Fondital TENERIFE KC 24 Quick start guide

IST 03 C 1408 - 01
TENERIFE
KC 24
INSTALLATION, USE AND MAINTENANCE
EN
Translation of the
original instructions
(in Italian)
It is compulsory to read this manual before proceeding with the boiler installation, use and
maintenance operations.
This boiler is intended for production of hot technical water only:
• For heating of residential, commercial and industrial rooms.
• For heating of industrial process water.
• For indirect production of domestic hot water.
Any other use is forbidden.

2
Dear Sirs,
thank You for choosing and buying one of our products. Please read these instructions carefully in order to properly install, operate,
and maintain the product.
WARNING
We inform users that:
• Boilers shall be installed by an authorised company under the requirements set forth by the prevailing rules, in full
compliance with the prevailing regulations and standards.
• Anyone entrusting installation to an unqualied installer will be subject to administrative sanctions.
• Boilers must be maintained by qualied personnel only, under the requirements set forth by the prevailing rules.
WARNING
According to European Directive 2012/19/EU on waste electrical and electronic equipment (WEEE) the
crossed-out wheelie bin symbol indicated on the boiler and on the package means that the boiler, at the
time of its decommissionig, must be collected and disposed of separately from other waste (see Decom-
missioning, disassembly and disposal).
We hereby inform you that certain models, versions and/or accessories relevant to the products this manual refers to,
might not be available in some countries.
Therefore, it is recommended to contact the manufacturer or the importer in order to get the necessary information about
the actual availability of such models, versions and/or accessories.
The manufacturer reserves the right to modify the products and/or its components as deemed necessary, in any moment
and without prior notice.
This instruction manual is available in two languages, Italian and English, without prejudice to the prevalence of Italian
language in case of di󰀨erences in translation and/or dispute on construction of the text.

3
General notes for installing and maintenance technicians, and users
This instruction manual is an integral and essential part of the product. It shall be supplied by the installer to the user who shall keep
it carefully to consult it whenever necessary.
This document shall be supplied together with the equipment in case the latter is sold or transferred to others.
WARNING
This boiler is intended for production of hot technical water only:
• For heating of residential, commercial and industrial rooms.
• For heating of industrial process water.
• For indirect production of domestic hot water.
Any other use is forbidden.
DANGER
This boiler must be installed by qualied personnel.
The installation by unqualied personnel is forbidden.
DANGER
This boiler must be installed in compliance with the requirements of the technical standards and legislation in force re-
lating to gas appliances, particularly with reference to ventilation of the premises.
Any installation that does not comply with the requirements of the technical standards and legislation in force is forbid-
den.
DANGER
This boiler must be installed according to the manufacturer’s instructions given in this manual. Incorrect installation may
cause injury to persons and/or animals and damage to property. The manufacturer shall not be held liable for any such
injury and/or damage.
WARNING
This boiler must be installed inside the building or in a partially sheltered place.
A partially sheltered place is a place which is not directly exposed to atmospheric agents.
Any installation in a place that is not partially sheltered is forbidden.
DANGER
This boiler must be correctly and safely connected to an electrical system compliant with the existing technical stand-
ards.
Any incorrect and unsafe connection to the electrical system is forbidden.
It is forbidden to connect the boiler to an electrical system lacking a di󰀨erential switch to protect the boiler power line.
Any connection to an electrical system lacking a proper grounding system is forbidden.
WARNING
The boiler is supplied with a three-pole power cable, already connected to the electronic board and it is provided with a
safety clamp.
This boiler must be connected to a 230V power supply network, as indicated on the label a󰀩xed to the power cable.

