Viessmann VITOLIGNO 300-P Service Instructions Manual page 34

Commissioning, inspection, maintenance
Further details regarding the individual steps
Central heating by the Vitoligno 300-
P and solar thermal system
The multi mode heating water buffer cyl-
inder Vitocell 340-M or 360-M is heated
by the solar thermal system. The boiler
remains shut down if the solar thermal
system can provide sufficient heat.
DHW heating without solar energy
The top part of the cylinder is heated by
the boiler. The integral instantaneous
water heater/standby part is heated by
the surrounding buffer cylinder water.
On demand, the cylinder temperature
controller with cylinder temperature sen-
sor qQ switches 3-way diverter valve
qO over towards the cylinder/standby
part.
34
(cont.)
DHW heating with solar energy
If a temperature differential between the
collector temperature sensor wQ and cyl-
inder temperature sensor qT is captured
that is higher than the temperature dif-
ferential set on the control unit, solar cir-
cuit pump wE starts and cylinder qR will
be heated. For this, the temperature
inside the cylinder will be limited by elec-
tronic temperature limiter wZ in the
Vitosolic 100. This stops solar circuit
pump wE when the set temperature is
exceeded. The electronic temperature
limiter is preset at the factory to 60 °C
and can be adjusted.
The entire cylinder is heated by the solar
thermal system if the solar radiation is
adequate for DHW heating. The top part
of the cylinder will only be reheated by
the boiler if the temperature of the water
falls below the temperature set at
Vitotronic 200 2.
The DHW in the lower area of the cylin-
der will be preheated by solar energy
and the top area heated to the required
temperature by the boiler if the solar radi-
ation level is inadequate.