EB 5573 EN
79
Functions of the DHW circuit
steps of 1 °C. When the set point in the heat exchanger charging circuit reaches the 'Max.
charging temperature', the set point is no longer increased. An “Err 4“ error message is gen-
erated.
The set point in the heat exchanger circuit which is valid at the end of the charging cycle will
be used again at the beginning of the next cycle.
If times-of-use have been programmed for DHW heating, the 'DHW temperature set point'
adjusted at the rotary switch is applied during these times-of-use. Outside the times-of-use,
the 'DHW temperature sustaining value' parameter is used as the basis. This function does
not apply when a storage tank thermostat is used.
Time-controlled switchover of storage tank sensors
By configuring a second storage tank sensor SF2, it is possible to determine by setting the
function block CO4 > F19 -1 that the storage tank sensor SF1 is used for day mode in the
DHW circuit and storage tank sensor SF2 for night mode. As a result, different storage tank
volumes can be kept at a constant temperature according to a time schedule and also at dif-
ferent temperatures if the 'DHW temperature set point' and 'DHW temperature sustaining
value' differ from one another.
Stop storage tank charging
The controller stops charging the storage tank when the water temperature measured at sen-
sor SF2 has reached the temperature T = 'DHW temperature' + 'Hysteresis'. To do so, the
heat exchanger charging pump is immediately switched off.
When there is no heating operation or when the flow temperature demand in the system is
lower, the corresponding valve is closed. The storage tank charging pump is switched off af-
ter t = 'Lag time of storage tank charging pump' x 'Valve transit time'.
Functions
WE
Configuration
Storage tank sensor SF1
1
CO4 > F01 - 1
Storage tank sensor SF2
1
CO4 > F02 - 1
Flow sensor VF4
0
CO4 > F05
Time-controlled changeover of storage
tank sensors
0
CO4 > F19
Note