ST-408N – user's manual
The protection against too high return temperature serves to prevent the
hazardous growth in CH boiler temperature. The user sets the maximum
acceptable return temperature. In the case of the hazardous growth in
temperature, the valve begins to open to house installation in order to cool the CH
boiler down. This function is activated permanently (it may be deactivated only in
service menu).
IV.d.15)Return protection
This function permits setting the boiler protection against too cool water
returning from the main circulation, which could cause low-temperature boiler
corrosion. The return protection involves closing the valve when the temperature
is too low, until the short circulation of the boiler reaches the appropriate
temperature. After activating it, the user presets the minimum acceptable return
temperature.
IV.d.16) Pump activation:
This option enables the user to select the working mode of a pump. A
pump will be activated: always (the pump operates all the time, regardless of
temperatures), never (the pump is permanently deactivated and the regulator
controls only valve operation), above the threshold (the pump is activated above
the set activation temperature). If the pump is to be activated above the
threshold, the user should also define the threshold temperature of pump activation.
When the CH pump room regulator function is activated, the CH pump is switched
off after reaching the set temperature (if always or above the threshold option is
selected).
IV.d.17) IV.d.17) Weekly control (weekly program)
This function is used for programming daily changes of the temperature
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