Electric Connection; Preliminary Checks; Gas Connection - Beretta Mynute J 24 C.A.I. E Installer And User Manual

ENGLISH
3.2 Securing the boiler to the wall and hydraulic connections
To fasten the boiler to the wall, use the cardboard template (fig. 4-5) in the
packaging. The position and size of the hydraulic connections are indicated
below:
A CH return
B CH delivery
C

gas connection

D DHW output
E DHW input
In case of replacement of Beretta boilers from previous type, there is an adapta-
tion kit of hydraulic connections available.

3.3 Electric connection

The boilers leave the factory completely wired with the power cable already
connected and they only need the connection of the ambient thermostat (AT) to
be carried out in the specific terminals (page 89).
To access the terminal board:
- turn off the system general switch
- undo the fixing screws (A) of the shell (fig. 6)
- move forward and then upwards the shell base to unhook it from the
chassis
- undo the fixing screws (B) of the instrument panel (fig. 7)
- turn the instrument panel upside down
- remove the terminal board cover (fig. 8)
- insert the cable of the possible T.A. (fig. 9)
The ambient thermostat must be connected as indicated on the wiring diagram
on page 89.
Ambient thermostat input in safety low voltage (24 Vdc).
The connection to the mains supply must be carried out through a separation
device with omnipolar opening of at least 3.5 mm (EN 60335-1, category III).
The appliance operates with an alternating current of 230 Volt/50 Hz and an
electrical power of 85 W (and complies with the standard EN 60335-1 .
It is compulsory to carry out connection with an efficient earth circuit, ac-
cording to national and local legislation.
It is advisable to comply with neutral phase connection (L-N).
The earth wire must be a couple of centimetres longer than the
others.
Do not use gas and/or water pipes to earth electrical appliance.
The manufacturer declines liability for any damage if the appliance was not
connected to an earth circuit.
Use the power cable supplied to connect the boiler to the mains power
supply.
If the power cable is replaced, use a cable type HAR H05V2V2-F, 3 x 0.75
2
mm , with max. outside diameter 7 mm.
3.4 Gas connection
Before connecting the appliance to the gas network, check that:
- national and local regulations are complied
- the gas type is the one suitable for the appliance
- the piping is clean.
The gas pipe must be installed outdoor. If the pipe goes through the wall, it
must go through the central opening, in the lower part of the template.
It is advisable to install a filter of suitable dimensions on the gas line if the
distribution network had solid particles.
Once the appliance has been installed check that connections are sealed
according to current installation regulations
3.5 Fumes exhaustion and air suction
Observe applicable legislation regarding flue gas exhaustion. The exhaust
system must be made using rigid ducting, the joints between elements must be
hermetically sealed and all components must be resistant to heat, condensation
and mechanical stress and vibration. Non insulated outlet pipes are potential
sources of danger. The apertures for the combustion air must be realised
in compliance with applicable legislation (fig. 2). If condensation forms, the
exhaust duct must be insulated.
Figure 13 shows a top-down view of the boiler with the dimensions for the flue
gas exhaust outlet.
Flue gas safety system
The boiler features a system monitoring that flue gases are correctly exhausted
which arrests the boiler in the event of a fault: flue gas thermostat, fig. 11-12.
To restore normal operation, turn the function selector to "
few seconds, then turn the function selector into the desired position. If the
fault persists, call a qualified technical from the Technical Support Service. The
flue gas exhaustion monitoring system must never be bypassed or rendered
inoperable. Use only original replacement parts when replacing the whole
system or faulty system components.
4
3/4"
3/4"
3/4"
1/2"
1/2"
" (fig. 10), wait a
3.6 Filling the heating system (fig. 14)
Once the hydraulic connections have been carried out, fill the heating system.
This operation must be carried out with cold system following this instructions:
- turn by two or three turns the automatic relief valve cap (A)
- make sure the cold water inlet tap is open
- open the filling tap (B) until the pressure indicated by the water pressure gauge
is within 1 and 1.5 bar.
Once filling is complete, close the filling tap.
The boiler has an efficient air separator so no manual intervention is needed.
The burner switches on only if the air relief phase is finished.
3.7 Emptying the heating system
To empty the system, proceed as follow:
- switch off the boiler
- loose the boiler outlet tap (C)
- empty the lowest points of the system.
3.8 Emptying the domestic hot water
When there is risk of frost, the domestic hot water system must be emptied in
the following way:
- close the main tap of the water mains
- open all the hot and cold water taps
- empty the lowest points.
WARNING
When carrying out the discharge of the safety valve (D), it must be connected
to a suitable collection system. The manufacturer is not responsible for possible
damages due to safety valve operation.
4 IGNITION AND OPERATION

4.1 Preliminary checks

First ignition is carried out by competent personnel from an authorised
Technical Assistance Service Beretta.
Before starting up the boiler, check:
a) that the supply networks data (electric, water, gas) corresponds to the label
data
b) that piping leaving the boiler is covered by thermal insulation sheath
c) that flue gas extraction and air suction pipes work correctly
d) that conditions for regular maintenance are guaranteed if the boiler is placed
inside or between furniture
e) the seal of the fuel adduction system
f) that fuel capacity corresponds to values requested by the boiler
g) Check that the gas valve is calibrated correctly and, if necessary, adjust as
described in the paragraph "Adjustments"
h) that the gas supply system is of the correct capacity for the boiler and is
equipped with all the safety and monitoring devices prescribed by applicable
legislation.
4.2 Appliance ignition
To start-up the boiler it is necessary to carry out the following operations:
- power the boiler
- open the gas tap present in the system to allow fuel flow
- turn the mode selector (2 - fig. 1a) to the desired position:
summer mode: turning the selector to the symbol summer "
traditional function of only domestic hot water is activated. If there is a domestic
hot water request, the boiler switches on and the boiler status indicator LED (1)
lights up with a fixed green light. The digital monitor (5) indicates the domestic
hot water temperature (fig. 4a).
winter mode: turning the mode selector to the area divided in segments (fig.
2b) the boiler provides hot water and heating. If there is a heat request, the
boiler switches on and the boiler status indicator LED (1) lights up with a fixed
green light. The digital monitor (5) indicates the heating water temperature
(fig. 3a). If there is a domestic hot water request, the boiler switches on and
the boiler status indicator LED (1) lights up with a fixed green light. The digital
monitor (5) indicates the domestic hot water temperature (fig. 4a).
Pre-heating (faster hot water): rotate the domestic hot water temperature
adjustment knob (3 - fig. 1a) to the "
of the numbers between 1 (min. value 37°C) and 6 (max. value 60°C) (fig. 6a) to
activate the pre-heating function. This function keeps the water in the domestic
hot water exchanger hot, to reduce standby times when a request is made.
When the pre-heating function is enabled, the yellow LED (1) in line with the "
" symbol is ON. The monitor (5) indicates the delivery temperature of the
heating water or the domestic hot water, according to the current request. Dur-
ing burner ignition following a pre-heating request, the monitor indicates the "
" symbol. To deactivate the pre-heating function, rotate the domestic hot water
temperature adjustment knob back to the "
switch off. Bring the domestic hot water temperature adjustment knob back to
the required position. This function cannot be activated when the boiler is OFF:
function selector (2 fig.1a) on "
- Adjust ambient thermostat to desired temperature (~20°C)
Adjustment of the heating water temperature
To adjust the heating water temperature, turn the knob with symbol "
" (fig. 2a) the
" symbol, then rotate it in line with one
" symbol. The yellow LED will
" OFF.
" (fig.