Nova Florida DELFIS Monothermal Quick start guide

DELFIS
Monothermal
INSTALLATION, USE AND MAINTENANCE
EN
Translation of the
original instructions (in
Italian)
IST 04 C 404 - 01

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
In existing buildings, this natural draught boiler must be connected only to ue pipes shared by several houses to vent the
combustion residues outside the premises inside which boiler is installed.
Boiler takes the air necessary to combustion directly from the installation premises and features a wind-proof ue.
Due to a lower eciency, any other use of this boiler must be avoided as it would result in a higher energy consumption and higher
operating costs.
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.
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 specied
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 specic 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 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.
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 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 specic anti-freeze
products suitable for multi-metal heating systems.

4
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: 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.

5
1. Instructions for the user .......................................................... 8
1.1 Control panel....................................................................................................................................................................................... 8
1.2 Interpreting boiler status from display indications.................................................................................................................... 10
1.3 Boiler operation .................................................................................................................................................................................. 11
1.4 Boiler shut-down ................................................................................................................................................................................ 14
1.5 Maintenance ....................................................................................................................................................................................... 16
1.6 Notes for the user................................................................................................................................................................................ 16
2. Technical features and dimensions................................................. 17
2.1 Technical features .............................................................................................................................................................................. 17
2.2 Dimensions .......................................................................................................................................................................................... 19
2.3 Boiler layouts....................................................................................................................................................................................... 20
2.4 Operating data ................................................................................................................................................................................... 21
2.5 General characteristics...................................................................................................................................................................... 21
2.6 ERP and Labelling data..................................................................................................................................................................... 22
3. Instructions for the installer ....................................................... 23
3.1 Installation standards....................................................................................................................................................................... 23
3.2 Choosing where to install the boiler.............................................................................................................................................. 23
3.3 Positioning the boiler ........................................................................................................................................................................ 24
3.4 Installing the boiler ............................................................................................................................................................................ 25
3.5 Air intake and ue gas venting system ......................................................................................................................................... 25
3.6 Checking combustion eciency..................................................................................................................................................... 28
3.7 Connection to gas mains.................................................................................................................................................................. 28
3.8 Hydraulic connections ...................................................................................................................................................................... 29
3.9 Connection to electrical mains ....................................................................................................................................................... 29
3.10 Connection to ambient thermostat (optional) ........................................................................................................................... 30
3.11 Installation and operation with Open Therm Remote Control (optional) ........................................................................... 30
3.12 TSP parameters................................................................................................................................................................................... 31
3.13 Filling the system................................................................................................................................................................................ 35
3.14 Starting up the boiler......................................................................................................................................................................... 36
3.15 Available head .................................................................................................................................................................................... 36
3.16 Wiring diagram................................................................................................................................................................................... 37
3.17 Adaptation to other gas types and burner adjustment............................................................................................................ 39
4. Testing the boiler................................................................ 41
4.1 Preliminary checks ............................................................................................................................................................................. 41
4.2 Switching on and switching o ...................................................................................................................................................... 41
5. Maintenance ................................................................... 42
5.1 Maintenance schedule...................................................................................................................................................................... 42
5.2 Combustion analysis......................................................................................................................................................................... 43
6. Decommissioning, disassembly and disposal ........................................ 43
7. Malfunctions, possible causes and solutions ......................................... 44
7.1 Troubleshooting ................................................................................................................................................................................. 44

6
Fig. 1 Control panel..............................................................................................................8
Fig. 2 Filler cock.................................................................................................................15
Fig. 3 Model CTN dimensions ...................................................................................................19
Fig. 4 Boiler layout CTN .........................................................................................................20
Fig. 5 Paper template ...........................................................................................................24
Fig. 6 Connections to the chimney of open chamber models .....................................................................27
Fig. 7 Dimensions for connection to the ue gas system of the open chamber models ............................................27
Fig. 8 Connection to gas mains..................................................................................................28
Fig. 9 Thermoregulation curves .................................................................................................34
Fig. 10 Available head...........................................................................................................36
Fig. 11 Wiring diagram CTN .....................................................................................................37
Fig. 12 SIT 845 ..................................................................................................................40

