Fondital KR 55 Instructions for use

IST 03 C 351 - 01
INSTALLATION
USE AND MAINTENANCE
TAHITI CONDENSING
KR 55 - KR 85
GB

2
Dear Customer,
Thank you for choosing and buying one of our boilers. Please read these instructions carefully. They will enable you to install, operate,
and service the appliance properly.
Any maintenance and repairs must be carried out by fully qualied engineers who carry the appropriate competency for this equipment.

3
General information for tters, maintenance technicians and users
This INSTRUCTION MANUAL, which is an integral and indispensable part of the product, must be handed over to the user by the installer and must
be kept in a safe place for future reference. The manual must accompany the boiler should it be sold or its possession transferred. Following to the
boiler installation, the tter is to advise the user about boiler operation and its safety devices.
This boiler is designed for connection to a domestic heating or hot water system.
Any other use is deemed as improper and as such dangerous. Under no circumstances will the manufacturer be held
responsible for damage or injury to persons or animals caused by errors in the installation and/or use of the appliance, or
through non-compliance with current local and national standards and/or the manufacturer’s instructions.
The boiler must be installed by qualied personnel, in compliance with applicable laws and standards and according to the manufacturer’s
instructions given in this manual.
Before installing the boiler, check that the technical data corresponds 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 damaged and/or
faulty. In case of doubt, do not attempt to use the product but refer to the supplier.
Do not obstruct the air intake or ue exhaust grids and terminals.
Only manufacturer approved and supplied parts or optional kits (including electric ones) must be used for all repairs to the boiler.
Packing materials (cardboard box, wooden crate, nails, staples, plastic bags, polystyrene, etc.) must not be left within reach of children in that these
items represent a potential hazard and must be disposed of in a responsible manner.
Properly dispose of the packaging as all the materials can be recycled. The packaging must therefore be sent to specic waste management sites.
In the event of failure and/or malfunction, shut down the system. Do not interfere with or attempt any repairs. Call for professionally qualied
technical assistance only.
Failure to comply with the above requirements may aect the safety of the boiler and endanger people, animals and property.
Before carrying out any cleaning or maintenance operations, disconnect the appliance from the mains electricity supply by switching o at the
main switch and/or any other isolating device.
In order to guarantee ecient and correct operation of the equipment, the manufacturer recommends that the boiler be
serviced and repaired by a Service Centre.
Routine boiler maintenance is to be performed according to the schedule 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 or irregular maintenance can cause a hazard for people, animals and property.
In the event of long periods of inactivity of the boiler, disconnect it from power mains and close the gas tap. Warning!
When power mains are disconnected, boiler electronic anti-freeze function will not be operative.
Should there be a risk of freezing, add anti-freeze: it is not advisable to empty the system as this may result in damage; use specic anti-freeze
products suitable for multi-metal heating systems.
It is not advisable to empty the system as this may result in damage.
Should 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 tap;
- open doors and windows;
- contact a Service Centre, a qualied installer or the gas supply company.
Never use ames to detect gas leaks.
The boiler is designed for installation in the country indicated on the technical data plate: installation in any other country may
be source of danger for people, animals and objects.
The Manufacturer cannot be held contractually or extra-contractually liable in the event of failure to comply with the above.

