Fondital KC 12 Quick start guide

IST 03 C 858 - 01
FORMENTERA
KC 12-24-28-32
KR 12-24-28-32
KRB 12-24-28-32
INSTALLATION, USE AND MAINTENANCE
EN
Translation of the
original instructions (in
Italian)

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 unqualified installer will be subject to administrative sanctions.
• Boilers must be maintained by qualified personnel only, under the requirements set forth by the prevailing rules.
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 differences 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.
DANGER
This equipment has been manufactured to be connected to a room heating system and to a DHW distribution system.
Any other use shall be considered unsuitable and dangerous for people, animals, and/or property.
The equipment shall be installed in compliance with the prevailing standards and in accordance with the manufacturer's instructions specified
in this manual: the manufacturer will not be held responsible for injuries to people and animals and/or damages to property resulting from
an incorrect installation.
Damage and/or injury caused by incorrect installation or use and/or damage and/or injury due to non-observance of the manufacturer’s
instructions shall release the manufacturer from any and all contractual and extra-contractual liability.
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.
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 specific waste management
sites.
After removing the packaging, make sure that its elements (clips, plastic bags, foam polystyrene etc.) are note left within the reach of children
as they are potential hazard sources.
In the event of failure and/or faulty functioning, switch off the boiler. Do not attempt to make repairs: contact qualified technicians.
Original parts must be used for all repairs to the boiler.
Non-observance of the above requirements may affect 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.
WARNING
The boiler must be serviced periodically as indicated in the relevant section of this manual.
Appropriate boiler maintenance ensures efficient 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 qualified personnel, satisfying all prevailing law requirements, 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. The electronic
antifreeze function will not be operative with the device disconnected from the electric power supply and gas cock closed.
Should there be a risk of freezing, add antifreeze: it is not advisable to drain the system as this may result in damage;use specific anti-freeze
products suitable for multi-metal heating systems.
DANGER
With gas fired boilers, take the following measures if you smell gas:
• Do not turn on or off electric switches and do not turn on electric appliances.
• Do not ignite flames and do not smoke.
• Close the main gas cock.
• Open doors and windows.
• Contact a Service Centre, a qualified installer or the gas supply company.
Never use a flame to locate a gas leak.
The boiler is designed for installation in the countries indicated on the technical data plate: 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.

4
Rapid operating instructions
The following instructions will help you to switch the boiler on quickly and regulate it for immediate use.
WARNING
It is presumed that the boiler has been installed by a qualified installer, it has been commissioned and is ready to operate correctly.
If any accessories have been fitted on the boiler, these instructions will not cover them. You will therefore have to refer to the full
boiler instructions as well as to the specific instructions for the accessories.
This manual contains full details of how the boiler works, and full operating and safety instructions.
1. Open the gas cock installed ahead of the boiler.
2. Turn the master switch installed ahead of the boiler ON; the boiler display turns on.
3. If you do not wish to activate the CH function, press the button until displaying the symbol : only the
DHW function will be enabled.
4. If you wish to activate both the heating and DHW functions, press the button until displaying the symbol
.
5. If you do not wish to activate the DHW function, press the button until displaying the symbol : only
the CH function will be enabled.
6. To set the domestic hot water temperature, press DHW +/- buttons.
7. To set the heating water temperature, press CH +/- buttons.
8. Set the desired temperature on the (optional) ambient thermostat in the building. The boiler is now ready to
operate.
If the boiler shuts down, press button
If boiler does not resume its operation after three attempts, contact a qualified Service Centre.

