System Example 2 - Viessmann VITOSOIC 100 Installation And Service Instructions Manual

System example 2

Vitodens – DHW heating and central heating backup with a multi-
mode heating water buffer cylinder
Main components
■ Viessmann solar collectors
■ Vitocell 340-M or Vitocell 360-M multi-
mode heating water buffer cylinder
with integral DHW heating, with or
without stratification system
■ Vitosolic 100, type SD1
■ Solar-Divicon
■ Wall mounted gas boiler from the year
of manufacture 2008
– Vitodens 200-W, type WB2B
– Vitodens 300-W, type WB3C
Function description
DHW heating with solar energy
Solar circuit pump R1 eE starts and
heating water buffer cylinder qP is
heated up if the temperature differential
between collector temperature sen-
sor S1 and cylinder temperature sen-
sor S2 qQ exceeds the start temperature
differential DT E.
Solar circuit pump R1 eE stops if:
■ The actual temperature falls below the
stop temperature differential DT A
■ The electronic temperature limit of
control unit eZ is exceeded (max.
90°C)
■ The temperature selected at high limit
safety cut-out qW (if installed) is
reached
Entire heating water buffer cylinder qP is
heated by the solar thermal system if the
insolation is adequate.
Preparing for installation
The upper part of heating water buffer
cylinder qP will only be reheated by
boiler 1 if the actual water temperature
falls below the set temperature selected
at boiler control unit 2.
If the solar energy is inadequate to cover
the entire heating demand, the DHW in
the lower part of heating water buffer cyl-
inder qP will be preheated by solar
energy. The DHW in the upper part of the
cylinder is heated to the required tem-
perature by boiler 1.
The burner starts and three-way diverter
valve rZ switches to position "AB-A" via
cylinder temperature sensor qZ of the
boiler control unit. When the set DHW
temperature has been reached, the
burner stops and three-way diverter
valve rZ switches to position "AB-B".
Suppression of DHW cylinder reheat-
ing by the boiler
Coding address "67" in boiler control
unit 2 defaults a third set DHW tem-
perature (setting range 10 to 95 °C). This
value must be below the first set DHW
temperature. Heating water buffer cylin-
der qP is only heated by boiler 1 (solar
circuit pump R1 eE runs) if this set value
cannot be achieved by the solar thermal
system.
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