Viessmann Vitolig
200 Technical Manual page 39

Application example 2
boiler, DHW cylinder, heating water buffer storage unit and one or two heating circuit(s) with mixer
Priority cylinder heating in parallel operation Vitolig/heating water buffer storage unit
Notes
The water connection designs on the
following pages also apply to Vitolig 100.
Alternative functions and wiring
diagrams are described from page 61
onwards.
The temperatures stated in the
application example are standard values;
set alternative values according to the
relevant requirements.
The heating circuits and one DHW
cylinder are heated by Vitolig, by one
heating water buffer storage unit and one
oil− or gas−fired boiler. The operation is
automatically changed over between
Vitolig and the oil− or gas−fired boiler.
Both are either connected to different
chimneys or to a common chimney acc.
to DIN 4759−1.
Combustion controller and control of the
Vitolig circulation pump
After Vitolig has been heated up, it is
operated at full load. The boiler circuit
pump 3 is switched on, when Vitolig
reaches a water temperature of 60 ºC.
Either the heating circuit or the DHW
cylinder are heated up. The heat not
drawn off by consumers is transferred to
the heating water buffer storage unit.
The layer load operation begins, if 70 ºC
is exceeded for longer than 30 min. at
sensor qR at the top of the heating water
buffer storage unit.
Vitolig is operated at 50% output, and the
heating water buffer storage unit is
heated up to 80 ºC boiler water
temperature.
The layer load operation ceases, if the
temperature at the top of the heating
water buffer storage unit at sensor qR
falls below 70 ºC. The boiler output is
enabled and the boiler water temperature
regulated to 70 ºC.
The Vitolig boiler circuit pump 3 is
switched off by the differential
temperature control if the heating water
buffer storage unit is heated up and the
boiler water temperature is below that at
the bottom of the buffer (T
PU
sensor qT.
Return temperature raising facility
Vitolig requires a minimum return
temperature of 45 ºC. When the boiler
circuit pump 3 is switched on, the
mixing valve 4 opens the path from the
heating return to Vitolig in line with the
rising return temperature, and
simultaneously closes the path from the
flow to the return (bypass).
Vitolig 200 (or Vitolig 100) with oil /gas fired boiler or wall−mounted gas−fired
Domestic hot water heating
H DHW heating through the oil− or
gas−fired boiler
The Vitolig boiler water temperature is
below 60 ºC, the temperature in the
heating water buffer storage unit is lower
than the value set at thermostat qE (DHW
temperature + 10K).
The burner of the oil− or gas−fired boiler
starts and the DHW circulation pump 5
activates, if the DHW cylinder
temperature falls below the value set at
the cylinder thermostat of the boiler
circuit control unit. The three−way mixer
8 in the heating circuit is closed and the
heating circuit pump 7 is switched off.
The three−way changeover valve qP from
the oil− or as−fired boiler to the distributor
is open.
H DHW heating through Vitolig
The Vitolig boiler water temperature is at
least 60 ºC; the boiler circuit pump 3
runs to raise the return temperature. The
three−way changeover valve qP will open
towards Vitolig and from the heating
water buffer storage unit towards the
distributor, the circulation pump 5 is
activated (if the temperature set at
thermostat qE is exceeded), and the DHW
cylinder is heated up, if the DHW cylinder
temperature falls below the value set at
the boiler circuit control unit.
When connecting the boiler to a common
chimney, the thermostats qE and qZ
prevent the DHW circulation 5 being
switched on and the DHW cylinder
cooling down, for as long as the burner is
still locked out by the flue gas
temperature monitor qI. Consequently
the oil− or gas−fired boiler remains cold.
After Vitolig is started, initially the DHW is
heated up; space heating is only provided
afterwards.
The three−way mixer 8 of the heating
circuit is closed when DHW is heated. The
circulation pump 5 is switched off, the
three−way mixer 8 is opened and heat is
transferred to space heating, when the
DHW temperature set at the cylinder
thermostat of the boiler circuit control
unit has been reached.
+ 5K) at
4 Vitolig 200
H DHW cylinder heating through the
heating water buffer storage unit
The Vitolig boiler water temperature is
below 60 ºC, the heating water
temperature in the heating water buffer
storage unit is higher than 65 ºC or at
least 10 K higher than the DHW
temperature set at the DHW cylinder
thermostat. The three−way changeover
valve qP is open from Vitolig and from
the heating water buffer storage unit
towards the distributor. The DHW
circulation pump 5 activates, and the
DHW cylinder is heated up.
DHW heating ends, when the actual
temperature falls below the temperature
set at the cylinder thermostat of the boiler
circuit control unit. The circulation
pump 5 and the three−way changeover
valve qP remain open from Vitolig and
from the heating water buffer storage unit
towards the distributor.
The circulation pump 5 will also
deactivate, if the actual heating water
buffer storage unit temperature falls
below that set at thermostat qE. The
DHW cylinder is heated up through the
oil− or gas−fired boiler.
Heating mode
H Heating through the oil− and gas−fired
boiler
The burner of the oil− or gas−fired boiler
will be enabled, if the Vitolig boiler water
temperature lies below 60 ºC, if the
temperature in the heating water buffer
storage unit lies below the value set at
thermostat qW and, when connected to a
common chimney, the flue gas
temperature lies below the value set at
the flue gas temperature controller qI,
i.e. 60 ºC. The three−way changeover
valve qP is open from the oil− or gas−fired
boiler to the distributor.
The boiler circuit control unit of the oil− or
gas−fired boiler automatically adjusts the
boiler water temperature to the respective
outside temperature. The heating flow
temperature is controlled via the
three−way mixer 8 subject to the outside
temperature.
H Heating through Vitolig
The three−way changeover valve qP
opens from Vitolig and from the heating
water buffer storage unit towards the
distributor, if the Vitolig boiler water
temperature exceeds 60 ºC and the DHW
cylinder is heated up. The heat created by
Vitolig is transferred via boiler circuit
pump 3 to the heating circuit and to the
heating water buffer storage unit. The
heat not drawn by the heating circuit is
transferred to the heating water buffer
storage unit.
The heating circuit flow temperature is
controlled by the Vitolig boiler circuit
control unit via the three−way mixer 8.
39