Immergas EOLO Star Export Manual page 22

Technical documentation Technical documentation
Domestic hot water request
With the main switch (IG) in SUMMER or WINTER position, when the hot water microswitch (SS) is
closed, operation is enabled in hot water phase during which the circulator (MP) is not started or is
switched off in the event of heating type request under way.
Afterwards, the burner ignites in the same way as the heating phase.
During the heating phase, the current to the modulation coil is gradually raised in a time of 8 seconds
from minimum to a value equal to about 50% of maximum.
Subsequently, the signal is increased so as to immediately reach (if requested) the maximum value set on
the gas valve.
During operation, flame modulation occurs with reference to the difference between the temperature set
by means of the hot water potentiometer (SANIT) and the temperature read by the hot water sensor
(NS).
Once the set value is exceeded, the burner is kept operating at minimum hot water power (6,000
kcal/h) and the REQUEST RELAY contact is opened (burner off) only when the hot water sensor (NS)
reads a temperature above 65 ºC.
The burner is switched back on when the temperature falls to 64 ºC.
If during operation the C.H. sensor (NM) measures a temperature above 85 ºC, modulation (reduction of
burner power) occurs with reference to the temperature of the heating circuit and, in the event of this in
any case reaching 90°C, the burner is switched off and then back on when the temperature drops to 80
ºC.
The modulation range (maximum and minimum) during operation in hot water phase is adjusted
on the gas valve (see gas adjustments).
Heating antifreeze request
With the main switch (IG) in SUMMER or WINTER position, when the temperature read by the C.H.
NTC sensor (NM) falls below 4 ºC, the board triggers the generator in heating phase with burner at
minimum heating power (adjustment made with POT MIN RISC trimmer on adjustment board) until a
boiler temperature of 42°C is reached
Domestic hot water antifreeze request
With master switch (IG) in SUMMER or WINTER position, if the temperature read by the hot water
sensor (NS) falls below 4 ºC, the board triggers the generator in heating phase with burner at minimum
heating power (adjustment made with POT MIN RISC trimmer on adjustment board).
The burner is kept operating at minimum heating power until the hot water sensor (NS) reads a
temperature of 8 °C.
During operation, the water in the heating circuit stays at below 42 ºC because, when this temperature is
reached, the board turns off the burner.
"Chimneysweep" request
When the master switch (IG) is moved to "RESET" position for at least 10 seconds, the board ignites the
generator in heating phase and keeps this operating at maximum heating power for 15 minutes.
In this phase, only the limit thermostat function is operative (90 ºC) performed by the C.H. sensor (NM).
The function is only engaged if there are no requests under way for hot water or antifreeze and it is
indicated by means of the fast flashing of red LED LD2.
It can be interrupted by cutting power to the circuit or making a hot water request.
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STES ed 07/01 EOLO STAR