4.9 Limitation of the system deviation for OPEN signal
When using the controller for steam pressure control, we recommend that you activate this func-
tion. It limits the controllers reaction to set point deviations which cause the control valve to
open. This makes it much easier to start up such systems without complications. The controllers
response to set point deviations which cause the control valve to close are not affected by this
function.
In the system code numbers 1, 2 and 3, the function must be activated via FB 11 = ON.
In the system code numbers 4, 5 and 6 set
FB 11 = ON to activate the function linked to the heating circuit, and
FB 12 = ON to activate the function linked to the drinking water circuit.
4.10 Forced charging of drinking water storage tank
Systems 2, 3 and 5 are equipped with this function as standard, provided that a storage tank
sensor (not a storage tank thermostat) is used.
To guarantee sufficient charging of the drinking water storage tank at the time when the rated
operation of the heating circuit begins (or when the preheating period in the optimize mode
begins), forced charging commences one hour before the time-of-use set of the heating circuit
begins (or one hour before the preheating period in the optimize mode), provided that the time-
of-use of the drinking water circuit does not end as the time-of-use the heating circuit starts.
The drinking water heating finishes as usual when the temperature Drinking water heating
OFF is reached.
4.11 Thermal disinfection of the drinking water storage tank
This function cannot be used in conjunction with a storage tank thermostat.
The thermal disinfection is first activated by the function block setting FB 7 = ON. You can select
whether the thermal disinfection should run on a certain day of the week or daily.
Drinking water heating is started on the days concerned at the start time set to heat up the water
to disinfect it. The thermal disinfection finishes at the stop time set at the latest.
(Settings in the configuration level, linked to function block setting FB 7 = ON. Default: week
day 3 Wednesday; start time 0:00 hrs, stop time 4:00 hrs, these times can be changed in 30
min. steps; deactivating temperature 70 °C, setting range 60 to 90 °C).
Systems 2, 3 and 5 function with a 5 °C higher deactivating temperature for charging the stor-
age tank. In System 4, the drinking water set point corresponds to the deactivating temperature
+5 °C; however, thermal disinfection also finishes when the deactivating temperature in the stor-
age tank is reached.
If the required temperature in the storage tank is not reached before the stop time, the thermal
disinfection procedure is interrupted. However, the return flow temperature in the drinking
water circuit is not limited by it.
A parallel pump operation selected using the parameter FB 9 = ON is not carried out during
thermal disinfection. The procedure of thermal disinfection is also not interrupted by an inter-
mediate heating operation (systems 2 and 3). The circulation pump remains in operation con-
trary to the default drinking water heating in systems 2 and 4 during the thermal disinfection !
4.12 Frost protection
Generally, the heating circuit circulation pump UP is activated when the outdoor temperature
falls below +3 °C. A flow temperature set point of 10 °C is used for control.
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