Viessmann VITODENS 200-W B2HE 85 Operating Instructions Manual page 46

Appendix
Terminology
(continued)
Heating circuit
A heating circuit is a sealed unvented circuit connecting
the boiler and the radiators, in which the heating water
circulates.
A system may comprise several heating circuits.
For example, one heating circuit for the rooms occupied
by you and one heating circuit for the rooms of a separate
apartment.
The heating circuits are designated at the factory as
"Heating circuit 1", "Heating circuit 2", etc.
If you or your qualified contractor have renamed the
heating circuits, e.g. as "Apartment", that name will be
displayed instead of "Heating circuit ...".
Heating circuit pump
Circulation pump for circulating the heating water in the
heating circuit
Mixing valve
Hot heating water from the boiler is mixed with cooled
heating water from the heating circuit. The heating water,
brought to the right temperature as required, is pumped to
the heating circuit by the heating circuit pump.
To ensure the required target room temperature is achieved,
the control unit adjusts the supply temperature via the
mixing valve to suit different conditions.
Night setback
See "Reduced heating operation"
Room air dependent operation
The combustion air is drawn from the room where the
boiler is installed.
Direct vent operation
Combustion air is drawn from outside the building.
Room temperature
Standard room temperature or comfort room
temperature:
Set the standard room temperature or comfort room
temperature for periods when you are at home during
the day.
Reduced room temperature:
For periods when you will be absent or during the night,
set the reduced room temperature; see "Heating
operation".
46
Return temperature
The return temperature is the temperature at which the
heating water leaves a system component such as a
heating circuit.
Safety valve
Safety equipment that must be installed in the cold water
pipe by your contractor. The safety valve opens
automatically to prevent excess pressure in the DHW tank.
The heating circuits are also equipped with safety valves.
Solar circuit pump
In conjunction with solar thermal systems. The solar
circuit pump delivers the cooled heat transfer medium
from the DHW cylinder indirect coil to the solar collectors.
Temperature target
See "Target temperature".
Summer mode
In warmer months, you can switch off heating operation.
To do so, select "DHW" operating program "On" and
"Standby mode".
The system remains in operation for DHW heating.
Central heating is switched off.
Storage tank loading pump
Circulation pump for heating the DHW in the DHW tank.
Target temperature
Specified temperature that should be reached,
e.g. target DHW temperature.
Drinking water filter
A device that removes solids from potable water.
The drinking water filter is installed in the cold water
pipe upstream of the DHW cylinder or the instantaneous
water heater.
Supply temperature
The supply temperature is the temperature at which the
heating water enters a system component such as a
heating circuit.
Weather-compensated operation
See "Heating operation"
Time program
In the time programs you determine what your heating
system should do at what time.
Operating status
The operating status indicates how a component of
your heating system is being operated.
For example, the operating statuses for central heating
have different temperature levels.
The times for the operating status changeover are defined
when the time program is set.
DHW recirculation pump
The DHW recirculation pump transports the DHW around
a loop line between the DHW tank and the draw-off
points (e.g. hot tap). This ensures that hot water is rapidly
available at the draw-off points.
Vitodens 200-W B2HE Operating