4
TABLE OF CONTENTS
General information for tters, maintenance technician and user
page
3
1. User instructions page 6
1.1. Control panel page 6
1.2. LCD page 7
1.3. Boiler status – Message display page 8
1.4. Operating the boiler page 9
1.4.1. Switching on the boiler page 9
1.4.2. CH function page 9
1.4.3. DHW function page 9
1.4.4. ANTI-FREEZE function page 10
1.4.5. PUMP ANTI-SEIZE function page 10
1.4.6. Operation with Remote Control (optional) page 10
1.4.7. Operation with an external probe (optional) page 11
1.5. Boiler lockout page 12
1.5.1. Burner lockout page 12
1.5.2. Lockout due to overheating page 12
1.5.3. Lockout due to air/ue gas system malfunction page 12
1.5.4. Lockout due to a water circulation malfunction page 12
1.5.5. Lockout for fan malfunction page 13
1.5.6. Alarm due to temperature probe malfunction page 13
1.5.7. Alarm due to (optional) remote control connection malfunction page 13
1.5.8. Alarm due to (optional) external probe malfunction page 13
1.6. Maintenance page 13
1.7. Notes for the user page 13
2. Technical features and dimensions
page
14
2.1. Technical features page 14
2.2. Dimensions of the KR 55 page 15
2.3. Dimensions of the KR 85 page 16
2.4. Main components for the KR 55 page 17
2.5. Main components for the KR 85 page 18
2.6. Operating data page 19
2.7. General characteristics page 19
2.8. Pumping head page 20
3. Instructions for the tter
page
21
3.1. Installation standards page 21
3.2. Installation page 21
3.2.1. Packaging page 21
3.2.2. Choosing where to install the boiler page 21
3.2.3. Positioning the boiler page 21
3.2.4. Installing the boiler page 23
3.2.5. Boiler room ventilation page 23
3.2.6. Air intake and ue gas discharge system page 24
3.2.6.1. Conguration of air intake and ue gas discharge pipes page 25
3.2.6.2. Air intake and ue gas discharge conguration – model KR 55 page 26
3.2.6.3. Air intake and ue gas discharge conguration – model KR 85 page 26
3.2.7. Testing combustion eciency page 27
3.2.7.1. Chimney-sweep function page 27
3.2.7.2. Measurement procedure page 28
3.2.8. Connecting to the gas mains page 28
3.2.9. Plumbing connections page 29
3.2.10. Power mains connection page 29
3.2.11. Selecting the CH operating range page 30
3.2.12. Connecting the ambient thermostat (optional) page 30
3.2.13. Connecting the OpenTherm remote control (optional) page 30
3.2.14. Connecting to the external probe (optional) and sliding temperature operation page 31
3.3. Filling the system page 33
3.4. Starting the boiler page 33
3.4.1. Preliminary checks page 33
3.4.2. Switching on and o page 33
3.5. Wiring diagrams page 34
3.6. Adapting to other gases and regulating the burner page 37
3.6.1. Switching from METHANE to PROPANE page 37
3.6.2. Switching from PROPANE to METHANE page 37
3.6.3. Regulating the burner page 37
4. Commissioning the boiler page 38
4.1. Preliminary checks page 38
4.2. Switching on and o page 38
5. Maintenance
page
39
5.1. Maintenance schedule page 39
5.2. Combustion analysis page 39
6. Troubleshooting
page
40

5
LIST OF FIGURES
pic. 1 - Control panel page 6
pic. 2 - LCD page 7
pic. 3 - Calculated ambient temperature regulation page 11
pic. 4 - Thermoregulation curves page 11
pic. 5 - Filling tap page 12
pic. 6 - KR 55 Dimensions page 15
pic. 7 - KR 85 Dimensions page 16
pic. 8 - Main components of the KR 55 page 17
pic. 9 - Main components of the KR 85 page 18
pic. 10 - Head curves to the KR 55 system page 20
pic. 11 - Head curves to the KR 85 system page 20
pic. 12 - Installation template page 22
pic. 13 - Installation examples page 24
pic. 14 - Boiler casing opening page 27
pic. 15 - Chimney-sweep function page 27
pic. 16 - Air intake and ue gas discharge tower page 28
pic. 17 - Openings for combustion eciency measurement page 28
pic. 18 - Gas mains connection page 28
pic. 19 - Thermoregulation trimmer page 32
pic. 20 - Central heating curves with external probe operation page 32
pic. 21A - Wiring diagram for KR 55 page 34
pic. 21B - Wiring diagram for KR 85 page 35
pic. 22 - Adaptation to other gas types for KR 55 page 37
pic. 23 - Adaptation to other gas types for KR 85 page 37
pic. 24 - Gas valve regulation for KR 55 page 37
pic. 25 - Gas valve regulation for KR 85 page 37
LIST OF TABLES
Table 1 - Boiler Status-Message Display with normal operation page 8
Table 2 - Boiler status-Message display with malfunction page 8
Table 3 - Calibration data for KR 55 page 19
Table 4 - Calibration data for KR 85 page 19
Table 5 - General specications page 19
Table 6 - Combustion data for KR 55 page 19
Table 7 - Combustion data for KR 85 page 19
Table 8 - Burner ignition temperatures page 30
Table 9 - Limit values for TSP parameters and default values for each boiler type (TSP0) page 31
Table 10 - Displayable TSP parameters (not modiable from remote control) page 31
Table 11 - Relation between temperature and nominal resistance of the temperature probe page 36
Table 12 - CO2 rates page 37

