EB 5573 EN
75
Functions of the DHW circuit
7
Functions of the DHW circuit
7.1
DHW heating in the storage tank system
Start storage tank charging
KW
WW
SF1
ZP
SLP
SLP
Storage tank charging pump
SF1
Storage tank sensor 1
ZP
Circulation pump (DHW)
WW
Hot water
KW
Cold water
Fig. 8:
Schematics of a storage tank system
The controller begins charging the storage tank when the water temperature measured at
sensor SF1 falls below the 'DHW temperature set point' by 0.1 °C. If the flow temperature in
the system exceeds the desired charging temperature, the controller tries to reduce the flow
temperature in the heating circuit for up to three minutes before the storage tank charging
pump is activated. When there is no heating operation or when the flow temperature in the
system is lower, the storage tank charging pump is switched on immediately.
If the function CO4 > F15 - 1 (
SLP ON depending on return flow temperature
) is activated,
the primary valve is opened without simultaneously operating the storage tank charging
pump. The storage tank charging pump is first switched on when the primary return flow
temperature has reached the temperature currently measured at storage tank sensor SF1.
This function enables storage tank charging when the heating system is switched off, e.g. in
summer mode, without cooling down the storage tank first by filling it with cold flow water.
The storage tank charging pump does not start operation before a sufficiently high tempera-
ture has been reached at the heat exchanger.
When a storage tank thermostat is used, the 'Charging temperature' parameter can be ad
-
justed at the rotary switch as the absolute value instead of the 'DHW temperature' parame
-
ter.
Note