DOMINA C24 N / C28 N / C32 N
12
EN
cod. 3541E073 - Rev. 00 - 02/2014
Heating temperature adjustment
Use the knob (detail 1 - fig. 1) to adjust the temperature from a min. of 30°C to a max. of
80°C; in any case, it is advisable not to operate the boiler below 45°C.
DHW temperature adjustment
Use the knob (detail 2 - fig. 1) to adjust the temperature from a min. of 40°C to a maxi-
mum of 55°C.
Room temperature adjustment (with optional room thermostat)
Using the room thermostat, set the temperature desired in the rooms. If the room ther-
mostat is not installed the boiler will keep the heating system at its setpoint temperature.
Room temperature adjustment (with optional remote timer control)
Use the remote timer control to set the temperature desired in the rooms. The boiler au-
tomatically adjusts the temperature of the water in the heating system to suit the room
temperature setting. See the relevant user manual for details on how to opreate the re-
mote timer control.
A
If the boiler is connected to an optional remote timer control, heating system
and hot water temperature adjustments can only be made with the remote timer
control. Switching off the boiler, Summer/Winter mode switching and domestic
hot water disabling must still be done from the boiler's own control panel.
ECO/COMFORT selection
The unit is equipped with a special internal device that ensures a high hot-water delivery
speed and excellent user comfort. When the device is working (COMFORT mode), the
water in the boiler is kept at temperature, which means that hot water is available at the
boiler outlet as soon as a tap is opened, with no waiting.
This system may be disabled if required (ECO mode). To do so, press the ECO/COM-
FORT key while the boiler is in stand-by. In ECO mode the the yellow ECO LED lights
up. To turn on COMFORT mode, press the ECO/COMFORT button again. The yellow
ECO LED will go out.
Plumbing system pressure adjustment
The filling pressure read on the boiler water gauge with the system cold must be approx
1.0 bar If the system pressure falls to values below minimum, operate the filling cock (de-
tail 1 - fig. 3) and bring it to the initial value. Always close the filling cock at the end of the
operation.
fig. 3 - Filling cock (A=OPEN - B=CLOSED)
3. INSTALLATION
3.1 General Instructions
BOILER INSTALLATION MUST ONLY BE PERFORMED BY QUALIFIED PERSON-
NEL, IN ACCORDANCE WITH ALL THE INSTRUCTIONS GIVEN IN THIS TECHNICAL
MANUAL, THE PROVISIONS OF CURRENT LAW, THE PRESCRIPTIONS OF NA-
TIONAL AND LOCAL STANDARDS AND THE RULES OF PROPER WORKMANSHIP.
3.2 Place of installation
This unit is an
“open chamber”
type and can only be installed and operated in perma-
nently ventilated rooms. An insufficient flow of combustion air to the boiler will affect its
normal operation and fume evacuation. Also, the fumes forming under these conditions
are extremely harmful to health if dispersed in the domestic environment.
If equipped with the optional antiwind grille, the unit is suitable for use in a partially pro-
tected place in accordance with EN 297 pr A6, with minimum temperature of -5°C. It is
advisable to install the boiler under a roof slope, inside a balcony or in a protected recess.
Therefore the place of installation must be free of dust, flammable materials or objects
or corrosive gases.
The boiler is arranged for wall mounting and comes standard with a hooking bracket. Fix
the bracket to the wall according to the measurements given in fig. 8 and hook the boiler
onto it. Wall fixing must ensure a stable and effective support for the generator.
A
If the unit is enclosed in a cabinet or mounted alongside, a space must be pro-
vided for removing the casing and for normal maintenance operations.
3.3 Plumbing connections
Important
B
The safety valve outlet must be connected to a funnel or collection pipe to pre-
vent water spurting onto the floor in case of overpressure in the heating circuit.
Otherwise, if the discharge valve cuts in and floods the room, the boiler manu-
facturer cannot be held liable.
B
Before making the connection, check that the unit is arranged for operation with
the type of fuel available and carefully clean all the system pipes.
Carry out the relevant connections according to the diagram in fig. 12 and the symbols
on the unit.
Note:
The unit is equipped with an internal bypass in the heating circuit.
Water system characteristics
In the presence of water harder than 25° Fr (1°F = 10ppm CaCO
3
), use suitably treated
water in order to avoid possible scaling in the boiler.
Antifreeze system, antifreeze fluids, additives and inhibitors
When necessary, antifreeze fluids, additives and inhibitors can be used only if the man-
ufacturer of such fluids or additives guarantees that they are suitable and do not cause
damage to the exchanger or other components and/or materials of the boiler and system.
Do not use generic antifreeze fluids, additives or inhibitors that are not specific for use in
heating systems and compatible with the materials of the boiler and system.
3.4 Gas connection
The gas must be connected to the relevant connection (see fig. 12) in conformity with the
current standards, using a rigid metal pipe or a continuous surface flexible s/steel tube
and installing a gas cock between the system and boiler. Make sure all the gas connec-
tions are tight.
3.5 Electrical connections
Important
B
The unit must be connected to an efficient earthing system in conformity with
current safety regulations. Have the efficiency and suitability of the earthing
system checked by professionally qualified personnel; the Manufacturer de-
clines any liability for damage caused by failure to earth the system.
The boiler is prewired and provided with a "Y" type cable (without plug) for con-
nection to the electric line. The connections to the power supply must be per-
manent and equipped with a double-pole switch with contact opening distance
of at least 3 mm, installing fuses of max. 3A between the boiler and the line.
Make sure to respect the polarities (LINE: brown wire / NEUTRAL: blue wire /
EARTH: yellow/green wire) in connections to the electric line.
B
The unit's power cable must not be replaced by the user; if damaged, switch
the unit off and have the cable replaced by professionally qualified personnel.
If replacing the power cable, only use
"HAR H05 VV-F"
3x0.75 mm2 cable with
max. ext. diameter of 8 mm.
Room thermostat (optional)
B
IMPORTANT: THE ROOM THERMOSTAT MUST HAVE VOLTAGE-FREE
CONTACTS. CONNECTING 230 V TO THE ROOM THERMOSTAT TERMI-
NALS WILL PERMANENTLY DAMAGE THE ELECTRONIC BOARD.
When connecting time controls or a timer, do not take the power supply for
these devices from their breaking contacts Their power supply must be by
means of direct connection from the mains or with batteries, depending on the
kind of device.
Accessing the electrical terminal block
The electrical terminal block can be accessed after removing the casing. The arrange-
ment of the terminals for the various connections is also given in the wiring diagram in
fig. 20.
fig. 4 - Accessing the terminal block
2
1
A
B
72
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