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1. User instructions
1.1. Control panel
1. Liquid crystal display (LCD)
The LCD displays the boiler status and operating data (pic. 2).
2. Boiler function selector
With the selector on RESET , the boiler restarts after activation of the burner shutdown device (lockout).
With the selector on OFF, the boiler is in stand-by mode, with the heating and hot water functions disabled.
With the selector on SUMMER , the boiler is ready to produce domestic hot water only, provided it is connected to a separate water heater. If the
boiler is not connected to a separate water heater, this position is equivalent to ANTI-FREEZE .
With the selector on WINTER , the boiler is ready for both heating and domestic hot water production. Hot water is only provided if the boiler is
connected to a separate water heater.
With the selector on ANTI-FREEZE , only the anti-freeze function is enabled; the CH and DHW functions are disabled.
3. DHW temperature regulator
If the boiler is connected to a separate water heater, this regulator is used to switch the water heater on and o.
If the water heater has an NTC probe (10 kΩ @ ß=3435; check the water heater technical data), this is used to regulate the DHW temperature in the
range 35-65°C.
If the boiler is not connected to a separate water heater, this regulator has no eect on boiler operation.
4. CH water temperature regulator
This is used to select the temperature of the water in the heating system in the range 20-45°C or 20-78°C.
5. Water pressure gauge
This shows the pressure of the water in the primary system.
pic. 1
1 2 3 4 5

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1.2. LCD
a. DHW indicator
This indicator only activates if the boiler is connected to a separate water heater.
This comes on when the boiler is in DHW mode.
It ashes when the DHW temperature is being regulated via regulator 3(pic. 1).
b. Water heater on indicator
This indicator only activates if the boiler is connected to a separate water heater.
This indicator comes on when the water heater (optional) is activated via regulator 3(pic. 1).
c. Alphanumeric indicator
This shows the following:
- CH ow water temperature
- CH temperature setting
- DHW temperature setting (if the boiler is connected to a separate water heater).
- boiler status
- boiler diagnostics
d. Central heating indicator
This comes on when the boiler is in CH mode.
It ashes when the CH temperature is being regulated via regulator 4(pic. 1).
e. Boiler shutdown indicator
This comes on when there is a malfunction that cannot be reset via the boiler funtion selector 2(pic. 1).
The problem must be solved before the boiler can be restarted.
f. Burner shutdown indicator
This comes on when the burner shutdown device activates due to a malfunction.
To restart the boiler, turn the boiler selector 2 (pic. 1) to the RESET position for a few seconds and then back to the desired position.
g. Flame indicator
This comes on when the burner ame is present.
h. Chimney-sweep function indicator (for tter only)
This ashes when the chimney-sweep function is activated.
The ow water temperature and the number of fan revs are shown alternatively (in this case, symbol mis also shown)
i. Thermoregulation indicator (for tter only)
This comes on when the thermoregulation curve is set.
l. Calculated ambient temperature indicator
When an external probe is installed, this indicator ashes when the calculated ambient temperature is set via regulator 4.
m. Number of fan revs (for tter only)
When the chimney-sweep function is activated, symbol hashes and ow water temperature and number of fan revs are shown alternatively (in
this case, the correspondent symbol is also shown).
pic. 2
a b c d
e
f g h i l
m

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1.3. Boiler status – Message display
Normal operation
Boiler selector on OFF
Boiler selector on ANTI-FREEZE
Boiler selector on SUMMER or WINTER
No function active
The ow water temperature is displayed
Boiler selector on SUMMER or WINTER
DHW system enabled (*)
The ow water temperature is displayed
Boiler selector on WINTER
CH function active
The ow water temperature is displayed
Boiler selector on SUMMER or WINTER
Water heater enabled, no function active (*)
The ow water temperature is displayed
Table 1 – Boiler Status - Message Display with normal operation
(*) If the boiler is connected to a separate water heater.
Malfunction
Boiler not powered on
Boiler lockout due to ame absence
Boiler lockout due to safety thermostat activation
Boiler lockout due to ue gas thermostat activation
CH probe failure
Water heater probe fault
Only if the boiler is connected to a separate water heater (optional) with an NTC temperature
probe 10 kΩ @ ß=3435 (check the water heater technical data)
Low primary uid circulation alarm
(pump ON – ow switch OPEN)
Low primary uid circulation alarm
(pump OFF – ow switch CLOSED)
Fan failure
Remote control connection failure
External probe failure
Table 2 - Boiler status - Message display with malfunction

