Beretta Mynute LOW NOx 24 C.S.I. Manual De Instalacion Y Uso página 6

ENGLISH
mestic hot water, according to the current request. During burner
ignition following a pre-heating request, the monitor indicates the
symbol (fig. 7a).
To deactivate the pre-heating function, rotate the domes-
tic hot water temperature adjustment knob back to the
symbol. Bring the domestic hot water temperature adjustment
knob back to the required position. This function cannot be acti-
vated when the boiler is OFF: function selector (8a) on
Adjustment of central heating temperature
To adjust central heating temperature, turn the knob
se within the area marked + and - (fig. 2a)
Adjustment of domestic hot water temperature
To adjust domestic water temperature (bathrooms, showers, kitch-
en, etc.), turn the knob with symbol
marked + and -.
The boiler is standby status until, after a heat request, the burner
switches on and the digital display shows the hot water system
temperature, the icon to indicate the hot water supply and the flame
icon.
The boiler will be in function until the adjusted temperature is
reached, afterwards it will be in "standby" again.
Environment Automatic
(S.A.R.A.) fig. 11a
By setting the heating water temperature selector to the area
marked by AUTO - temperature value from 55 to 65°C - the
S.A.R.A. self-adjusting system is activated: the boiler varies the
delivery temperature according to the closing signal of the room
thermostat. When the temperature set with the heating water tem-
perature selector is reached, a 20 minutes count begins. If during
this period the room thermostat still requests heat, the value of the
set temperature automatically increases by 5 °C.
When the new value is reached, other 20 minutes count begins.
If during this period the room thermostat still requests heat, the
value of the set temperature automatically increases by 5 °C.
This new temperature value is the result of the temperature set
manually with the heating water temperature selector and the in-
crease of +10 °C of the S.A.R.A function. After the second cycle the
temperature value should be kept at the set value +10°C until the
request of the room thermostat is satisfied.
4.3 Switching off
Temporary switching off
In case of absence for short periods of time, set the mode selector
(8a) to (OFF).
In this way (leaving the electricity and fuel supplies enabled), the
boiler is protected by the following systems:
- Anti-frost device: when the temperature of the water in the boiler
falls below 5°C, the circulator and, if necessary, the burner are
activated at minimum output levels to bring the water tempera-
ture back to the values for safety (35°C). During the anti-frost
cycle, the symbol appears on the digital monitor (fig. 9a)
- Circulator anti-blocking function: an operation cycle is activated
every 24 hours.
- DHW Antifreeze (only when connected to an external storage
tank with probe): the function is activated if the temperature mea-
sured by the storage tank probe drops below 5° C. A heat re-
quest is generated in this phase with the ignition of the burner at
minimum power, which is maintained until the water temperature
reaches 55° C. During the anti-frost cycle, the symbol
on the digital monitor.
Long period switching off
In case of absence for long periods of time, set the mode selector
(8a) to (OFF).
Then, close the gas tap present on the system. In this case, anti-frost
device is deactivated: empty the systems, in case of risk of frost.
4.4 Light signals and faults
The operating status of the boiler is shown on the digital display,
below is a list of the types of displays fig. 10a)
To restore operation (deactivate alarms):
Faults A 01-02-03
6
(fig. 2a) within the area
Adjustment System Function
Position the function selector to
set it to the required position
mode). If the reset attempts do not reactivate the boiler, contact the
Technical Assistance Centre.
Fault A 04
In addition to the fault code, the digital display shows the symbol .
Check the pressure value indicated by the water gauge:
OFF.
if it is less than 0.3 bar, position the function selector to
and adjust the filling tap (B fig. 20) until the pressure reaches a
value between 1 and 1.5 bar.
Then position the mode selector to the desired position
clockwi-
mer) or (winter).
If pressure drops are frequent, request the intervention of the Tech-
nical Assistance Service.
Fault A 06
The boiler operates normally but cannot reliably maintain a con-
stant domestic hot water temperature, which remains set at around
50°C. Contact the Technical Assistance Centre.
Fault A 07
Contact the Technical Assistance Centre.
BOILER STATUS
Stand-by
OFF status
ACF module lockout alarm
ACF electrical fault alarm
Limit thermostat alarm
Air pressure switch alarm
H2O pressure switch alarm
NTC domestic water fault
NTC heating fault
Parasite flame
Electric calibration min and max heating
Transient awaiting ignition
Air pressure switch intervention
Fumes thermostat intervention
H2O pressure switch intervention
Preheating Function active
Preheating heat request
External probe present
Domestic water heat request
Heating heat request
Anti-freeze heat request
Flame present
4.5 Adjustments
The boiler has already been adjusted by the manufacturer.
If it is necessary to adjust it again, for example after extraordinary
maintenance, after replacement of gas valve or after gas conver-
sion, carry out the following procedure.
The maximum output adjustment must be carried out in the
appears
sequence indicated exclusively by qualified personnel.
- remove the shell unscrewing the fixing screws A (fig. 13)
- unscrew by two turns the screw of the pressure test point down-
stream the gas valve and connecting the pressure gauge
- disconnect the compensation inlet of the air distribution box
4.5.1 Maximum power and minimum domestic hot water
adjustment
- Fully open the hot water tap
- on the control panel:
- set the mode selector to
- turn the domestic hot water temperature selector to its maximum
(fig. 8a)
(OFF), wait 5-6 seconds then
(summer mode) or
DISPLAY
-
OFF
A01
A01
A02
A03
A04
A06
A07
A11
ADJ
88°C
flashing
flashing
flashing
flashing
60°C
80°C
(summer) (fig. 2a)
(winter
(OFF)
(sum-