Functional description
88
Heating circuit control
(continued)
Functions
(continued)
Summer energy saving function
(heating circuit pump logic)
If the outdoor temperature is higher
than the preset room temperature
set-point value, the heating circuit
pump is switched off and the set-point
supply temperature value is set to
0°C / 32°F.
The switching threshold can be
individually selected via coding address
”A5”.
Extended summer energy saving
function
The heating circuit pump can be
switched off
If the outdoor temperature exceeds a
value preselected via coding address
”A6”
If the set-point room temperature is
reduced via coding address ”A9”
In conjunction with mixing valve
circuit:
If the mixing valve has been closed
for longer than 12 minutes (mixing
valve energy saving function, coding
address ”A7”)
Slab curing function
(only in conjunction with mixing valve
circuit)
Please note:
The slab curing function is selectable
on the basis of four different
temperature curves. The curves are
activated via coding address ”F1”
(see page 134).
When the slab curing function is
activated, the heating circuit pump of
the mixing valve circuit is switched on
and the supply temperature is
controlled according to the selected
curve. When the slab curing time (30
days) has expired, the mixing valve
circuit is automatically controlled on
the basis of the preset parameters.
System dynamics – mixing valve
circuit
(only in conjunction with
mixing valve circuit)
The control behaviour of the mixing
valve can be influenced via coding
address ”C4”.
Frost protection
A supply temperature of 15 to 22°C /
59 to 72°F is assured for outdoor
temperatures below +1°C / 34°F
(two-point control).
For possible changes, see coding
address ”A3” (variable frost threshold).
Therm-Control
Heating circuit output reduction takes
place if the boiler return temperature
falls below the setpoint value (value
read on the therm-control sensor).
Heating circuit mixing valves modulate
closed until the Therm-control sensor
is satified.
Supply temperature control
Differential temperature:
The differential temperature can be
selected via coding address ”9F”,
factory setting: 8°C / 14°F.
The differential temperature is the
minimum difference by which the
boiler water temperature should
exceed the highest currently required
supply temperature of the mixing
valve circuit.
System with only one mixing
valve circuit:
The desired boiler water
temperature is automatically
controlled at 8°C / 14°F above
the desired supply temperature
value.
System with heating circuit and
mixing valve circuit:
The desired boiler water
temperature is controlled according
to its own heating curve. The
temperature difference of
8°C / 14°F.
from the desired supply
temperature is preset in the
factory.
A
Max. boiler water temperature
B
Slope = 1.8 Heating circuit
C
Slope = 1.2 Mixing valve circuit
D
Boiler water temperature
(with differential temperature =
8°C / 14°F.)
E
Minimum boiler water
temperature
5285
941
-
0
1
B
oiler
w
ater
temperature/
supply
temperature
in
°C
Outdoor temperature in °C