S.I. only)
- Turn the main system switch to OFF.
- Open the boiler instrument panel and remove the plastic
covers that give access to the jumpers and trimmers (Fig.
2.16).
- Insert a jumper in position CM1 to set the timer to zero as
indicated in the figure Fig. 2.16.
- On the control panel:
• select « » WINTER;
• turn the heating potentiometer to maximum
- Use the eventual room thermostat or timer to start up the
2.4.2.2 Idling calibration
- Open a DHW cock at maximum capacity (let it open for at
least two minutes before calibrating);
- disconnect a modulator faston;
- use a cross screwdriver - or proper instrument - to act on the
idlingredscrewandadjustminimumspeedcarefully checking
data comply with GAS PRESSURE TABLE -APPENDIX
D page 80);
- connect faston to modulator again and close DHW cock.
Fig.2.15
2.4.3 Slow ignition
Slow ignition cannot be adjusted by a technician, as its value is
preset by microprocessor.
Incaseof transformationfrommethane toLPG,insert
jumper CM2 (Fig. 2.12 page 13) to increase modulator
pressure, then increasing gas inflow to the burner. In
case of transformation from LPG to methane act in
reverse order.
2.4.4 Ionization current measuring
Measure ionization current by connecting a serial d.c. micro-
amperometer to ignition/detection electrode with a parallel 0.22
µF 400 V condenser between prods, as in figure Fig. 2.17.
!!
Fig. 2.16
Flame
control board
Micro-
amperometer

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- remove the probe from the analyser and and switch off
analysis device (Fig. 2.20).
C.S.I. version:
- unscrew the screw (1 - Fig. 2.22) fixing the combustion
analysis plug;
- insert the analyser probes into the housing on the air
box;
- switch on the combustion analysis control or else turn on a
hot water tap completely;
- it will be possible to control combustion with the boiler at
maximum on « » SUMMER position and sanitary
thermostat at maximum degree, by inserting the probe of
the analyser into the hole made beforehand (Fig. 2.21);
- turn off the combustion analysis control or else turn off the
hot water tap when controlling has finished;
- remove the analyser probes, put the plug back in and screw
it up (Fig. 2.22).
2.5 COMBUSTION PARAMETER
CONTROL
The following operations must be done to check
combustion:
- remove function selector;
- turnthe dial underneath upward tothe spannerposition (Fig.
2.18);
- wait until the yellow led on the control panel lights up (Fig.
2.19);
Fig.2.18
Fig. 2.21
Fig. 2.22
Fig. 2.20
!!
Fig. 2.19
- then turn the dial downward until it is in « »
WINTER position;
- the boiler is now working at maximum without any
modulation for 15 minutes maximum..
The function will stay on until the dial is turned back to OFF-
RESET.
The function switching off the boiler when the
maximumlimit of the110°C isreachedstaysonduring
the combustion analysis phase.
C.A.I. version:
- Drill a hole into the straight part of the tube after it comes
out from the hood at least 400÷500 mm (complying with
Regulations in force - Fig. 2.20);
- activate the COMBUSTION ANALYSIS function, or fully
turn on a hot water tap selecting the « » SUMMER
mode and maximum value of the hot water potentiometer
(Fig. 2.21);;
- check combustion by inserting the analysis probe into the
previously made hole;
- turn off the combustion analysis control or else turn off the
hot water tap when controlling has finished;

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3 SWITCHING OFF BOILER
3.1 TEMPORARY SWITCHING OFF
Turn the function selector (Fig. 3.1) to OFF for temporary
absence (weekend, short journeys, etc.).
While the electricity and fuel supply is still working, the boiler
is protected by systems:
-Circulator anti-blockage: the circulator starts every 24
hours of stand-by and after 3 hours from the last time the
sanitary system was used.
-Antifreeze: this will be started if the temperature of the
water in CH circuitfalls to below 7°C, the circulator is timed
for a cycle of 15 min. every 2 hours and the circulator will
switch itself off when the temperature of the water in the
boiler exceeds 10°C. The burner will ignite at the lowest
heating when the temperature of the water primary drops to
below 5°C until the temperature of the water reaches 30°C.
3.2 SWITCHING OFF FOR LONG PERIODS
IThe following operations should be done for CIAO boilers that
are not going to be used for long periods:
- Turn the function selector (Fig. 3.1) to OFF;
- turn the system’s main switch to “OFF” and check that the
green LED has gone off;
- turn off the fuel and water taps of the heating and sanitary
system.
!!
Fig. 3.1
Fig. 3.2
Inthis case theantifreezeand antiblockagesystems are
disconnected.
Empty the heating and sanitary systems if there is any
danger of freezing.
!!

