Vaillant VR 71 - Page 17

0020288151_04 Operating and installation instructions 17
Target return temperature: °C Select a temperature at which the heating water should flow back
into the floor-standing boiler.
Factory setting: 30 °C
OT switch-off threshold: °C Enter the upper limit for the outdoor temperature. If the outdoor
temperature rises above the set value, the system control deactiv-
ates heating mode.
Factory setting:
– 21 °C for a conventional heat generator
– 16 °C for a heat pump
Target flow temp., desired: °C Select the temperature for the fixed value circuit which applies
within the time period.
Factory setting: 65 °C
Target flow temp., set-back: °C Select the temperature for the fixed value circuit which applies
outside of the time period.
Factory setting: 0 °C
Heat curve: The heat curve is the dependence of the flow temperature on the
outdoor temperature for the desired temperature (target room tem-
perature). Detailed description of the heat curve (→ Section 2.12)
Factory setting:
– 1.20 for a conventional heat generator
– 0.60 for a heat pump and/or mixed circuit
Min. target flow temperature:°C Enter the lower limit for the target flow temperature. The system
control compares the set value with the calculated target flow tem-
perature, and regulates to the larger of these values.
Factory setting: 15 °C
Max. target flow temperature:°C Enter the upper limit for the target flow temperature. The system
control compares the set value with the calculated target flow tem-
perature, and regulates to the smaller of these values.
Factory setting:
– 90 °C for a conventional heat generator
– 55 °C for a heat pump and/or mixed circuit
Set-back mode: The behaviour can be adjusted separately for each heating circuit.
Factory setting: Eco
Eco The heating function is switched off and the frost protection func-
tion is activated.
At outdoor temperatures that are below 4 °C for longer than four
hours, the system control switches the heat generator on and reg-
ulates to the Set-back temperature: °C. At an outdoor temperat-
ure above 4 °C, the system control switches the heat generator off.
The monitoring of the outdoor temperature remains active.
Heating circuit behaviour outside of the time periods.
Prerequisite:
– Time-contr. is activated in the Heating | Mode: function.
– Active or Inactive is activated in the Room temp. mod.: func-
tion.
If Expanded is activated in the Room temp. mod.:, the system
control regulates to the target room temperature 5 °C independ-
ently of the outdoor temperature.
Normal The heating function is switched on. The system control regulates
to the Set-back temperature: °C.
Prerequisite: Time-contr. is activated in the Heating → Mode:
function.