Viessmann VITOLIGNO 300-P Service Instructions Manual page 20

Commissioning, inspection, maintenance
Further details regarding the individual steps
The heating circuit pump is switched on
via the heating circuit pump logic, provi-
ded there is a heat demand. Upon
demand, the boiler is operated with the
required set boiler water temperature or
the minimum boiler water temperature of
60 °C.
The boiler shuts down if neither the DHW
cylinder nor the heating circuits issue
any more demands.
DHW heating by the solar thermal
system with Vitosolic
For systems with two mixer heating cir-
cuits or if additional solar control func-
tions are required (e.g. heating the solar
preheat stage and switching the transfer
pump), use a Vitosolic solar control
unit.
If the Vitosolic 100 (type SD1) is connec-
ted via the KM BUS to the Vitotronic 200
(type FO1), solar control unit information
(e.g. collector temperature, cylinder tem-
perature, solar circuit pump hours run
and solar yield) can be displayed on the
Vitotronic 200 or Vitotrol 300A.
20
(cont.)
If the temperature differential between
collector temperature sensor wQ and cyl-
inder temperature sensor qT exceeds
the start temperature differential, solar
circuit pump wE starts, and DHW cylin-
der qR is heated up.
The pump is switched off if:
■ The actual temperature drops below
the stop temperature differential
■ The electronic temperature limit is
exceeded
■ The temperature selected at the high
limit safety cut-out (if installed) is
reached