5
1. Instructions for the user .......................................................... 8
1.1 Control panel....................................................................................................................................................................................... 8
1.2 Interpreting boiler status from display indications.................................................................................................................... 10
1.3 Selecting the operating mode......................................................................................................................................................... 11
1.4 Adjusting heating and DHW temperature ................................................................................................................................... 12
1.5 Parameter display .............................................................................................................................................................................. 12
1.6 Failures that cannot be reset ........................................................................................................................................................... 13
1.7 Resume boiler function ..................................................................................................................................................................... 13
1.8 Boiler operation .................................................................................................................................................................................. 14
1.9 Boiler shut-down ................................................................................................................................................................................ 17
1.10 Maintenance ....................................................................................................................................................................................... 20
1.11 Notes for the user................................................................................................................................................................................ 20
2. Technical features and dimensions................................................. 21
2.1 Technical features .............................................................................................................................................................................. 21
2.2 Dimensions .......................................................................................................................................................................................... 23
2.3 Boiler layouts....................................................................................................................................................................................... 26
2.4 Operating data ................................................................................................................................................................................... 29
2.5 General characteristics...................................................................................................................................................................... 30
2.6 ERP and Labelling data..................................................................................................................................................................... 33
3. Instructions for the installer ....................................................... 41
3.1 Installation standards....................................................................................................................................................................... 41
3.2 Choosing where to install the boiler.............................................................................................................................................. 41
3.3 Positioning the boiler ........................................................................................................................................................................ 42
3.4 Installing the boiler ............................................................................................................................................................................ 43
3.5 Boiler room ventilation ..................................................................................................................................................................... 43
3.6 Air intake and flue gas venting system ......................................................................................................................................... 44
3.7 Checking combustion efficiency..................................................................................................................................................... 51
3.8 Connection to gas mains.................................................................................................................................................................. 52
3.9 Hydraulic connections ...................................................................................................................................................................... 53
3.10 Connection to electrical mains ....................................................................................................................................................... 54
3.11 Connection to ambient thermostat (optional) ........................................................................................................................... 55
3.12 Installation and operation with Open Therm Remote Control (optional) ........................................................................... 55
3.13 TSP parameters................................................................................................................................................................................... 58
3.14 TSP parameters................................................................................................................................................................................... 58
3.15 Filling the system................................................................................................................................................................................ 64
3.16 Starting up the boiler......................................................................................................................................................................... 65
3.17 Available head .................................................................................................................................................................................... 65
3.18 Wiring diagrams................................................................................................................................................................................. 67
3.19 Adaptation to other gas types and burner adjustment............................................................................................................ 79
4. Testing the boiler................................................................ 83
4.1 Preliminary checks ............................................................................................................................................................................. 83
4.2 Switching on and switching off ...................................................................................................................................................... 83
5. Maintenance ................................................................... 84
5.1 Maintenance schedule...................................................................................................................................................................... 84
5.2 Combustion analysis......................................................................................................................................................................... 84
6. Decommissioning, disassembly and disposal ........................................ 85
7. Malfunctions, possible causes and solutions ......................................... 86
7.1 Troubleshooting ................................................................................................................................................................................. 86

6
Fig. 1 Control panel ..............................................................................................................8
Fig. 2 Filler cock.................................................................................................................18
Fig. 3 Dimensions KC ...........................................................................................................23
Fig. 4 Dimensions KR............................................................................................................24
Fig. 5 Dimensions KRB ..........................................................................................................25
Fig. 6 Hydraulic diagram KC .....................................................................................................26
Fig. 7 Hydraulic diagram KR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Fig. 8 Hydraulic diagram KRB....................................................................................................28
Fig. 9 Paper template ...........................................................................................................42
Fig. 10 Installation examples ....................................................................................................45
Fig. 11 Coaxial ducts C33........................................................................................................49
Fig. 12 Coaxial ducts C33 distance specs.........................................................................................49
Fig. 13 Coaxial ducts C43 - C53 - C83 ............................................................................................51
Fig. 14 Coaxial ducts C43 - C53 - C83 dimensions ................................................................................51
Fig. 15 Plugs position ...........................................................................................................52
Fig. 16 Hole position............................................................................................................52
Fig. 17 Connection to gas mains.................................................................................................53
Fig. 18 Condensate drain........................................................................................................54
Fig. 19 Thermoregulation curves ................................................................................................58
Fig. 20 Available head KC-KR-KRB 12 ............................................................................................65
Fig. 21 Available head KC-KR-KRB 24 ............................................................................................66
Fig. 22 Available head KC-KR-KRB 28 ............................................................................................66
Fig. 23 Available head KC-KR-KRB 32 ............................................................................................66
Fig. 24 Wiring diagram KC.......................................................................................................67
Fig. 25 Wiring diagram for forced circulation solar system with combi boiler ......................................................69
Fig. 26 Multifunction relay connection diagram..................................................................................69
Fig. 27 Wiring diagram for natural circulation solar system with combi boiler .....................................................71
Fig. 28 Multifunction relay connecting diagram (Z = neutral; Y = to boiler; Z = to collector) ........................................71
Fig. 29 Wiring diagram KC model................................................................................................72
Fig. 30 Forced circulation solar system with CH only boiler wiring diagram........................................................74
Fig. 31 Multifunction relay connection diagram..................................................................................74
Fig. 32 Wiring diagram KRB model...............................................................................................75
Fig. 33 Relay with remote control and TA2 .......................................................................................77
Fig. 34 Relay with remote request (P17=1) .......................................................................................77
Fig. 35 Relay with TA2 request (P17 = 3) .........................................................................................78
Fig. 36 Intake pipe ..............................................................................................................80
Fig. 37 Mixer....................................................................................................................80
Fig. 38 Mixer plastic body .......................................................................................................81
Fig. 39 Assembling direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
Fig. 40 Adjusting CO2 value .....................................................................................................82

