Viessmann VITOLIGNO 300-P Service Instructions Manual page 14

Commissioning, inspection, maintenance
Further details regarding the individual steps
If the heating circuits are regulated via
Vitotronic 200 (type FO1) 2, heating
circuit pumps M1 eE and M2 rE stop,
and mixers M1 eR and M2 rR are
closed, subject to absolute priority being
enabled.
With modulating priority (recommen-
ded), heating circuit pumps M1 eE and
M2 rE remain switched on, and mixers
M1 eR and M2 rR are closed far enough
for the set boiler water temperature
required for cylinder heating to be ach-
ieved. DHW cylinder qP and heating cir-
cuits eP and rP will then be heated
simultaneously.
Heating mode
In accordance with the control unit used,
the flow temperature of heating circuits
eP and rP is modulated subject to the
outside temperature. The boiler water
temperature is regulated 8 K higher than
the set flow temperature or the minimum
boiler water temperature of 60 °C.
The heating circuit pump is switched on
via the heating circuit pump logic, provi-
ded there is a heat demand.
DHW heating by the solar thermal
system with Vitosolic (two heating
circuits)
For systems with two heating circuits
with mixer or if additional solar control
unit functions are required (e.g. heating
the solar preheat stage and switching the
transfer pump), use a Vitosolic solar con-
trol unit.
14
If Vitosolic 100 (type SD1) wZ is connec-
ted via the KM BUS to Vitotronic 200
(type FO1) 2, solar control unit infor-
mation (e.g. collector temperature, cylin-
der temperature, solar circuit pump
hours run and solar yield) can be dis-
played on the Vitotronic 200 or Vitotrol
300.
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 qP 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
(cont.)