4
DANGER
Carefully read the instructions relating to air intake and ue gas venting systems in the specic section of this manual.
DANGER
This boiler must be connected to a gas distribution system which complies with the existing technical standards.
Check the gas system state of conservation before installing the boiler.
Any connection to a gas system which does not comply with the existing technical standards is forbidden.
When connecting the boiler to gas supply network, it is compulsory to install an appropriately sized gasket made from
suitable material.
The boiler gas inlet coupling is not suitable for hemp, teon tape or similarly made gaskets.
After connecting the boiler, check the connection for tightness.
Once gas is in the pipes, leak test by a naked ame is forbidden; use specic products available on the market.
DANGER
With gas red boilers, take the following measures if you smell gas:
• Do not turn on or o󰀨 electric switches and do not turn on electric appliances.
• Do not ignite ames and do not smoke.
• Close the main gas cock.
• Open doors and windows.
• Contact a Service Centre, a qualied installer or the gas supply company.
Never use a ame to locate a gas leak.
The boiler is designed for installation in the countries indicated on the technical data plate applied both to the package
and to the boiler itself: installation in any other country may be a source of danger for people, animals and/or property.
The manufacturer will bear no contractual and tortious liability for failure to comply with all the instructions above.
Before installing the boiler, check that the technical data correspond to the requirements for its correct use in the system.
Check that the boiler is intact and it has not been damaged during transport and handling. Do not install equipment which is clearly
damaged and/or faulty.
Damage and/or injury caused by incorrect installation or use and/or damage and/or injury due to non-observance of the manufactur-
er’s instructions shall release the manufacturer from any and all contractual and extra-contractual liability.
Do not obstruct the air intake openings.
Only original accessories or optional kits (including the electric ones) are to be installed.
Properly dispose of the packaging as all the materials can be recycled. The packaging must therefore be sent to specic waste man-
agement sites.
After removing the packaging, make sure that its elements (clips, plastic bags, foam polystyrene etc.) are not left within the reach of
children as they are potential hazard sources.
In the event of failure and/or faulty functioning, switch o󰀨 the boiler. Do not attempt to make repairs: contact qualied technicians.
Original parts must be used for all repairs to the boiler.
Non-observance of the above requirements may a󰀨ect the safety of the boilers and endanger people, animals and/or property.
This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack
of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person
responsible for their safety.
Children should be supervised to ensure that they do not play with the appliance.

5
DANGER
Before starting the boiler, and each time it is at a standstill for several days, make sure the trap is full of water.
If the trap is empty, ll it by pouring water into the boiler through the ue gas venting duct.
WARNING
The boiler must be serviced periodically as indicated in the relevant section of this manual.
Appropriate boiler maintenance ensures e󰀩cient operation, environment preservation, and safety for people, animals
and objects.
Incorrect and irregular maintenance can be a source of danger for people, animals and property.
The user is strongly advised to have the system serviced and repaired by qualied personnel, satisfying all prevailing law require-
ments, and trained to properly carry out these operations.
In the event of long periods of inactivity of the boiler, disconnect it from the electrical power mains and close the gas cock.
WARNING
With the electrical power disconnected and the gas cock closed, the device's electrical anti-freeze function does not work.
Should there be a risk of freezing, add antifreeze: it is not advisable to drain the system as this may result in damage; use specic
anti-freeze products suitable for multi-metal heating systems.
DANGER
Damage and/or injury caused by incorrect installation and/or incorrect use and/or unauthorized changes to the boiler
and/or non-observance of the manufacturer’s instructions and/or of the relative standards/laws in force in the country of
installation, shall release the manufacturer from any and all liability.