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BURNER CLEANING AND NOZZLE CHECK
Table 4.4.14 page 37- 38
BI-THERMAL EXCHANGER CLEANING (CALCIUM REMOVING
WASHING, IF NECESSARY) - Table 4.4.8 pages 28-30
FAN, VENTURI AND PITOT CLEANING - Table 4.4.19 page 44
DHW START-UP CHECK WITH MINIMUM CAPACITY
- WORKING TESTS FOR BOILER ON SANITARY page 67
CALIBRATIONSANDADJUSTMENTS CHECK - Sect. 2.4 page 13
CHECKS ON BLOCK SAFETY DEVICES, MODULATION, OPERATORS
CLOSINGAFTER FLAME EXTINGUISHING
- WORKING TESTS FOR BOILER ON HEATING pages 65-66
AND ON SANITARY page 67
XXX
EXPANSION TANK LOAD CHECK - Sect. 2.1 page 11
X
4 MAINTENANCE
4.1 REGULAR PROGRAMMED MAINTENANCE TABLE
XXX
X
XXX
X
XXX
X
XXX
X
XX
XX
4.2 TOOLING NEEDED FOR THE BOILER MAINTENANCE WORKS
- Magnetic PH1 screwdriver
- Magnetic PH2 screwdriver
- Broad tipped screwdriver
- 7mm socket wrench
- 5mm – 13mm – 23mm – 24mm – 30mm wrenches
- Scissors
- Molokite 111 type lubricant
- Cleaning rags
- Thermoconductive paste
- Thermoconductive paste
- Pliers
EXHAUST AND SUCTION DUCTS CHECK - TERMINALS
CHECK - Sect. 7.5 e 7.6 page 73
ELECTRODE CHECK AND CLEANING - Table 4.4.3 pages 22-23
CHECK ON FILTER - Table 4.4.4 page 24, CAPACITY LIMITING DEVICE -
Sect. 1.5.6 page 4, BY-PASS - Table 4.4.15 page 39, SEALSANDLOADINGCOCK
- Sect. 7.4 page 72
COMBUSTION ANALYSIS - Sect. 2.5 page 15
XXX
X
XXX
X
XX
XX
OPERATIONS TO BEPERFORMED AFTER THE: 1°
year 2° year 3° year 4° year

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4.3 SAFETY NORMS
Boiler installation and any other assistance and maintenance
must be done by Qualified Personnel according to current codes
of practice and legislation in Countries where the product is
sold.
Make sure the following operations have been carried
out before any jobs to be done:
- disconnect the boiler from the electricity supply;
- turn off the gas tap;
- ifnecessaryturnoffthe sanitary waterinlet and taps
for heating. See paragraph FILLING AND
EMPTYING SYSTEMS in the section 7.4 page 72.
4.4 ACCESSIBILITYTOTHECOMPONENTS
This chapter gives detailed explanations of how to gain access
and dismantle the main components of the boiler.
The data sheet on the component of interest can be consulted
quickly with the help of the index given here below.
INDEX:
• Burner page 19
• Circulator page 20
• Ignition and control electrode pages 22-23
• Flowmeter page 24
• Case page 25
• Water pressure switch page 26
• Safety pressure switch (C.S.I. only) page 27
• Bithermal exchanger pages 28-30
• Electronic control panel page 32
• NTC heating temperature control probe page 33
• NTC sanitary temperature control probe page 34
• Fumes thermostat (C.A.I. only) page 35
• Limit thermostat page 36
• Nozzles pages 37-38
• By-pass valve page 39
• Gas valve pages 40-41
• Safety valve page 42
• Expansion tank page 43
• Fan (C.S.I. only) page 44
• Venturi and Pitot tube (C.S.I. only) pag. 44
!!