Viessmann VITOSOLIC 200 Installation And Service Instructions Manual page 42

System examples
System example 6
Central heating with solar energy
Three-way diverter valve R6 rZ is
switched to position "AB-A" and the heat-
ing return water is routed to boiler 1 via
heating water buffer cylinder rP, if the
temperature differential between buffer
cylinder temperature sensor S5 rW and
heating circuit return temperature sensor
S6 rT exceeds start temperature differ-
ential ΔT6on. If the temperature of the
preheated return water is too low,
boiler 1 reheats the water to the
required flow temperature. Three-way
diverter valve R6 rZ is switched to posi-
tion "AB-B" if the actual temperature falls
below the stop temperature differential
ΔT6off.
42
(cont.)
Central heating without solar energy
Three-way diverter valve R6 rZ remains
at zero volt (position "AB-B") if the tem-
perature differential between buffer cyl-
inder temperature sensor S5 rW and
heating circuit return temperature sensor
S6 rT is less than temperature differen-
tial ΔT6off. There will be no flow through
heating water buffer cylinder rP.
Boiler 1 supplies the heating circuit
with heat according to the heating curve
set at boiler control unit 2.
A low loss header 6 with flow temper-
ature sensor 5 is required in conjunc-
tion with a wall mounted oil/gas
boiler.