7
Tab. 1 Displayable parameters with info button..................................................................................12
Tab. 2 Adjustment specifications KC-KR-KRB 12 ..................................................................................29
Tab. 3 Adjustment specifications KC-KR-KRB 24 ..................................................................................29
Tab. 4 Adjustment specifications KC-KR-KRB 28 ..................................................................................29
Tab. 5 Adjustment specifications KC-KR-KRB 32 ..................................................................................29
Tab. 6 Model KC general data ...................................................................................................30
Tab. 7 Model KR/KRB general data...............................................................................................31
Tab. 8 KC-KR-KRB 12 combustion data ...........................................................................................32
Tab. 9 KC-KR-KRB 24 combustion data ...........................................................................................32
Tab. 10 KC-KR-KRB 28 combustion data..........................................................................................32
Tab. 11 KC-KR-KRB 32 combustion data..........................................................................................32
Tab. 12 ERP and Labelling data - KC 12...........................................................................................33
Tab. 13 ERP and Labelling data - KC 24...........................................................................................34
Tab. 14 ERP and Labelling data - KC 28...........................................................................................35
Tab. 15 ERP and Labelling data - KC 32...........................................................................................36
Tab. 16 ERP and Labelling data - KR/KRB 12 ......................................................................................37
Tab. 17 ERP and Labelling data - KR/KRB 24 ......................................................................................38
Tab. 18 ERP and Labelling data - KR/KRB 28 ......................................................................................39
Tab. 19 ERP and Labelling data - KR/KRB 32 ......................................................................................40
Tab. 20 Boiler re-ignition temperature ...........................................................................................55
Tab. 21 Limits to be set for TSP parameters and default values in relation to boiler type (TSP0).....................................56
Tab. 22 List of parameters - I.....................................................................................................59
Tab. 23 List of parameters - II ....................................................................................................60
Tab. 24 Solar parameter (with P17=2 or with supplementary board) ..............................................................61
Tab. 25 Display only ............................................................................................................62
Tab. 26 System check ...........................................................................................................63
Tab. 27 Parameter setting .......................................................................................................78
Tab. 28 Relationship between "Temperature and Nominal resistance" for temperature probes.....................................78
Tab. 29 Flue CO2 content .......................................................................................................82
Tab. 30 Diameter of nozzles - diaphragms (mm) .................................................................................82

8Instructions for the user
1. Instructions for the user
1.1 Control panel
8
7
6
5
4
3
2
1
E BDCA
9
10
11
12
13
14
Fig. 1 Control panel
A. DHW setting (+/- DHW).
B. CH water temperature (+/- CH) and parameter settings.
C. Alarm reset and back to the starting page during parameter selection.
D. Parameter confirmation and information request.
E. Operating status selection.
Touch the display in order to activate it. Unless an operation is performed, the display deactivates after 15 seconds.