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1.4. Operating the boiler
1.4.1. Switching on the boiler
The following procedure is to be implemented only after the boiler has been installed and commissioned by a qualied tter.
- Open the gas stop cock.
- Turn ON the master switch external to the boiler; the LCD shows and indicates the active function (see Table 1).
- Select boiler operation mode via selector 2(pic. 1): OFF/SUMMER/WINTER/ANTI-FREEZE.
- Set the desired CH temperature (§ 1.4.2.).
- If the boiler is connected to a separate water heater, set the desired DHW temperature (§ 1.4.3.).
- Set the desired ambient temperature by means of the ambient thermostat in the premises (optional).
IMPORTANT
When starting up the boiler for the rst time or it has not been used for a long period of time, particularly when it is propane-red,
ignition may be dicult and the boiler may shut down a few times.
Resume boiler operation by turning selector 2 (pic. 1) to the reset position for a few seconds then back to the desired position.
If the boiler still does not ignite after several attempts, it needs to be serviced by a Service Centre or a qualied service engineer.
1.4.2. CH function
Set the desired CH water temperature on knob 4(pic. 1).
The CH water temperature range depends on the selected operating range:
- standard range: from 20°C to 78°C (from full anticlockwise to full clockwise position).
- reduced range: from 20°C to 45°C (from full anticlockwise to full clockwise position).
The temperature range must be set by the tter or a Service Centre (§ 3.2.11).
During temperature setting, the CH symbol on the LCD ashes and the CH setting is displayed.
When the CH system requests heat, the LCD shows the (stable) CH symbol and the CH water temperature.
The burner symbol only shows when the burner is in operation.
To prevent the boiler from switching on and o frequently in CH mode, it is tted with an anti cycling device with
a delay time between subsequent ignitions, which depends on the selected operating range:
- standard range: 4 minutes;
- reduced range: 2 minutes.
Should the water temperature in the system fall below the default value (§ 3.2.11.), the delay time is zeroed and the boiler re-ignited.
1.4.3. DHW function
Domestic hot water function is only enabled if the boiler is connected to a separate water heater (optional).
The DHW function operates on temperature and always has priority over the CH heating function.
Enabling/disabling the water heater
The separate water heater (optional) can be enabled or disabled via knob 3.
If the water heater active symbol is not displayed, turn knob 3fully anticlockwise and the symbol will appear.
Then turn it clockwise until a temperature of at least 40°C is displayed.
To disable the water heater, turn knob 3fully anticlockwise until the symbol disappears and then clockwise until a
temperature of at least 40°C is displayed.
When you turn knob 3, the DHW symbol ashes on the display.

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Regulating the DHW temperature
If the water heater has an NTC probe (10 kΩ @ β=3435; check the water heater technical data), the temperature
setting range is 35-65°C (from the fully anticlockwise to the fully clockwise position on knob 3). During
temperature setting, the DHW symbol ashes on the display and the DHW temperature setting is displayed.
It is advisable to set a temperature of at least 40°C to allow the system to operate eciently.
If the water heater has a thermostat probe, the DHW temperature must be set on the water heater (check the water heater technical data). Knob 3
has no eect on this conguration, except to enable/disable the water heater as described above.
With the water heater enabled, it is always advisable to set knob 3 to at least 40°C.
When the DHW system requests water, the LCD shows the DHW symbol (stable) and the instant CH water
temperature.
The burner symbol only shows when the burner is in operation.
1.4.4. ANTI-FREEZE function
The boiler is tted with an anti-freeze protection system, which works when the following functions are enabled: SUMMER, WINTER and ANTI-
FREEZE.
When the CH temperature sensor measures 5°C, the boiler switches on and stays at the minimum heat output until it reaches 30°C or 15 minutes
have elapsed. The pump continues to operate even if the boiler shuts down.
Anti-freeze function protects the boiler only, not the entire CH system.
The CH system must be protected by other methods, depending on the type of installation.
The CH system can be protected eectively against freezing by means of specic anti-freeze additives suitable for use in multi-metal systems.
It is important to check the eectiveness of the anti-freeze product periodically.
Do not use car engine anti-freeze products.
If the boiler is connected to a separate water heater with an NTC probe (10 kΩ @ β=3435; check the water heater handbook), when the probe
measures a temperature of 5°C in the water heater, the boiler switches on and stays at the minimum heat output until it reaches 10°C or 15 minutes
have elapsed. The pump continues to operate even if the boiler shuts down.
If the boiler is connected to a separate water heater with a thermostat, the anti-freeze function does not protect the water heater. In this case, to
protect the water heater, you need to turn knob 3on the boiler to WINTER and set a DHW water temperature on the water heater higher than 0 °C.
If the boiler shuts down, the heater is not protected against freezing.
1.4.5. PUMP ANTI-SEIZE function
If:
- the boiler remains inactive for more than 24 hours,
- selector 2(pic. 1) is NOT in the OFF position, or
- the boiler is still connected to the mains supply,
the pump activates for 30 seconds to keep it ecient.
1.4.6. Operation with Remote Control (optional)
The boiler can be connected to an (optional) remote control, which can be used for setting numerous parameters, including:
- boiler status
- ambient temperature
- CH water temperature
- CH water temperature
- DHW water temperature (only if the boiler is connected to a separate water heater (optional) with an NTC temperature probe 10 kΩ @ ß=3435
(NTC probe order code: 0KITSOND00);
- switching on times for the CH system and water heater;
- boiler diagnostics display
- boiler reset
and others.
For instructions on how to connect the remote control, refer to § 3.2.13.

