Drinking water heating process
Charging of the drinking water storage tank is started when the drinking water temperature in
the storage tank falls below the temperature value Drinking water heating ON or the value set
at a storage tank thermostat.
The controller attempts to reduce flow temperatures that are higher than the set Charging tem-
perature over the heating circuit before the heat exchanger charging pump together with the
storage charging pump start to operate.
When the heating circuit is deactivated as well as at lower flow temperature demands, the stor-
age charging pump is activated immediately, while the storage charging pump is first activated
when the flow temperature reaches the temperature at the storage tank sensor SF1.
With the default setting FB 9 = OFF harsh priority, i.e. the heating circuit is deactivated while
the drinking water heating is active long-term charging can be interrupted after 20 minutes
for 10 minute periods by the heating operation. For this, set the function block FB 9 = OFF, and
select the option "20".
With the setting FB 9 = ON and the option "PU" selected parallel pump operation the heat-
ing circulation pump only continues to run when the increase in flow temperature in the heating
circuit is maximum 10 K Max. flow temperature at the maximum.
Should the capacity available for parallel operation be too low, causing the charging tempera-
ture to remain more than 5 K under the set value, the heating operation is interrupted for 10
minutes. The time span before the parallel operation is canceled can be set in FB 9.
The storage tank charging stops when the drinking water temperature in the storage tank rea-
ches the temperature value Drinking water heating OFF or the preset value at the storage tank
thermostat. This occurs when the flow temperature demand of the heating circuit is correspon-
dingly high because the storage charging pump has just been deactivated or in accordance
with the parameter setting End charging process when the flow temperature demand of the
heating circuit is lower. In any case, the storage charging pump is deactivated, at the latest, af-
ter two transit periods of the control valve 2xTy have elapsed; 15 seconds after the heat ex-
changer charging pump has been deactivated, the storage tank pump stops running.
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