121
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 to the slope
/
level of the heating
curve.
The determined set boiler water temperature is trans-
ferred to the burner control unit. From the set and
actual boiler water temperatures, the burner control
unit calculates the modulation level and regulates the
burner accordingly.
The electronic temperature limiter inside the burner
control unit limits the boiler water temperature.
Heating the DHW loading cylinder from cold
The heating circuit pump is switched ON and the 3-
way diverter valve will be changed over, if the cylinder
temperature sensor captures a temperature lower than
the defaulted set value.
■
The cylinder loading pump is switched ON if the
boiler water temperature
≥
set cylinder temperature.
■
The burner is switched ON if the boiler water temper-
ature
≤
set cylinder temperature, and the cylinder
loading pump is switched ON when the required
boiler water temperature is reached.
The loading cylinder is heated up to the set cylinder
temperature. Heating stops when the specified temper-
ature has been reached at the cylinder temperature
sensor.
After loading has stopped, the cylinder loading pump
and the 3-way diverter valve remain on for a further
30 s.
Reheating when DHW is drawn off
When DHW is drawn off, cold water enters the lower
section of the loading cylinder.
The heating circuit pump is switched ON and the 3-
way diverter valve is changed over, if the cylinder tem-
perature sensor captures a temperature lower than the
defaulted set value.
■
The cylinder loading pump is switched ON if the
boiler water temperature
≥
set cylinder temperature.
■
The burner is switched ON if the boiler water temper-
ature
≤
set cylinder temperature, and the cylinder
loading pump is switched ON when the required
boiler water temperature is reached.
DHW is regulated to the set temperature via the outlet
temperature sensor.
After the draw off process has ended the loading cylin-
der continues to be heated up, until the set DHW tem-
perature has been reached at the cylinder temperature
sensor.
The cylinder loading pump and the 3-way diverter
valve remain ON for a further 30 s.
Boosting DHW heating
This function is activated by specifying a second set
DHW temperature via coding address 58 in group
"DHW"
and activating the fourth DHW phase for DHW
heating.
Heating is boosted during the periods selected in this
time phase.
Function description
Weather-compensated control unit
(cont.)
5773 216 GB
Functions
Summary of Contents for B2TA
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Page 107: ...107 Parts lists Hydraulics 5773 216 GB Components ...
Page 118: ...118 0004 0002 0005 0006 0001 0003 Fig 77 Parts lists Miscellaneous 5773 216 GB Components ...
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