90
48 °C
Boiler temperature
HC1
14°C
21°C
Fig. 66
Heating mode
The control unit determines a set boiler water tempera-
ture subject to outside temperature or room tempera-
ture (if a room temperature-dependent remote control
is connected) and the slope/level of the heating curve.
The set boiler water temperature determined is then
transferred to the burner control unit.
The burner control unit calculates the current heat
demand and actuates the 2-stage burner accordingly.
The burner is started up in burner stage 1. If the heat-
ing output of burner stage 1 is not sufficient for the cur-
rent heat demand, burner stage 2 is also switched on.
The boiler water temperature is limited in the burner
control unit: To 74 °C by the temperature controller and
to 82 °C by the electronic temperature limiter. If the
boiler water temperature reaches 100 °C, the tempera-
ture limiter in the safety chain locks out the burner con-
trol unit.
DHW heating
The burner and the circulation pump for cylinder heat-
ing are started if the cylinder temperature is 2.5 K
below the set cylinder temperature.
In the delivered condition, the set boiler water temper-
ature is 20 K higher than the set cylinder temperature
(adjustable via coding address "60"). If the actual cylin-
der temperature exceeds the set cylinder temperature
by 2.5 K, the burner shuts down and circulation pump
run-on begins.
Boosting DHW heating
This function is activated by specifying a second set
DHW temperature via parameter/coding address 58 in
the
"DHW"
group and activating the fourth DHW time
phase for DHW heating.
Heating is boosted during the periods selected in this
time phase.
Function description
Control unit
6136330
Service