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IMPORTANT
Once the remote control has been installed, turn selector 2 on the boiler (pic. 1) to WINTER.
CH and DHW functions can be enabled and disabled via the remote control.
Correct operation of the boiler and remote control are NOT guaranteed if selector 2 on the boiler is left on a position other than WINTER.
Selector 2 on WINTER
Only original remote controls supplied by the manufacturer must be used.
If non-original remote controls are used, correct operation of the boiler and the remote control cannot be guaranteed.
1.4.7. Operation with an external probe (optional)
The boiler can be connected to an external temperature probe (optional).
When the external temperature has been measured, the boiler automatically regulates the CH water temperature, increasing it when the outside
temperature drops and decreasing it when it rises, which improves comfort and saves fuel (this is referred to as “sliding temperature operation”).
The CH water temperature varies according to a program in the boiler’s microprocessor.
When an external probe is installed, knob 4(pic. 1) loses its CH water temperature function and becomes a calculated ambient temperature
regulator (pic. 3) for the temperature desired in the rooms to be heated.
During temperature setting, the calculated ambient temperature symbol ashes and the temperature
setting is displayed.
Knob 4in the fully anticlockwise position corresponds to a calculated ambient
temperature of 15°C, 9 o’clock corresponds to 18°C, 12 o’clock to 25°C, 3 o’clock
to 32°C and the fully clockwise position to 35°C.
To get an optimal curve, a setting of approximately 20°C is recommended.
Figure 4 shows the curves for a calculated ambient temperature of 20°C.
If the value is increased or decreased via knob 4, the curve shifts up and down, respectively, by the same
amount.
With this setting, for example, if you select the curve corresponding to parameter 1 and the outdoor temperature is -4°C, the ow temperature will
be 50°C.
For details on sliding temperature operation mode, refer to § 3.2.14.
Only original external probes supplied by the manufacturer must be used.
If non-original external probes are used, correct operation of the boiler and the probe cannot be guaranteed (external probe
order code: 0SONDAES01).
pic. 3
15 35
32
25
18
pic. 4 Outside temperature (°C)
Flow temperature (°C)

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1.5. Boiler lockout
The boiler locks out down automatically if a malfunction occurs.
Refer to Tables 1 and 2 to identify the boiler operating mode.
Refer to Table 2 and section 6 to identify possible causes of the shutdown. The troubleshooting section is at the end of this manual.
Below is a list of possible causes of the shutdown and the procedure to follow in each case.
1.5.1. Burner lockout
If the burner locks out down as there is no ame, the burner shutdown symbol is displayed and code E01
ashes. 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;
• if the gas supply is normal, turn selector 2(pic. 1) to the reset position for a few seconds, then back to the desired position. If after three
attempts the burner still fails to ignite, contact a Service Centre or a qualied service engineer.
If the burner locks out frequently, there is a recurring malfunction, so contact a Service Centre or a qualied service engineer.
1.5.2. Lockout due to overheating
If the water temperature is too high, the boiler will lock out. The burner lockout symbol is displayed and code
E02 ashes.
Contact a Service Centre or a qualied service engineer.
1.5.3. Lockout due to air/ue gas system malfunction
If the air/ue gas system malfunctions, the boiler locks out. The burner lockout symbol is displayed and code
E03 (ue gas thermostat) ashes.
Contact a Service Centre or a qualied service engineer.
1.5.4. Lockout due to a water circulation malfunction
If the pressure or water circulation in the heating system are incorrect, the boiler locks out. The boiler lockout symbol is displayed and codes
E10 or E26 ash, according to the malfunction.
With code E10 ashing there can be two dierent situations:
a) the pressure gauge (5, pic. 1) shows a pressure lower than 1 bar
Proceed as follows to restore the correct water pressure:
• Turn the external lling tap (pic. 5) anticlockwise to allow water to enter the boiler.
• Keep the tap open until the pressure gauge shows a value of 1-1.3 bar.
• Turn the tap clockwise to close it.
• Wait a minute until the malfunction disappears from the display.
If the boiler still fails to operate, contact a Service Centre or a qualied service engineer.
Make sure you close the external lling tap carefully after lling.
If you do not, when the pressure increases, the safety valve may activate and discharge.
b) the pressure gauge (5, pic. 1) shows a pressure of 1-1.3 bar
Contact a Service Centre or a qualied service engineer.
2. With ashing code E26, contact a Service Centre or a qualied service engineer.
pic. 5 Filling tap

