Viessmann Vitolig
200 Technical Manual page 27

Application example 3
to support space heating and one or two heating circuits with mixer
For heating systems with heat demand:
< 18 kW for Vitolig 300, 5 to 15 kW
<12 kW for Vitolig 300, 8 to 26 kW
The heating circuits with mixer and the
DHW cylinder, are controlled by the
heating circuit controller of Vitolig 300.
Vitolig 300 will only be started if there is a
demand from the DHW cylinder or from
the heating circuit. The timer program for
heating operation and heating up the
DHW cylinder is set at the remote control
unit of the heating circuit controller. The
heating circuit pump is switched via the
heating circuit pump logic, providing
there is a heat demand.
Upon demand, the boiler is operated with
the required boiler water set temperature
or the minimum temperature of 60 ºC. A
DHW demand which is given priority
causes the heating circuit pump to be
switched off and the mixer to be closed.
When the DHW cylinder reaches its set
temperature, the system changes over to
the heating circuit.
The boiler and the boiler circuit pump are
switched on if there is a boiler demand.
The boiler circuit pump runs on for
10 min. after Vitocell 333 has been heated
up.
The mixing valve in the return
temperature raising facility holds the
boiler water return temperature at a
minimum of 45 ºC.
Set the water circulation volume inside
the boiler circuit of Vitolig 300, so that a
temperature spread of 15 K between the
boiler flow and return results at the rated
boiler output.
The boiler is switched off, if neither DHW
cylinder nor heating circuit make any
more demands.
The pellet feed control unit enables the
filling of the pellet container for each day.
Space heating with Vitolig 300 and solar
energy
Vitocell 333 is heated up by the solar
heating system. Vitolig 300 remains idle,
if the solar heating system can provide
sufficient heat.
If the temperature of the pre−heated
cylinder water is insufficient, the boiler
re−heats the water to the necessary flow
temperature level, as described above.
Vitolig 300 plus Vitocell 333 for dual DHW heating and
Domestic hot water heating without
solar energy
The top part of the Vitocell 333 is heated
by the boiler. The integrated
instantaneous water heater/standby
reservoir is heated by the surrounding
hot water of the buffer storage unit.
The cylinder thermostat with the
connected cylinder temperature
sensor qE changes the 3 way changeover
valve 5 on demand to AB A.
Domestic hot water heating with solar
energy
When a temperature difference higher
than the differential temperature set in
Solartrol M wP is measured between the
collector temperature sensor wQ and the
cylinder temperature sensor wW, the
circulation pump of the solar circuit wR is
switched on and Vitocell 333 is heated up.
The temperature inside Vitocell 333 will
be limited by the electronic temperature
limiter in Solartrol M wP.
If the preset temperature is exceeded, this
device switches off the circulation pump
of the solar circuit wR.
The electronic temperature limiter is
factory−set to 75 ºC and can be adjusted.
The entire Vitocell 333 will be heated by
the solar heating system if the solar
irradiation is sufficient for heating the
domestic hot water.
The top part of Vitocell 333 will only be
re−heated by the boiler if the temperature
of the water falls below the temperature
set at the remote control unit.
If the solar irradiation is insufficient, the
bottom part of Vitocell 333 will be
pre−heated by solar energy whilst the top
part is raised to the required temperature
by the boiler.
3 Vitolig 300
¨ Safety instructions
With temperatures higher than 60 ºC, the
domestic hot water temperature must be
limited to 60 ºC by installing a mixing
device, e. g. a thermostatic mixing valve
(DHW cylinder accessory). The mixing
device does not prevent the risk of
scalding at the tap.
The installation of a mixer tap is required.
Please note
To avoid re−circulation, it is advisable to
install a heat insulating loop or an
additional check valve into the flow of the
solar heating circuit.
DHW cylinder details
Operate the system with DHW cylinder
heating as priority. See installation
instructions heating circuit controller.
27