6
1. Instructions for the user .....................................................9
1.1 Control panel.......................................................................................................................................................... 9
1.2 Interpreting boiler status from display indications .................................................................................................11
1.3 Boiler operation .................................................................................................................................................... 12
1.4 Boiler shut-down................................................................................................................................................... 15
1.5 Maintenance......................................................................................................................................................... 17
1.6 Notes for the user................................................................................................................................................. 17
2. Technical features and dimensions............................................ 18
2.1 Technical features ................................................................................................................................................ 18
2.2 Dimensions........................................................................................................................................................... 20
2.3 Hydraulic diagram ................................................................................................................................................ 21
2.4 Operating data...................................................................................................................................................... 22
2.5 General characteristics......................................................................................................................................... 22
2.6 ERP and Labelling data........................................................................................................................................ 24
3. Instructions for the installer ..................................................25
3.1 Installation standards ........................................................................................................................................... 25
3.2 Choosing where to install the boiler ..................................................................................................................... 25
3.3 Positioning the boiler............................................................................................................................................ 25
3.4 Installing the boiler ............................................................................................................................................... 27
3.5 Boiler room ventilation.......................................................................................................................................... 27
3.6 Air intake and ue gas venting system................................................................................................................. 28
3.7 Measuring combustion eciency during operation .............................................................................................. 36
3.8 Connection to gas mains...................................................................................................................................... 37
3.9 Hydraulic connections .......................................................................................................................................... 37
3.10 Connection to electrical mains ............................................................................................................................. 39
3.11 Connection to ambient thermostat (optional) ....................................................................................................... 39
3.12 Ambient probe installation (optional).................................................................................................................... 39
3.13 Installation and operation with Open Therm Remote Control (optional) .............................................................. 40
3.14 Selecting the operating range in heating mode.................................................................................................... 40
3.15 Installation of the (optional) external probe and sliding temperature operation ................................................... 41
3.16 TSP parameters ................................................................................................................................................... 43
3.17 Filling the system.................................................................................................................................................. 47
3.18 Filling the trap....................................................................................................................................................... 47
3.19 Starting up the boiler ............................................................................................................................................ 47
3.20 Available head...................................................................................................................................................... 48
3.21 Wiring diagram ..................................................................................................................................................... 49
3.22 Adaptation to other gas types............................................................................................................................... 51
3.23 Gas valve setting.................................................................................................................................................. 52
4. Testing the boiler.......................................................... 53
4.1 Preliminary checks ............................................................................................................................................... 53
4.2 Switching on and switching o ............................................................................................................................. 53
5. Maintenance .............................................................54
5.1 Maintenance schedule ......................................................................................................................................... 54
5.2 Combustion analysis ............................................................................................................................................ 55
5.3 Extraordinary maintenance .................................................................................................................................. 55
6. Decommissioning, disassembly and disposal....................................56
7. Malfunctions, possible causes and solutions ....................................57
7.1 Troubleshooting.................................................................................................................................................... 57

7
Fig. 1 Control panel .......................................................................................9
Fig. 2 Filler cock .........................................................................................16
Fig. 3 Dimensions........................................................................................20
Fig. 4 Hydraulic diagram...................................................................................21
Fig. 5 Paper template .....................................................................................26
Fig. 6 Split kit installation ..................................................................................29
Fig. 7 Coaxial kit installation................................................................................29
Fig. 8 Installation examples ................................................................................30
Fig. 9 Pipe installation ....................................................................................30
Fig. 10 Wall-mounted terminal installation .....................................................................31
Fig. 11 Tile for pitched roofs ................................................................................31
Fig. 12 Roof ue installation ................................................................................32
Fig. 13 Type C13 - C33 coaxial ducts.........................................................................34
Fig. 14 Type C12 - C33 coaxial pipes dimensions ...............................................................34
Fig. 15 Splitter kit ........................................................................................35
Fig. 16 Dimensions for split pipes............................................................................35
Fig. 17 Caps position .....................................................................................36
Fig. 18 Hole position......................................................................................36
Fig. 19 Connection to gas mains ............................................................................37
Fig. 20 Condensate drain ..................................................................................38
Fig. 21 Thermoregulation curves ............................................................................42
Fig. 22 Available head ....................................................................................48
Fig. 23 Wiring diagram KC .................................................................................49
Fig. 24 Gas diaphragm replacement .........................................................................51
Fig. 25 Adjusting CO2 value................................................................................52

