The measured temperature reading (return flow temperature) and the set point reading (flow temperature of the heating, charging temperature) blink to indicate that a return flow limitation is active in the control circuit concerned. In systems Anl 2, 3, 7, 8 and 9, the Return flow limita- tion temperature parameter during DHW heating is used for limitation in the primary circuit while the DHW heating is active. The systems Anl 4, 5, 6 and 11 allow a separate return flow sensor to be installed in the DHW circuit.
To ensure that the preset Return flow temperature limit temperature during DHW heating can be met, make sure that:
–the heating characteristic is not adjusted to ascend too steeply,
–the speed of the circulation pumps is not set too high,
–the heating systems have been calibrated.
Note!
For outdoor temperature dependent control with gradient characteristic, the return flow tempe- rature is limited to fixed set point by entering the same value for both Maximum return flow tem- perature and Minimum return flow temperature parameters.
Functions | WE | Configuration | ||
Return flow sensor RüF1 | ON | FB20 = ON | ||
| 1 |
| Limiting factor / 0.1 to 10 | |
Return flow sensor RüF2 | OFF | FB21 = ON | ||
| 1 |
| Limiting factor / 0.1 to 10 | |
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Parameters | WE | Range of values | ||
Gradient, return flow | 1.2 |
| 0.2 to 3.2 | |
Level, return flow | 0 | °C | °C | |
Maximum return flow temperature | 65 | °C | 20 to 90 | °C |
Minimum return flow temperature | 65 | °C | 20 to 90 | °C |
Return flow temperature limit temperature during | 65 | °C | 20 to 90 | °C |
DHW heating |
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Note!
In systems Anl 2, 5, 7 and 9 The function block setting FB20 = ON or FB21 = ON provides two switching conditions for the storage tank charging pump (SLP) that can be selected when the heating circuits are switched off:
(1)SLP switched on regardless of the return flow temperature
(2)SLP switched on depending on the return flow temperature
58EB 5476 EN
