8 Heating circuit
activates the frost protection mode for the hea-
ting circuit for the duration of the holiday.
activates the reduced mode for the heating cir-
cuit for the duration of the holiday.
This icon indicates an activated holiday mode in
the
heating circuit
screen.
8.1.2 General settings
Cutoff temperature
If the outdoor temperature exceeds the value set here,
the heating circuit pump is switched off and the hea-
ting circuit mixer closes.
Cutoff temperature for heating mode: 18°C
Cutoff temperature for reduced mode: 5°C
i
This means: the heating circuit is normally auto-
matically switched off during the summer
month due to the outdoor temperature.
You can also switch the heating circuit off
manually (=operating mode: Switch off heating
circuit).
Anti-freeze temperature
If the outdoor temperature drops below the value set
here, the heating circuit pump is switched on.
Buffer difference
The burner starts when the tank temperature top falls
below the required flow temperature minus the buffer
difference.
Example:
- Current flow required temperature = 50°C
- Buffer difference = 5°C
starts as soon as
tank temperature top
< 45°C.
A negative buffer difference value is added, i.e. the bur-
ner starts earlier.
Example:
- Current flow required temperature = 50°C
- Buffer difference = - 5°C
The burner starts as soon as tank temperature top <
55°C.
Ext. temperature delay
The delay set here is used to determined an average
value for the outdoor temperature (= Average outdoor
temperature).
The heating circuit pump switches on if the Average
temperature and the Current outdoor temperature fall
below the cutoff temperature (within the heating
period), or below the reduced mode cutoff temperature
(outside the heating period).
The heating circuit pump switches off again as soon
as the current outdoor temperature rises above the
value of the cutoff temperature.
Heating circuit name
Individual naming of the heating circuit is possible.
8.1.3 Heating curve
The heating circuit flow temperature is controlled by
the heating circuit operating mode
and by the
outdoor temperature. The heating curve represents the
relationship between these two temperatures. I.e. the
control unit uses the outdoor temperature to calculate
the temperature (=calculated nominal flow tem-
perature) with which the heating circuit is supplied.
In
heating mode
the heating curve for heating mode
4
(red) is used.
In
reduced mode
the heating curve for reduced mode
5
(= heating curve for heating mode minus
reduction
) is
used.
The heating curve must be adapted to suit each buil-
ding and its heating system.
Operation manual
therminator II touch
23