8
Tab. 1 Adjustment specications ............................................................................22
Tab. 2 General specications ...............................................................................22
Tab. 3 Combustion specications KC 24 ......................................................................23
Tab. 4 Additional specications..............................................................................23
Tab. 5 ERP and Labelling data..............................................................................24
Tab. 6 Burner re-ignition temperature.........................................................................40
Tab. 7 Limits to be set for TSP parameters and default values in relation to boiler type (TSP0) - I ..........................43
Tab. 8 Limits to be set for TSP parameters and default values in relation to boiler type (TSP0) - II .........................44
Tab. 9 Limits to be set for TSP parameters and default values in relation to boiler type (TSP0) - III .........................45
Tab. 10 Limits to be set for TSP parameters and default values in relation to boiler type (TSP0) - IV........................46
Tab. 11 Gas diaphragm diameter (mm) .......................................................................51
Tab. 12 Flue CO2 content..................................................................................52

9
Instructions for the user
1. Instructions for the user
1.1 Control panel
F
67 4
RESET
8 5
3
12
AD
RESET
BC
E
Fig. 1 Control panel
A. Domestic hot water settings (+/- DHW).
B. Select operating status and conrm parameters.
C. Alarm reset and back to the starting page during parameter selection (RESET).
D. Central heating water temperature settings and parameter settings (+/- CH).
E. LCD display.
F. Heating system water pressure gauge.

10 Instructions for the user
Ref. Description Steady on Flashing
1 Alphanumeric indicator Temperature, parameter values
and fault indication. Not used.
2 Parameter indicator Indication of "parameter" inside the
parameter menu. Not used.
3 Flame lighting indicator Lit ame indication. Not used.
4 Central heating indicator CH function activated.
Displaying of the heating tempera-
ture set-point or heating function in
progress.
5RESET indicator The boiler can be reset. Not used.
6 Parameter editing indicator
During parameter editing, the
wrench symbol stays on until the
set datum is conrmed.
When edited parameter value is
conrmed.
7Flue cleaning function indicator
(for the installer) Flue cleaning function in progress. Indicates that you are accessing
the ue cleaning function.
8 DHW indicator DHW function activated.
Displaying of the DHW tempera-
ture set-point or DHW function in
progress.

11
Instructions for the user
1.2 Interpreting boiler status from display indications
1.2.1 Normal operation
Boiler in STANDBY mode
Boiler in SUMMER mode
No active function
Flow temperature displayed
Boiler in WINTER mode
No active function
Flow temperature displayed
Boiler in CENTRAL HEATING ONLY mode
No active function
Flow temperature displayed
Boiler in SUMMER mode
Domestic hot water withdrawal
DHW temperature displayed
Boiler in WINTER mode
Domestic hot water withdrawal
DHW temperature displayed
Boiler in WINTER mode
CH function active
Flow temperature displayed
Boiler in CENTRAL HEATING ONLY mode
CH function active
Flow temperature displayed
1.2.2 Malfunction
To identify any malfunctions, refer to paragraph Troubleshooting on page 57.