7
Tab. 1 Adjustment specications ................................................................................................21
Tab. 2 General specications ....................................................................................................21
Tab. 3 CTN 24 combustion specications ........................................................................................22
Tab. 4 ERP and Labelling data ...................................................................................................22
Tab. 5 Limits to be set for TSP parameters and default values in relation to boiler type (TSP0) - I ...................................31
Tab. 6 Limits to be set for TSP parameters and default values in relation to boiler type (TSP0) - II ...................................32
Tab. 7 Relationship between "Temperature and Nominal resistance" for temperature probes......................................38

8Instructions for the user
1. Instructions for the user
1.1 Control panel
2
1
10
5
6
8 7
C DB
A F G
9
3 4
E
Fig. 1 Control panel
A. DHW setting (+/- DHW).
B. Parameter conrmation and information request.
C. Operating status selection.
D. Alarm reset and back to the starting page during parameter selection.
E. LCD display.
F. CH water temperature (+/- CH) and parameter settings.
G. Heating system water pressure gauge.

9
Instructions for the user
Ref. Description Steady on Flashing
1
Flue cleaning function
indicator
(for the installer)
Flue cleaning function active. Indicates that you are accessing the ue
cleaning function.
2 DHW indicator Boiler is in DHW mode. Displaying of the DHW temperature set-
point.
3 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.
4 Alphanumeric indicator Temperature, parameter values and fault
indication. Not used.
5 Central heating indicator Boiler is in heating mode. Displaying of the heating temperature set-
point.
6Fictitious ambient
temperature indicator Not used. Displaying of the ctitious ambient temperature set-point.
7 Boiler status indicator DHW and/or heating function active. Not used.
8 Flame lighting indicator Lit ame indication. Not used.
9 Parameter code indicator Displaying of the number of parameters or
of the burner power percentage. Not used.
10 Parameter indicator Indication of "parameter" inside the
parameter menu. Not used.

10 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 44.

11
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 10).
• Select the boiler operating mode: OFF/SUMMER/WINTER/CH ONLY (see button (C) in Fig. 1 Control panel on page 8).
• Set desired CH temperature (see CH function on page 11).
• Set desired DHW temperature (see DHW function on page 12).
• Set the desired room temperature on the ambient thermostat inside the home (if installed).
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 COperating 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 heating water temperature, press +/- CH buttons.
The CH temperature setting range is from +35 °C to +78 °C.
During temperature setting, the symbol ashes 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 ow water temperature.
The waiting time between one boiler ignition and the following one, used to prevent boiler frequent turning on and o, 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 35°C and 78°C (default value 40°C) 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.

12 Instructions for the user
1.3.4 DHW function
Boiler electronics always gives priority to DHW over CH supply.
To set the domestic hot water temperature, press DHW +/- buttons.
The DHW temperature setting range is from +35 °C to +57 °C.
During temperature setting, the symbol ashes on the screen and the DHW current temperature setting is displayed.
The burner ON symbol shows while the burner is operating.
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 multi-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.
1.3.6 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.

13
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 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. The maximum temperature is respected all the same.
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 ctitious ambient
temperature, namely the desired theoretical temperature.
During temperature setting, the ctitious ambient temperature 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 "cruising temperature operation", refer to paragraph Installation of the (optional) external probe and sliding temperature
operation on page 33.
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.
1.3.9 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 page30.
WARNING
Only use original Remote Control Units supplied by the manufacturer.
The use of non-original remote controls, not supplied by the manufacturer, may aect Remote Control and boiler operation.

14 Instructions for the user
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 44).
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.
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/ue gas 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 E03 code.
To resume the operation press Reset (see Fig. 1 Control panel on page 8).
In case of repeated stops, it is necessary to have the boiler and the air intake/ue gas venting ducts checked by a service centre or a qualied
service engineer.