13
1.5.5. Lockout for fan malfunction
Fan operation is constantly monitored and in case of a malfunction it goes o; the boiler lockout symbol is
displayed and code E17 ashes.
This mode is maintained until the fan recovers normal working parameters.
If the boiler should not start and remain in this mode, contact a Service Centre or a qualied service engineer.
1.5.6. Alarm due to temperature probe malfunction
If the burner locks out due to malfunction of the temperature probes, the boiler lockout symbol is displayed and the following codes may ash:
• E05, CH probe: the boiler does not work;
• E12, for the heater probe (if the boiler is connected to an external optional water heater tted with NTC 10 kΩ @ß=3435 temperature probe): the
boiler operates in CH mode only.
If the boiler is connected to an external optional water heater tted with a temperature thermostat, the boiler electronics do not detect possible
thermostat malfunctions.
Contact a Service Centre or a qualied service engineer.
1.5.7. Alarm due to (optional) remote control connection malfunction
The boiler recognises whether or not there is a remote control (optional). If the remote control is connected but
the boiler does not receive instructions, the boiler lockout symbol is displayed and code E22 ashes.
The boiler will continue to operate according to the settings on the control panel (pic. 1) and ignore the remote control settings.
Contact a Service Centre or a qualied service engineer.
1.5.8. Alarm due to (optional) external probe malfunction
If the (optional) external temperature probe malfunctions, the boiler lockout symbol is displayed and code
E23 ashes.
The boiler will continue to operate, but the sliding temperature function is disabled. The temperature of the
CH water is regulated according to the position of regulator 4(pic. 1), which in this case loses its function as a calculated ambient temperature
regulator (see 1.4.7.).
Contact a Service Centre or a qualied service engineer.
1.6. Maintenance
The boiler must be serviced periodically as indicated in the relevant section of this manual.
Correct maintenance of the boiler will allow it to work eciently, without harming the environment, and in complete safety.
Maintenance and repairs must be performed by qualied personnel.
The user is strongly advised to have the boiler serviced and repaired by a fully qualied Service Centre.
Refer to section 5 for Maintenance instructions.
The end user may clean the case of the appliance using a proprietary cleaning solution applied to the cloth, not directly to the boiler
surface. Do not use water.
1.7. Notes for the user
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 cannot be held liable for damage or injury due to tampering of the boiler or improper intervention.
If the boiler remains inactive and the power supply is switched o 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 qualied personnel.
Pump failure can be avoided by adding proprietary central heating system additives.