12 Instructions for the user
1.3 Boiler operation
1.3.1 Switching on
DANGER
It is presumed that the boiler has been installed by a qualied installer, it has been commissioned and is ready to operate
correctly.
• Open the gas shut-o󰀨 cock.
• Turn the master switch installed ahead of the boiler to ON.
• The display turns on and indicates the function currently active (see Interpreting boiler status from display indications on page 11).
• Select the boiler operating mode: OFF/SUMMER/WINTER/CH ONLY (see Selecting the operating mode on page 12).
• Set desired CH temperature (see CH function on page 12).
• Set desired DHW temperature (see DHW function on page 13).
• Set the desired temperature on the ambient thermostat in the building (if installed).
• If the ambient probe or external probe is present, set the desired ambient temperature value.
WARNING
After a prolonged period with the boiler not in use, and with LPG red boilers in particular, some starting di󰀩culty may
be encountered.
Before starting the boiler switch on another gas powered device (e.g. kitchen range).
Beware that even by following this procedure, the boiler might still experience some starting di󰀩culties and shut down
once or twice. Press the “RESET” button to restore boiler operation.
1.3.2 Selecting the operating mode
To select the boiler operation mode press BOperating mode selection.
Whenever button is pressed, the following modes are enabled in sequence: "SUMMER", "WINTER", "CH ONLY", "OFF".
"SUMMER" operating status
When the "SUMMER" mode is enabled, only the DHW production function is active.
"WINTER" operating status
When the "WINTER" mode is enabled, both DHW and CH functions are active.
"CH ONLY" operating status
When the "CH ONLY" mode is enabled, only the heating water production function is active.
"OFF" operating status
When the "OFF" mode is enabled, no function is active.
1.3.3 CH function
To set the water temperature for central heating, press the +/- CH buttons.
Heating temperature adjustment range depends on the selected operating range.:
• standard range: from 20°C to 78°C (pressing +/- CH);
• reduced range: from 20°C to 45°C (pressing +/- CH).
Operation range selection is to be implemented by an installer or a qualied Service Centre (see par. Selecting the operating range
in heating mode on page 40).
During temperature setting, the symbol ashes on the screen and the CH current temperature setting is displayed.
When the central heating system requests heat, the CH symbol ashes and the current heating ow water temperature is dis-
played.
The waiting time between one boiler ignition and the following one, used to prevent boiler frequent turning on and o󰀨 during heating,
ranges between 0 and 30 minutes (default value: 4 min.), and can be edited with the P11 parameter.
Should water temperature in the system fall below set minimum value, between 20°C and 78°C (default value 40°C for standard
range, 20°C for reduced range) to be edited with the P27 parameter, the waiting time is reset and the boiler re-ignites.
The burner ON symbol shows while the burner is operating.

13
Instructions for the user
1.3.4 DHW function
DHW production function is enabled in one of the following operating modes: SUMMER or WINTER.
Such function has always priority over CH water supply.
To set the domestic hot water temperature, press +/- DHW buttons.
During temperature setting, the symbol ashes on the screen and the DHW current temperature setting is displayed.
The DHW temperature setting range is from +35 °C to +57 °C.
WARNING
A ow limiter is installed within the boiler, which limits DHW output ow rate.
This limit is set to 10 litres per minute.
1.3.5 Freeze protection function
This boiler is tted with a freeze protection system, which works when the following functions are activated: OFF/SUMMER/WINTER/
CH ONLY.
DANGER
The freeze protection function only protects the boiler, not the whole heating system.
The central heating system can be e󰀨ectively protected against icing by using specic anti-freeze products that are suitable for mul-
ti-metal systems.
WARNING
Do not use anti-freeze products for car engines, and check the e󰀨ectiveness of the product used over time.
In case burner cannot be ignited due to the lack of gas, the freeze protection functions are anyway enabled through the circulation
pumps.
1.3.5.1 Flow freeze protection function
When the heating water temperature sensor detects a water temperature of +5 °C, the boiler switches on and stays on at its minimum
heat output until the temperature reaches +30 °C or 15 minutes have elapsed.
The pump continues to operate even if the boiler shuts down.
1.3.5.2 DHW plate exchanger freeze protection function
When the DHW temperature sensor detects a water temperature of +5°C, the boiler switches on and stays on at its minimum heat
output until the DHW temperature reaches +10°C or 15 minutes have elapsed (the deviating valve is in the DHW position).
During the DHW freeze protection operation the temperature detected by the ow probe is constantly checked, and in case it reaches
+60 °C the burner is switched o󰀨.
The burner is switched on again if the operation request in anti-freeze mode is still present and the ow temperature is below +60°C.
The pump continues to operate even if the boiler shuts down.
1.3.5.3 Ambient probe freeze protection function
If the ambient probe detects a temperature below +5°C, a heating request to heat the probe-controlled room is launched.
The heating function ends when the probe ambient temperature reading reaches +6°C.
1.3.6 Anti-seize function
If the boiler remains inactive and connected to the power mains, the circulation pump and the deviating valve will be shortly enabled
every 24 hours so as to avoid any shut-down.
The same applies to the relay which can be freely programmed whenever this latter is used to power a recirculation pump or a devi-
ating valve.