9
Instructions for the user
Ref. Symbol Steady on Flashing
1Percentage indication Not used
2Indication of "parameter" inside the
parameter menu Not used
3
Displaying of the number of parameters,
or of the system pressure, or of the
burner power percentage
Not used
4Indication of system pressure
measurement unit Not used
5Displaying of temperature, parameter
values and faults. Not used
6Indication of the centigrade degrees Not used
7A DHW request is present Displaying of the DHW temperature
set-point
8A heating request is present Displaying of the heating temperature
set-point
9
Symbols for instantaneous DHW,
heating.
ON = function enabled;
Symbol off = function disabled.
Not used
10 Not used Displaying of the fictitious ambient
temperature set-point
11 Solar pump or solar valve active Not used
12
Displaying of the flue cleaning function
and of the "rpm" wording to show the
number of revolutions per minute of
the fan.
Indicates that you are accessing the flue
cleaning function.
13
During parameter setting, the 'wrench'
symbol stays on until the value is
confirmed.
Not used
14 Lit flame indication Not used

10 Instructions for the user
1.2 Interpreting boiler status from display indications
1.2.1 Normal operation
Boiler switch in OFF mode.
Boiler switch in SUMMER or WINTER or CH ONLY mode
No active function.
The flow temperature and the system pressure are displayed.
SUMMER WINTER CENTRAL HEATING ONLY
Boiler switch in SUMMER or WINTER mode
DHW function enabled.
The domestic hot water temperature and the modulation percentage
are displayed.
SUMMER WINTER
Boiler switch in WINTER or CH ONLY mode
CH function active.
The flow temperature and the modulation percentage are displayed.
WINTER CENTRAL HEATING ONLY
1.2.2 Malfunction
To identify any malfunctions, refer to paragraph Troubleshooting on page 86.

11
Instructions for the user
1.3 Selecting the operating mode
Whenever key is pressed, the "SUMMER”, “WINTER” ,“CH ONLY”, “OFF”modes are enabled in sequence.
At this stage, all buttons are enabled.
1. "OFF" operating status
When the "OFF" mode is enabled, no function is active.
2. "SUMMER" operating status
When the "SUMMER" mode is enabled, only the DHW production function is active.
3. "WINTER" operating status
When the "WINTER" mode is enabled, both DHW and CH functions are active.
4. "CH ONLY" operating status
When the "CH ONLY" mode is enabled, only the heating water production function is active.

12 Instructions for the user
1.4 Adjusting heating and DHW temperature
Press button +/- DHW to select the desired DHW temperature.
During selection, icon will flash.
In the phase in which the icon is flashing, only the buttons to adjust the temperature are enabled.
As soon as button is released, icon will continue flashing for approx. 3 seconds, and temperature value will flash as
well.
After this time, value is stored and display standard operation will be restored.
Press CH +/- button to select the desired flow water temperature.
During selection, icon will flash.
In the phase in which the icon is flashing, only the buttons to adjust the temperature are enabled.
As soon as button is released, icon will continue flashing for approx. 3 seconds, and temperature value will flash as
well.
After this time, value is stored and display standard operation will be restored.
1.5 Parameter display
Press to scroll the different parameter values.
You can quit this function at any time by simply pressing the button.
To find the meaning of all parameters, see TSP parameters on page 58 59.
Par. DESCRIPTION
P30 - TSP30 external temperature displayed (if an external probe is installed).
P31 Flow temperature is displayed.
P32
Calculated nominal flow temperature is displayed. If an external probe is not installed the flow temperature manually set
on the boiler is displayed. If an external probe is installed the flow temperature automatically set by the boiler on the basis
of the thermoregulation curves is displayed.
P42 Domestic hot water temperature displaying (on KC models, only).
P43 Boiler return temperature displaying.
P44 Water heater temperature displaying (for KR and KRB models with installed water heater probe).
P45 Flue gas temperature displaying.
P46 Solar collector temperaturedisplaying (if the collector probe is installed on the boiler).
P47 Solar water heater temperature or solar valve temperature displaying (if the water heater probe or solar valve probe are
installed on the boiler).
P48 Solar water heater temperature or solar valve temperature displaying (if the water heater probe or solar valve probe are
installed on additional solar board).
Tab. 1 Displayable parameters with info button

13
Instructions for the user
1.6 Failures that cannot be reset
The display shows the failure based on the corresponding error code (see Troubleshooting on page 86).
Some failures can be reset through the key, while some others are self-resettable (refer to the following
paragraph).
If failures cannot be reset but are of the self-resettable type, no key will be enabled and only the LCD backlighting
will be on.
As soon as the error cause is eliminated, the failure signal will disappear from the interface.
The interface is enabled and after 15 seconds is disabled, unless a button is pressed.
1.7 Resume boiler function
The display shows the failure based on the corresponding error code (see Troubleshooting on page 86).
Some failures can be reset through the key, while some others are self-resettable.
If shutdowns can be reset (E01, E02, E03, E40), the reset key and the LCD backlighting will always be on.
The only active key you can press is the key.
When the reset key is pressed and boiler is under the correct conditions, the error is reset. The failure signal will
disappear from the interface.
The interface is enabled and after 15 seconds is disabled, unless a button is pressed.