14
2. Technical features and dimensions
2.1. Technical features
The boiler is equipped with a fully pre-mixed gas burner. All models are equipped with electronic ignition and an ionization ame sensing device.
The following models are available:
KR 55: condensing boiler with sealed chamber and forced draught, supplying CH water, 55kW
KR 85: condensing boiler with sealed chamber and forced draught, supplying CH water, 85kW
The boilers meet applicable laws in force in the country of destination, which is stated on the rating plate.
If the boiler is installed in a country other than the one specied, it may be dangerous for people, animals and objects.
The main technical features of the boilers are listed below:
Construction features
• IPX4D electrically protected control panel
• Integrated, electronic safety and modulation board
• Electronic ignition via separate igniter and ionization ame detection
• Stainless steel, fully pre-mixed burner
• Stainless steel mono-thermal, high-eciency heat exchanger with
deaerator
• Twin shutter, modulating gas valve with constant air/gas ratio
• Electronically-controlled modulating ue gas discharge fan
• Three-speed pump with built-in deaerator
• Air separator with deaerator
• Dierential pressure switch, preventing incorrect water circulation in
the CH system
• Minimum ow switch detecting no water in the CH system
• CH temperature probe
• Safety thermostat
• Flue gas thermostats
• Filling tap
User interface
• Liquid crystal display showing the boiler operating status
• Mode selector: OFF, RESET, WINTER, SUMMER and ANTI-FREEZE
• CH water temperature regulator: 20-78°C (standard range) or 20-45°C
(reduced range)
• DHW water temperature regulator: 35-65°C (if the boiler is connected
to a separate water heater)
• Water pressure gauge
Operating features
• Electronic ame modulation in CH mode with timer-controlled rising
ramp (50 seconds)
• Flow anti-freeze function: ON at 5°C; OFF at 30°C or after 15 minutes of
operation if CH temperature >5°C
• Water heater anti-freeze function (if the boiler is connected to a
separate water heater): ON at 5°C; OFF at 10°C or after 15 minutes of
operation
• Anti-legionella function (if the boiler is connected to a separate water
heater with an NTC 10 kΩ @ ß=3435 probe)
• Timer-controlled chimney-sweep function: 15 minutes
• Ignition ame propagation function
• Timer-controlled ambient thermostat: 240 seconds with ow
temperature >40°C
• Pump post-circulation function in CH, anti-freeze and chimney-sweep
modes
• Post-ventilation safety function: ON at 95°C, OFF at 90°C
• Pump anti-seize function: 30-second operation after 24 hours of boiler
inactivity
• Provision for connection to a ambient thermostat (optional)
• Provision for operation with an external probe (optional, supplied by
the manufacturer)
• Provision for operation with an OpenTerm remote control (optional,
supplied by the manufacturer)

15
2.2. Dimensions of the KR 55
pic. 6
SCondensate drain
CI Water mains intake (1/2’’)
GGas inlet (3/4’’)
SI Condensate trap
FCH system ow (1’’)
RC Filling tap
RCH system return (1’’)
450
750 3050
43 56 173 98 80
220.5
12762
14813589 78
534
S
SI
G
MF
R
RC
Aspirazione aria
scarico fumi
Ø 100/60 mm
Aspirazione aria
Ø 80 mm
View from below View from above
Ø 100/60 mm
air intake/ue gas outlet
Ø 80 mm
air intake
CI
F

16
2.3. Dimensions of the KR 85
750
450
50 42
89 135 148 78
12762
534
43 56 173 98 80
220.5
S
SI
G
MF
R
RC
Scarico fumi
Ø 100 mm
Aspirazione aria
Ø 80 mm
pic. 7
SCondensate drain
CI Water mains intake (1/2’’)
GGas inlet (3/4’’)
SI Condensate trap
FCH system ow (1’’)
RC Filling tap
RCH system return (1’’)
View from below View from above
Ø 100 mm
ue gas outlet
Ø 80 mm
air intake
CI
F

17
2.4. Main components for the KR 55
pic. 8
1
12
3
9
8
18
16
10
2
19 20
7
5
6
11
13
17
15
14
4
21
1 Control panel
2 Heat exchanger
3 Flue gas fan
4 Air separator
5 Deaerator on heat exchanger
6 CH temperature probe
7 Flue gas thermostat
8 Inspection plug on condensate trap
9 Condensate drain pipe
10 Pre-mixing burner
11 Dierential pressure switch
12 Gas valve
13 Safety thermostat
14 Circulating pump
15 Deaerator on air separator
16 Ignition electrode
17 Detection electrode
18 Air/gas mixer
19 Air/ue gas test intake
20 Air/ue gas suction tower
21 Minimum water pressure switch

18
2.5. Main components for the KR 85
pic. 9
1
9
12
4
15
14
13
17
11
6
5
7
19
2
16
10
18
8
3
20
1 Control panel
2 Heat exchanger
3 Flue gas fan
4 Air separator
5 Deaerator on heat exchanger
6 CH temperature probe
7 Flue gas thermostat
8 Inspection plug on condensate trap
9 Condensate drain pipe
10 Pre-mixing burner
11 Dierential pressure switch
12 Gas valve
13 Safety thermostat
14 Circulating pump
15 Deaertator on air separator
16 Ignition electrode
17 Detection electrode
18 Air/gas mixer
19 Flue gas outlet
20 Minimum water pressure switch