14 Instructions for the user
1.3.7 Timed post-circulation function
After each central heating, DHW or freeze protection request, the pump continues to be powered for 30 seconds.
If a new central heating, DHW or freeze protection request is received during this period, the post-circulation function is cancelled in
order to full the request.
1.3.8 Timed post-ventilation function
After each central heating, DHW or freeze protection request, the fan continues to work for 10 seconds.
If a new operating request is received during this period, the post-ventilation function is cancelled in order to full the request.
1.3.9 Operation with ambient probe
Boiler can be connected to an ambient probe (optional not compulsory, supplied by the manufacturer).
Once the ambient temperature value is known, the boiler automatically regulates the heating water temperature, increasing it as the
ambient temperature decreases and decreasing it when the ambient temperature gets close to the set temperature.
Heating water temperature varies based on a programme written inside boiler electronic microprocessor.
When the ambient probe is connected, the +/- CH buttons are no longer used to set heating water temperature, but to edit ambient
temperature.
During temperature setting, the °C icon ashes on the display and the value being set is shown.
As soon as button is released, icon will continue ashing for approx. 3 seconds, and set value will ash as well.
After this time, value is stored and display standard operation will be restored.
To connect the ambient probe see Ambient probe installation (optional) on page 39.
WARNING
Only original ambient temperature probes supplied by the manufacturer must be used.
The use of non-original ambient probes, not supplied by the manufacturer, may a󰀨ect the operation of the ambient probe
itself and of the boiler.
1.3.10 Operation with external probe (optional)
Boiler can be connected to a probe measuring the external temperature (optional - not compulsory, supplied by the manufacturer)
Once the external temperature value is known, the boiler will automatically adjust the heating water temperature: increasing it as the
external temperature decreases and decreasing it as the external temperature increases. This will both improve room comfort and
reduce fuel consumption. Standard and reduced range max. temperature values will nevertheless be respected.
This boiler operating mode is called "sliding temperature operation".
Heating water temperature varies based on a programme written inside boiler electronic microprocessor.
With an external sensor, the +/- CH buttons no longer set the heating water temperature, and become buttons for changing the cti-
tious ambient temperature, namely the desired theoretical temperature in the rooms to be heated.
During temperature setting, the °C symbol ashes on the display and the value being set is shown.
For optimal curve adjustment, a position close to +20 °C is recommended.
For further details on sliding temperature operation, refer to paragraph Installation of the (optional) external probe and sliding temper-
ature operation on page 41.
WARNING
Only original external temperature probes supplied by the manufacturer must be used.
The use of non-original external probes, not supplied by the manufacturer, may a󰀨ect the operation of the external probe
itself and of the boiler.