14 Instructions for the user
1.8 Boiler operation
1.8.1 Switching on
DANGER
It is presumed that the boiler has been installed by a qualified installer, it has been commissioned and is ready to operate correctly.
• Open the gas shut-off 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 10).
• Select boiler operating mode by pressing button on the touch-screen: OFF, SUMMER, WINTER, CH ONLY (see Selecting the operating
mode on page 11).
• Set desired CH temperature (see CH function on page 14).
• Set desired DHW temperature (see DHW function on page15).
• Set the desired room temperature on the ambient thermostat inside the home (if installed).
WARNING
Should the boiler be left inactive for a long time, particularly when boiler is propane-fired, ignition might be difficult.
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 difficulties and shut down once or
twice. Press the RESET button to restore boiler operation.
1.8.2 CH function
To set the heating water temperature, press +/- 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 a installer or an authorized Service Centre (see par. Selecting the operating range in heating
mode on page 55).
During temperature setting, the symbol flashes on the screen and the CH current temperature setting is displayed.
When the CH system requests heat from the boiler, the LCD displays the CH symbol and the current CH flow water temperature.
The waiting time between one boiler ignition and the following one, used to prevent boiler frequent turning on and off, ranges between 0 and
10 minutes (default value: 4 minutes), 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.

15
Instructions for the user
1.8.3 DHW function
DHW production function is enabled on model KC and on KR/KRB models with external water heater (optional).
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 flashes on the screen and the DHW current temperature setting is displayed.
Model KC
For KC model, DHW temperature may be set within a range from +35 °C to +57 °C.
WARNING
A flow limiter is installed within the boiler, which limits DHW output flow rate.
This limit value is: 10 litres per minute for KC 12 model; 13 litres per minute for KC 24 model, 14 litres per minute for KC 28 model,
and 16 litres per minute for KC 32 model.
Models KR/KRB
On KR/KRB models with external water heater (optional) and water heater temperature probe
(optional, supplied by the manufacturer; included in the standard supply for KRB model),
temperature range is between 35 °C and 65 °C.
On KR/KRB models with external water heater (optional) and water heater probe (optional, supplied by the manufacturer), every 15 days
the anti-legionella function will be enabled, consisting in raising the water heater temperature to 65°C for 30 minutes independent of other
settings.
1.8.4 Freeze protection function
This boiler is fitted 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 effectively protected against icing by using specific anti-freeze products that are suitable for multi-metal
systems.
WARNING
Do not use anti-freeze products for car engines, and check the effectiveness 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.
1.8.4.1 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.

16 Instructions for the user
1.8.4.2 Plate heat exchanger freeze protection (only model KC)
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 flow probe is constantly checked, and in case it reaches +60 °C
the burner is switched off.
The burner is switched on again if the operation request in anti-freeze mode is still present and the flow temperature is below +60°C.
The pump continues to operate even if the boiler shuts down.
1.8.4.3 Water heater freeze protection function (for models KR/KRB with external water heater).
The water cylinder probe measures the temperature of water in the cylinder. When this temperature is less than 5°C a water heater frost
protection function begins: the circulating pump begins working and the burner is switched on.
On KR/KRB models with external water cylinder (optional) with NTC probe (10 kΩ @ ß=3435; refer to water cylinder technical specifications),
the frost protection function also protects the water heater.
When water heater probe detects a water temperature of +5 °C, the boiler switches on and stays on at its minimum heat output until the
temperature of the water heater water reaches +10 °C or 15 minutes have elapsed.
The pump continues to operate even if the boiler shuts down.
During the water heater anti-freeze operation the temperature detected by the flow probe is constantly checked, and in case it reaches +60°C
the burner is switched off.
The burner is switched on again if the operation request in anti-freeze mode is still present and the flow temperature is below +60°C.
1.8.5 Anti-seize function
If the boiler remains inactive and connected to the power mains, the circulation pump and the deviating valve (if any) 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 deviating valve.

