139
Functions
■
Time program
The automatic program or an individual time program
can be selected for DHW heating and the DHW cir-
culation pump.
In the individual time program, up to 4 time phases
per day can be set via the time switch for DHW heat-
ing, and 4 time phases for the DHW circulation
pump.
■
Priority control
The priority control of cylinder heating can be adjus-
ted individually for each heating circuit.
–
With priority control: (code 2 "A2:1", heating
group):
The set flow temperature will be adjusted to 0 °C
during cylinder heating.
The mixer closes and the heating circuit pump is
running.
Only possible when the heating circuit is wired on
the internal boiler PCB. When using an extension
kit for the heating circuit, the heating circuit pump
is switched off.
–
With priority control: (code 2 "A2:2", heating
group):
The set flow temperature will be adjusted to 0 °C
during cylinder heating.
The mixer closes. The heating circuit pump is
switched off.
–
With reduced priority control: (code 2 "A2:3", heat-
ing group)
The heating circuit pump remains switched on.
During cylinder heating, the set flow temperature of
the heating circuit will be reduced to the set value
of reduced heating mode until the set flow temper-
ature has been reached.
The set flow temperature is determined from the
following parameters:
–
Outside temperature
–
Differential between the set and the actual boiler
water temperature
–
Heating curve slope and level
–
Without priority control: (code "A2:0", heating
group)
The heating circuit control unit continues to oper-
ate with the same set value.
■
Set DHW temperature
The set DHW temperature can be adjusted between
10 °C and 70 °C.
■
DHW circulation pump
The DHW circulation pump delivers hot water to the
draw-off points at adjustable times.
Up to 4 time phases can be set at the time switch.
■
Reheating suppression
A second set DHW temperature can be specified via
coding address "67".
Reheating by the boiler will be suppressed above
this value. The DHW cylinder is heated exclusively
by the solar thermal system.
Control sequence
The circulation pump for cylinder heating starts when
the differential between the buffer cylinder temperature
(top sensor) and the actual cylinder temperature
exceeds the setting (coding address "0C").
The circulation pump for cylinder heating stops when
the boiler water/buffer cylinder temperature (top sen-
sor) falls below the actual cylinder temperature by the
differential of the values of coding address "0C".
■
DHW cylinder goes cold (set value 10 K):
Pump on
Circulation pump for cylinder heating is started sub-
ject to boiler water temperature (code "61:0"):
The circulation pump starts when the boiler water
temperature is higher than the DHW temperature.
■
DHW cylinder is hot:
Pump run-on
After cylinder heating, the circulation pump runs on
until one of the following criteria is met when the
boiler is operating:
–
The differential between boiler water and DHW
temperature is too small (code 0C, DHW group).
–
The set DHW temperature is exceeded.
Vacuum supply system
A vacuum system transports the pellets from the con-
nector of the room discharge or pellet silo into the pel-
let hopper on the boiler.
Function description
Control functions
(cont.)
5679249
Functions
