27
6.3.4 Modulation based on boiler water temperature
The boiler is equipped with boiler water temperature sensor that allows it to modulate its power
according to the desired temperature.
To set water temperature, press button "1". Press button "1" once and the bottom of the display will
show the message " SET WATER TEMP", while the upper part of the display will show the set
water temperature. To modify this value, use buttons "1" and "2" until you reach desired
temperature (60°C to 80°C).
We recommend setting water temperature in the boiler at 70° C.
Briefly press button "4" to exit the programming or wait a few seconds to automatically return to the
work or stand-by position.
During the working phase, if the water temperature in the boiler is much lower than the set value,
the boiler operates at the maximum power level set.
However, when the boiler water temperature approaches the set value (difference of less than 4°
C), the boiler gradually decrements the power level. The last line of the display shows a flashing
number that indicates the power level at which the boiler is working at that moment. The more the
water temperature decreases the more the power level increases until it returns to the maximum
power value set initially.
We recommend always setting the boiler power to its maximum value
"5".
If, despite reducing power, boiler water temperature continues to rise and reaches the set
temperature, the bottom line of the display will show "MODULATE". If the water temperature tends
to rise further exceeding the set temperature by 8 °C the boiler goes in standby mode. The display
will show "WAITING FOR COOL.", during the final cleaning phase, and then "ECO STOP", during
the standby mode.
6.3.5 Circulator
This model has a circulator for direct connection of the system boiler to radiators. The circulator
starts as soon if the water in the boiler exceeds a temperature of 60° C (optimal value for this
model) and above this temperature it operates according to the temperature requested by the
external environment thermostat.
6.3.6 External thermostat
Boiler operation must be adjusted by an external room thermostat connected to the electronic
board (see wiring diagram). The thermostat connection is performed with a 2x0.5 mm
²
cable. The
contact to be used is NO (Normally open).
This operation should be performed by qualified
personnel.
A terminal board is found on the rear of the boiler to allow you make the desired connection (
see
picture 14
).
You may insert in parallel more than one external contact
(e.g. the contacts relative to two
different zone valves.)
If at least one external thermostat is active (contact closed), the boiler pump starts working,
powering the heating system and the temperature inside the boiler will start dropping until reaching
the
70°C
set restart threshold. When this threshold is reached, the boiler will light automatically in
order to deal with the system power request.
Once the system is satisfied, the external thermostat opens again and the pump will stop
immediately and as soon as the boiler temperature exceeds the threshold of
70°C
; the boiler will
modulate and will keep modulating until it reaches
78°C
, where the stand-by function will intervene,
shutting down the boiler.
Summary of Contents for Idro TERMOBOILER Mini Series
Page 10: ...10 2 5 Wiring diagram...
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