Viessmann VITOLIGNO 300-P Service Instructions Manual page 33

Further details regarding the individual steps
System version 4 — Vitoligno 300-P with one or two heating circuits with mixer,
multi mode heating water buffer cylinder and solar thermal system
Function description
The heating circuits eP and rP are regu-
lated by control unit Vitotronic 200, type
FO1 2 of the Vitoligno 300-P 1. The
boiler will only start if there is a demand
for DHW heating or from a heating cir-
cuit. The time program for heating mode
and heating up of the multi mode heating
water buffer cylinder qR is set at the
boiler control unit.
The heating circuit pumps are switched
on via the heating circuit pump logic, pro-
vided there is a heat demand.
Mixing valve 4 in the return tempera-
ture raising facility holds the boiler return
water at a minimum of 45 °C. Set the
water circulation volume of boiler circuit
1 so that a temperature spread of 15 K
between the boiler flow and return
results at the rated boiler heating output.
The boiler shuts down if neither the multi
mode heating water buffer cylinder qR
nor the heating circuits eP and rP issue
any demands.
Upon demand, the boiler is operated with
the required set boiler water temperature
or the minimum boiler water temperature
of 60 °C. Any DHW demand is given pri-
ority; the heating circuit pumps eE/rE
are stopped and the mixers eR/rR are
closed. When the set DHW cylinder tem-
perature is reached, the system changes
over to heat the heating circuits eP/rP.
Commissioning, inspection, maintenance
Boiler 1 and boiler circuit pump 5 start
if the actual temperature at buffer tem-
perature sensor tQ falls below the set
heating circuit temperature. The boiler
shuts down and the boiler circuit pump
runs on for approx. 10 min when the
actual temperature at buffer temperature
sensor falls approx. 6 K below the tem-
perature set for the heating circuits.
Heating up the heating water buffer
cylinder and raising the return tem-
perature
Boiler 1 and boiler circuit pump 5 start
if the actual temperature at buffer tem-
perature sensor tQ falls below the tem-
perature set for heating circuits eP/rP or
cylinder qR. The boiler shuts down and
the boiler circuit pump runs on for
approx. 10 min when the actual temper-
ature at buffer temperature sensor tW
falls below the set temperature for the
heating circuits. Mixing valve 4 in the
return temperature raising facility holds
the boiler return water at a minimum of
45 °C. Set the water circulation volume
in the boiler circuit of the Vitoligno 300-P
so that a temperature spread of 15 K
between the boiler flow and return
results at the rated boiler heating out-
put.
(cont.)
33