Viessmann VITOCAL 222-G Operating Instructions Manual page 55

Terminology
(cont.)
Room temperature-dependent heat-
ing or cooling mode
With room temperature-dependent oper-
ation a room will be heated or cooled
until the selected set room temperature
has been reached. For this, a separate
temperature sensor must be installed in
a room.
The heating output or cooling capacity
are regulated independent of the outside
temperature.
Reduced heating mode
When you are out or during the night, you
can heat the rooms in reduced heating
mode (setback mode). Set the time peri-
ods using the time program for central
heating. During these times, the rooms
are heated to a reduced room tempera-
ture.
In reduced mode, cooling is disabled.
Reduced room temperature
When you are out or during the night, set
a reduced room temperature (see
page 19). See also "Reduced heating
mode".
Safety valve
Safety device that must be installed by
your heating contractor in the cold water
pipe. The safety valve opens automati-
cally to prevent excess pressure in the
DHW cylinder.
The heating circuits and the solar circuit
are also equipped with safety valves.
Secondary pump
The secondary pump transports the
heating water from the heat pump into
the heating system and, in heating sys-
tems with heating water buffer cylinder,
initially into the buffer cylinder.
Solar circuit pump
In conjunction with solar thermal sys-
tems.
The solar circuit pump transports the
cooled heat transfer medium from the
DHW cylinder indirect coil to the collec-
tors.
Set temperature
Default temperature that should be
reached by heating or cooling; e.g. set
DHW temperature.
Cylinder primary pump
Circulation pump for heating the DHW in
the DHW cylinder.
Potable water filter
Device that removes solids from the
water. The potable water filter is installed
in the cold water pipe upstream of the
DHW cylinder or the instantaneous
water heater.
Compressor
Central assembly of a heat pump. The
compressor raises the refrigerant to the
temperature level required for the heat-
ing operation.
Appendix
55