17
Instructions for the user
1.8.6 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.
When working with an external probe, the CH +/- buttons are no longer used to set heating water temperature, but to edit fictitious ambient
temperature, namely the desired theoretical temperature.
During temperature setting, the fictitious ambient temperature symbol flashes 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 "cruising temperature operation", refer to paragraph Installation of the (optional) external probe and sliding temperature
operation on page 57.
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 affect the operation of the external probe itself
and of the boiler.
1.8.7 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 and (optional) external water heater 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 page55.
WARNING
Only use original Remote Control Units supplied by the manufacturer.
The use of non-original remote controls, not supplied by the manufacturer, may affect Remote Control and boiler operation.
1.9 Boiler shut-down
The boiler shuts down automatically if a malfunction occurs.
To determine the possible causes of malfunction (see Troubleshooting on page 86).
Below is a list of shut-down types and the procedure to follow in each case.

18 Instructions for the user
1.9.1 Burner shut-down
Fault code E01 is displayed flashing on the display in the event of burner shut-down due to missing flame.
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 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 qualified personnel for maintenance.
WARNING
If the burner shuts down frequently, there is a recurring malfunction, so contact a service centre or a qualified service engineer.
1.9.2 Shut-down due to overheating
Fault code E02 is shown on the LCD display in the event of flow water temperature overheating. Contact a service centre or a qualified service
engineer to carry out the maintenance.
1.9.3 Shut-down due to incorrect air/flue gas system draught
If the air/flue gas system malfunctions, the boiler shuts down and the code E03 is displayed flashing on the display. (triggering of flue gas
thermostat).
Contact a service centre or a qualified service engineer to carry out the maintenance.
1.9.4 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 filler 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 filler cock anticlockwise to allow water to enter the boiler;
• Keep the filler cock open until the pressure gauge shows a value of 1÷1.3 bar;
• Turn cock clockwise to close it.
Should boiler shuts down frequently occur it means there is boiler malfunction in progress. Contact qualified personnel or an authorised
service centre for maintenance.
DANGER
Make sure you close filler cock (A) carefully after filling procedure is completed.
If the filler cock is not correctly closed, when the pressure increases, error E09 may be displayed and the heating system safety
valve may activate and discharge water.
AAA
KC KRB
KR
Fig. 2 Filler cock

19
Instructions for the user
1.9.5 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 for the CH probe: in this case the boiler does not work.
• E06 for the DHW probe (KC model, only); in this case, the boiler works in central heating mode only, and the DHW function is disabled.
• E12 for the water heater probe (KR/KRB models only); in this case, the boiler works in central heating mode only, and the water hjeater
heating function is disabled.
• E15 for the return probe; iIn this case the boiler does not work.
WARNING
In any case, contact a service centre or qualified personnel for maintenance.
1.9.6 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 qualified service engineer to carry out the maintenance.
The remote control can indicate faults or shutdown conditions and can also restore boiler operation after shutdown 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 re-connect again boiler from/to power mains.
1.9.7 Shut-down for fan malfunction
The fan operation is constantly monitored and in case of malfunction the burner goes off; the code E40 flashes 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 qualified service engineer.
1.9.8 Alarm due to (optional) external temperature probe malfunction
In case of external temperature probe failure, boiler will continue to operate, but the "sliding temperature" operation will be disabled.
Heating water temperature is adjusted based on the value set with CH +/- buttons that, in this case, are no longer used to adjust calculated
ambient temperature.
Contact a service centre or a qualified service engineer.

20 Instructions for the user
1.10 Maintenance
WARNING
The boiler must be serviced periodically as indicated in the relevant section of this manual.
Appropriate boiler maintenance ensures efficient operation, environment preservation, and safety for people, animals and objects.
Boilers must be maintained by qualified personnel only, under the requirements set forth by the prevailing rules.
1.11 Notes for the user
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 qualified 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.
If the boiler remains inactive and the power supply is switched off for a long time, it may be necessary to reset the pump.
This involves removing the casing and accessing internal parts, so it must only be carried out by suitably qualified personnel.
Pump failure can be avoided by adding to the water filming additives suitable for multi-metal systems.