15
Instructions for the user
1.3.11 Operation with (optional) remote control
The boiler can also be connected to a Remote Control (optional - not compulsory, supplied by the manufacturer) so as to manage
several boiler parameters, such as:
• boiler status selection.
• ambient temperature selection.
• CH system water temperature selection.
• DHW temperature selection.
• CH system activation time programming.
• boiler diagnostics display.
• boiler reset and other parameters.
To connect the Remote Control, see Installation and operation with Open Therm Remote Control (optional) on page 40.
WARNING
Only use original Remote Controls supplied by the manufacturer.
The use of non-original remote controls, not supplied by the manufacturer, may a󰀨ect Remote Control and boiler opera-
tion.
1.4 Boiler shut-down
The boiler shuts down automatically if a malfunction occurs.
To determine the possible causes of malfunction, see Troubleshooting on page 57.
Below is a list of shut-down types and the procedure to follow in each case.
1.4.1 Burner shut-down
Fault code E01 is displayed ashing on the display in the event of burner shut-down due to missing ame.
If this happens, proceed as follows:
• check that the gas cock is open and light a kitchen gas ring for example to check the gas supply;
• once having checked if the fuel is available, press the Reset button to restore burner operation: if, after two starting attempts, the
boiler still fails to start and enters the shut-down mode again, contact a service centre or qualied personnel for maintenance.
WARNING
If the burner shuts down frequently, there is a recurring malfunction, so contact a service centre or a qualied service
engineer to carry out the maintenance.
1.4.2 Shut-down due to overheating
Fault code E02 is shown on the LCD display in the event of ow water temperature overheating. Contact a service centre or a qualied
service engineer to carry out the maintenance.
1.4.3 Shut-down due to incorrect air/ue gas system draught
The boiler is equipped with a safety device for ue gas exhaustion check.
Should an air intake/ue gas venting system malfunction occur, the control device will shut down the boiler by interrupting the gas
supply to the boiler and the LCD will display the code E03:
In this case, contact a Service Centre or a qualied service engineer to carry out the maintenance.
1.4.4 Shut-down due to low water pressure
Fault code E04 is displayed on the LCD display in the event of shut-down triggered by the water pressure switch.
Fill the system by working on ller cock (A) (see Fig. 2 Filler cock).
Water pressure must be 1÷1.3 bars while the boiler is cold.
In order to restore water pressure, proceed as follows:
• Turn the ller cock anticlockwise to allow water to enter the boiler;
• Keep the ller cock open until the pressure gauge shows a value of 1÷1.3 bar;
• Turn cock clockwise to close it.
Should the boiler shut down frequently, contact qualied personnel or an authorised service centre for maintenance.

16 Instructions for the user
DANGER
Make sure you close ller cock (A) carefully after lling procedure is completed.
If you do not, when the pressure increases, the safety valve may activate and discharge water.
A
Fig. 2 Filler cock
1.4.5 Alarm due to temperature probe malfunction
The following fault codes are shown on the display in the event of burner shut-down due to a temperature probe fault:
• E05 in this case, the boiler does not work.
• E06 in this case, the boiler functions in central heating mode only, and the DHW function is disabled.
• E15 for the return probe; in this case the boiler functions normally.
• E23 for the external probe; in this case the boiler works normally. Operation with external probe is disabled.
• E44 for the ambient probe; in this case the boiler works normally. Operation with ambient probe is disabled.
WARNING
In any case, contact a service centre or qualied personnel for maintenance.
1.4.6 Alarm due to (optional) Remote Control connection malfunction
The boiler recognises whether or not there is a Remote Control (optional, not compulsory).
If the boiler does not receive information from the Remote Control after the Remote Control itself is connected, the boiler attempts to
re-establish communication for 60 seconds, after which the fault code E31 is shown on the remote control display.
The boiler will continue to operate according to the settings on the touch screen and ignore the Remote Control settings.
WARNING
Contact a service centre or a qualied service engineer to carry out the maintenance.
The remote control can indicate faults or shut-down conditions and can also restore boiler operation after shut-down up to a maximum
of 3 times in a 24 hour period.
If the maximum number of attempts is reached, fault code E99 is shown on the boiler display.
To reset error E99, disconnect and reconnect the boiler from the mains power.

17
Instructions for the user
1.4.7 Shut-down for fan malfunction
The fan operation is constantly monitored and in case of malfunction the burner goes o󰀨; the code E40 ashes on the display.
This mode is maintained until the fan recovers normal working parameters.
If the boiler does not start and remains in this mode, contact a service centre or a qualied service engineer to carry out the mainte-
nance.
1.5 Maintenance
WARNING
The boiler must be serviced periodically as indicated in the relevant section of this manual.
Appropriate boiler maintenance ensures e󰀩cient operation, environment preservation, and safety for people, animals
and objects.
Boilers must be maintained by qualied personnel only, under the requirements set forth by the prevailing rules.
1.6 Notes for the user
WARNING
The user may only clean the external casing of the boiler, employing common household products.
Do not use water!
WARNING
The user may only access parts of the boiler that can be reached without using special equipment or tools. The user is
not authorised to remove the boiler casing or to operate on any internal parts.
No one, including qualied personnel, is authorised to modify the boiler.
The manufacturer shall not be held responsible in case of damage to people, animals, or property due to failure to follow
the above mentioned instructions.

