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Special functions
Caution
If sensor S4 is not connected, the additional heating source (connected to relay R5) is switched off if the heat-
ing circuit sensor S2 (resp. the heating circuits S2 and S3) reach or exceed the reference
fl
ow temperature.
Caution
To prevent the additional heating source from switching on unnecessarily, it is recommended to install sen-
sor S4 on the same level or lower than the heating circuit outputs in the buffer.
Caution
The heat request is started if the
fl
ow temperature (resp. one of the
fl
ow temperatures when two
heating circuits are active) is below the reference temperature for 5 minutes.
This value is the upper limit of the reference
fl
ow temperature of the heating circuit. If the temperature ex-
ceeds this value, the heating circuit is switched off until the temperature drops below again.
Settings range: 30 °C to 105 °C / Default: 45 °C
7.3.16.10. - Maximum Flow
7.3.16.11. - Reference/actual -
Switch on hysteresis for additional heating
This setting determines the allowed undershoot of the heating circuit temperature below the calculated refer-
ence
fl
ow temperature. If the temperature at the storage sensor HC drops below the reference
fl
ow tempera-
ture by this value, the additional heating will start the additional heat source after a delay of 5 minutes.
Settings range: 1°C to 10°C / Default: 2°C
7.3.16.12. - Reference/
Switch off hysteresis
This setting determines the allowed overstepping of the heating circuit temperature to the calculated reference
fl
ow temperature. If the temperature exceeds the reference
fl
ow temperature by this value, the additional heat-
ing is switched off.
Settings range: -10°C to 10°C / Default: -2°C
Reference sensor for the outdoor temperature
Settings range: S1-S8, VFS1-2, active storage
Reference sensor for the
fl
ow temperature of the 2nd heating circuit
Settings range: S1-S8, VFS1-2, active storage
7.3.16.13. - Outdoor sensor
7.3.16.14. - Flow sensor
The minimum
fl
ow temperature is the lower limit of the heating curve, and by this, the reference
fl
ow tempera-
ture of the heating circuit. Furthermore, this valule is the reference
fl
ow temperature for the frost protection
(see also „6.2. - Frost protection“ on page 28).
Settings range : 5°C to 30°C / Default : 15°C
7.3.16.9. - Minimum Flow
