The characteristic curve is used to control the heat dissipation of the heating circuit relative to the outdoor temperature. The
demand for heat differs due to factors such as the type of building, heating, insulation and outdoor temperature. For this reason,
the controller can operate with a normal straight curve (setting ‚simple‘) or split curve (setting ‚split‘).
If ‚simple‘ is selected, the curve is adjusted using the graphic diagram. While setting the slope, the controller also shows the slope
value and the calculated target flow temperature at -12 °C as a reference point.
If ‚split‘ is selected, the curve is set in the following steps:
1. Slope over outdoor temperature for change
2. Outdoor temperature for slope change
3. Slope below outdoor temperature for change
While setting the slope, the controller also shows the slope value and the calculated target flow temperature at -12 °C as a ref-
erence point. In case of repeated adjustment of the split curve, the settings appear in reverse order.
The diagram shows the influence of the selected characteristic curve
steepness (standard curve) on the calculated reference flow
temperature of the heating unit. The correct characteristic curve is determ-
ined by defining the intersection point of the maximal calculated flow tem-
perature (=design temperature) at minimal outdoor temperature.
Example: The design temperature of the heater 60 °C flow at lowest out-
door temperature according to calculation of heat requirement
-12 °C. The intersection point renders a slope of 1.2 as the setting.
Day Correction
Parallel characteristic translation
The day correction causes a parallel shift of the heating curve during daytime operating hours, because with certain outdoor tem-
peratures the building might not be optimally heated with the set heating curve. With a non-optimised heating curve, the following
situations frequently occur: hot weather = room too cold/cold weather = room too hot. In this case, the slope of the curve should
be reduced stepwise by 0.2 points and increases the day correction
by 2 ... 4 °C each.
Night Correction
Parallel characteristic translation
The night correction produces a parallel translation of the heating characteristic during the nighttime operating hours. If a neg-
ative value is set for the night correction, the reference flow temperature is lowered accordingly during the nighttime operating
hours. In this manner, primarily at night, but also during the day when no-one is at home, the room temperature is lowered, thus
saving energy. Example: A day correction of +5 °C and a night correction of -2 °C produces a reference flow temperature in night-
time operation that is 7 °C lower.
Comfort Temperature Boost
Parallel characteristic translation
The comfort temperature boost is added to the set day correction. In this manner it is possible to carry out quick heating and/or
raise the temperature of living spaces at a certain time each day.
Min. Flow
The minimum flow temperature is the lower limit of the heating curve, and by this, the reference flow temperature of the heating cir-
cuit. In addition to that, the minimal flow temperature is the reference flow temperature for the frost protection function.
Max. Flow
This value is the upper limit of the reference flow temperature of the heating circuit If however, the temperature of the heating cir-
cuit exceeds the set value, the heat circuit shuts down until the temperature falls below this value. The system purged for 30
seconds every 5 minutes.
The customer must provide an additional limiting thermostat which is connected to the pumps in series (eg underfloor
heating) for safety.
Reference/Actual -
Switch on hysteresis for additional heating
This setting determines the allowed undershoot of the heating circuit temperature below the calculated reference fl ow tem-
perature. If the heating circuit flow temperature and the storage temperature drop below the reference flow temperature by this
value, the additional heating will start the additional heat source after a 1 minute delay.
15