19
2.6. Operating data
Burner pressures must be veried after a three minute boiler operation time.
KR 55
Fuel type
Max. CH
input
[kW]
CH
output
(80-60°C)
[kW]
CH
output
(50-30°C)
[kW]
Gas mains
pressure
[mbar]
Diaphragm
diameter
[mm]
Flue gas
CO2
[%]
min max min max
Methane Gas G20 55.0 14.1 53.5 15.7 58.8 20 8.2 8.8 ÷ 9.1
Propane Gas G31 55.0 14.1 53.5 15.7 58.8 37 5.9 9.8 ÷ 10.1
Table 3 – Calibration data for KR 55
KR 85
Fuel type
Max. CH
input
[kW]
CH
output
(80-60°C)
[kW]
CH
output
(50-30°C)
[kW]
Gas mains
pressure
[mbar]
Diaphragm
diameter
[mm]
Flue gas
CO2
[%]
min max min max
Methane Gas G20 85.0 20.3 82.7 22.6 90.4 20 10.3 8.8 ÷ 9.1
Propane Gas G31 85.0 20.3 82.7 22.6 90.4 37 7.9 9.8 ÷ 10.1
Table 4 – Calibration data for KR 85
2.7. General characteristics
KR 55 KR 85
Category - II2H3P II2H3P
CH minimum pressure bar 0.5 0.5
CH maximum pressure bar 5 5
CH maximum working temperature °C 83 83
DHW maximum working temperature (*) °C 65 65
Methane gas consumption at max. ow (**) m3/h 5.82 9.00
Propane gas consumption at max. ow kg/h 4.26 6.59
Power supply (voltage ~ frequency) V ~ Hz 230 ~ 50 230 ~ 50
Maximum input power W 245 245
Index of protection IP X4D X4D
Table 5 – General specications
(*) If the boiler is connected to a separate water heater with NTC probe 10 kΩ @ ß=3435
(**) Value referred to 15 °C - 1013 mbar
KR 55 Pmax Pmin 30% heat output
Casing heat loss with burner on % 0.46 0.83 -
Casing heat loss with burner o % 0.36
Chimney heat loss with burner on % 2.04 1.89 -
Flue gas system mass ow rate g/s 25.1 6.6 -
Flue gas - air temperature °C 44 39 -
Available pumping head Pa 290 23 -
Maximum heat output eciency rating (60/80°C) % 97.3 - -
Maximum heat output eciency rating (30/50°C) % 107.0 - -
Minimum heat output eciency rating (60/80°C) % - 97.0 -
Minimum heat output eciency rating (30/50°C) % - 108.1 -
30% heat output eciency rating % - - 108.9
Eciency rating (according to 92/42/CEE) -
NOXemission class - 5
Table 6 – Combustion data for KR 55
KR 85 Pmax Pmin 30% heat output
Casing heat loss with burner on % 0.30 0.93 -
Casing heat loss with burner o % 0.48
Chimney heat loss with burner on % 2.20 1.79 -
Flue gas system mass ow rate g/s 38.7 9.6 -
Flue gas - air temperature °C 47 36 -
Available pumping head Pa 240 19 -
Maximum heat output eciency rating (60/80°C) % 97.3 - -
Maximum heat output eciency rating (30/50°C) % 106.4 - -
Minimum heat output eciency rating (60/80°C) % - 97.3 -
Minimum heat output eciency rating (30/50°C) % - 107.7 -
30% heat output eciency rating % - - 108.5
Eciency rating (according to 92/42/CEE) -
NOXemission class - 5
Table 7 – Combustion data for KR 85

20
2.8. Pumping head
pic. 10
pic. 11
V1
V2
V3
V1 Pump speed I (min)
V2 Pump speed II
V3 Pump speed III (max)
V1
V2
V3
V1 Pump speed I (min)
V2 Pump speed II
V3 Pump speed III (max)
Flow rate (l/h)
Flow rate (l/h)
Available head (mbar) Available head (mbar)
KR 55
KR 85
With ow rates less than 1600 l/h correct boiler operation is not guaranteed. If
lesser ow rates are required it is necessary to install an hydraulic separator.
With ow rates less than 2350 l/h correct boiler operation is not guaranteed. If
lesser ow rates are required it is necessary to install an hydraulic separator.