18 Technical features and dimensions
2. Technical features and dimensions
2.1 Technical features
This boiler is equipped with a fully pre-mixed gas burner. The following models are available:
• KC condensing boiler with sealed chamber and forced draught, supplying CH water and instant DHW production;
The following power rates are available:
• KC 24: with heat input of 20.0 kW
All models are equipped with electronic ignition and ionisation ame control device.
The boilers meet local applicable Directives enforced in the country of destination, which are stated on their rating plate.
Installation in any other country may be a source of danger for people, animals and property.
The key technical features of the boilers are listed below.
2.1.1 Manufacturing characteristics
• IPX4D electrically protected control panel.
• Integrated, modulating electronic safety board.
• Electronic start-up with built-in igniter and ionisation ame detection.
• Stainless steel, fully pre-mixed burner.
• Mono-thermal, high e󰀩ciency stainless steel heat exchanger.
• Twin shutter modulating gas valve with constant air/gas ratio.
• Modulating, electronically managed combustion fan.
• High-e󰀩ciency CH circulation pump with built-in air purging device.
• Minimum pressure switch.
• Heating ow water temperature probe.
• Domestic hot water temperature probe.
• Limit thermostat.
• Flue gas thermostat on discharge tower
• Air pressure switch.
• Integrated, automatic by-pass.
• 9-lt- expansion vessel
• System ller cock.
• System water discharge tap.
• Stainless steel plate heat exchanger for DHW production.
• Motorised deviating valve.
• DHW priority ow switch.
• 10 litre/min DHW ow-limiting device.
2.1.2 User interface
• Liquid crystal LCD interface for displaying and setting the boiler operating status: OFF, SUMMER, WINTER and CH ONLY.
• CH water temperature regulator: 20-78°C (standard range) or 20-45°C (reduced range).
• DHW water temperature regulator: 35-57°C.
• System water pressure gauge.

19
Technical features and dimensions
2.1.3 Operating features
• CH electronic ame modulation with timer-controlled rising ramp (60 seconds, adjustable).
• Electronic ame modulation in DHW mode.
• DHW function priority.
• Flow freeze protection function: ON at 5°C; OFF at 30°C or after 15 minutes of operation if CH temperature > 5 °C.
• DHW freeze protection function (CTFS): ON 5°C; OFF 10 °C or after 15 minutes of operation if DHW temperature > 5 °C.
• Timer-controlled ue cleaning function: 15 minutes.
• CH Maximum heat input parameter adjustment.
• Ignition heat input adjustment parameter.
• Pre-selection of the heating range: standard or reduced.
• Ignition ame propagation function.
• CH thermostat timer: 240 seconds (adjustable).
• Heating pump post-circulation function, freeze protection and ue cleaning modes: 30 seconds (adjustable).
• DHW post-circulation function: 30 seconds.
• Post-circulation function for heating temperature > 78 °C: 30 seconds.
• Post-ventilation function after operation: 10 seconds.
• Post-ventilation function for CH temperature >95 °C.
• Circulation pump and deviating valve anti-seize function: 30 seconds of operation after 24 hours of inactivity.
• Anti-water hammer function: adjustable from 0 to 3 seconds via parameter P15.
• Ready for connection to an (optional) ambient thermostat.
• Ready for operation with an external probe (optional, supplied by the manufacturer).
• Ready for operation with an ambient probe (optional, supplied by the manufacturer).
• Ready for operation with an OpenTherm remote control (optional, supplied by the manufacturer).

20 Technical features and dimensions
2.2 Dimensions
11431
66 60 62 67 82 63
81
91
R
M
CGF
S
200
122,5122,5
52,3
122,9
400
700
250
Fig. 3 Dimensions
S Trap inspection cap
M CH system ow (3/4”)
C DHW outlet (1/2")
G Gas inlet (1/2”)
F Cold water inlet (1/2")
R CH system return (3/4”)