15
Instructions for the user
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 boiler shuts down frequently occur it means there is boiler malfunction in progress. Contact qualied personnel or an authorised
service centre for maintenance.
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.
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 for the CH probe: in this case the boiler does not work.
• E06 for the DHW probe; in this case, the boiler functions in central heating mode only, and the DHW function is disabled.
WARNING
In any case, contact a service centre or qualied personnel for maintenance.

16 Instructions for the user
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 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.
1.5 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 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.
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 to the water lming additives suitable for multi-metal systems.

17
Technical features and dimensions
2. Technical features and dimensions
2.1 Technical features
The boiler is equipped with an integrated gas atmospheric burner. The following models are available:
• CTN open chamber, natural draught boiler with electronic ignition for heating and instantaneous DHW supply.
The following power rates are available:
• CTN 24: with heat input of 24.5 kW
All models are equipped with electronic ignition and ionisation ame sensing 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 ignition and ionisation ame detection device.
• Stainless steel, atmospheric burner that can run on several gases.
• Mono-thermal, high performance, copper heat exchanger.
• Twin shutter modulating gas valve.
• High-eciency CH circulation pump with built-in air purging device.
• Safety pressure switch, preventing low water pressure operation.
• Flue gas thermostat
• Integrated, automatic by-pass.
• 7 litre expansion vessel.
• System water discharge tap.
• Heating ow water temperature probes.
• Stainless steel plate heat exchanger for DHW production.
• Motorised deviating valve.
• DHW priority ow switch.
• 10 litre/min DHW ow-limiting device.
• Domestic hot water temperature probe.
• System ller cock.
2.1.2 User interface
• Liquid crystal LCD interface showing the boiler operating status: OFF, SUMMER, WINTER and CH ONLY.
• CH water temperature setting buttons: 35-78 °C.
• DHW temperature setting buttons: 35-57 °C.
• System water pressure gauge.

18 Technical features and dimensions
2.1.3 Operating features
• Electronic ame modulation in CH mode, with timed rising ramp.
• Electronic ame modulation in DHW mode.
• Flow freeze protection function: ON 5°C; OFF 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.
• Ignition ame propagation function.
• CH thermostat timer: 240 seconds (adjustable).
• Heating pump post-circulation function in CH, freeze protection and ue cleaning modes: 30 seconds (adjustable).
• DHW post-circulation function: 30 seconds (adjustable).
• Post-circulation function for heating temperature > 78 °C: 30 seconds.
• Circulation pump and deviating valve anti shut-down function: 30 seconds of operation after 24 hours of inactivity.
• 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 OpenTherm remote control (optional, supplied by the manufacturer).
• Anti-water hammer function: can be set from 0 to 3 seconds.
• DHW function priority.

19
Technical features and dimensions
2.2 Dimensions
400
700
232
118
250
66 60 62 67 82 63
11431
91
81
M
C
G F
R
Fig. 3 Model CTN dimensions
MCH system ow - 3/4"
CDHW outlet - 1/2"
GGas inlet - 1/2”
FCold water inlet - 1/2"
RCH system return - 3/4”

20 Technical features and dimensions
2.3 Boiler layouts
Fig. 4 Boiler layout CTN
1. Automatic by-pass
2. DHW temperature probe
3. Motorised 3-way valve
4. Modulating gas valve
5. Burner
6. CH temperature double probe
7. Ignition/detection electrode
8. Mono-thermal heat exchanger
9. Flue gas thermostat
10. Expansion tank
11. 3-bar safety valve
12. Air-purging device
13. Minimum pressure switch
14. Circulation pump
15. 10 l/min ow-limiting device
16. Filler cock
17. Cold water ow switch with lter
18. Secondary plate exchanger
MCH system ow
AC DHW outlet
GGas inlet
AF Cold water inlet
RCH system return