Viessmann VITOTRONIC 100 Installation And Service Instructions Manual page 10

Heating system designs
System version 1
Possible applications
Heating systems with distributor
installed close to the boiler. The
boiler water volume flow must be
able to be reduced.
If the factory−set temperatures are
not reached at the Therm Control
temperature sensor, Therm Control
will activate the heating circuit
control unit(s) or the heating circuit
pump(s). In the start−up phase (e.g.
during commissioning or after a
night or weekend shutdown), the
boiler water volume flow must be
reduced by at least 50 %.
The boiler is best protected when
regulating the heating circuits via
Vitotronic 050 connected to the
boiler control unit. No additional
on−site protective measures are
required.
10
(cont.)
Therm−Control
Wiring in heating systems with
heating circuit control units which
are not connected to the boiler
control unit via the LON BUS.
Required coding: "4C:
20
A1
20
N L
A
closed
B
sÖ A1 Mixers closed
A
Contactor relay,
part no. 7814 681
B
Downstream heating circuit
controller, contact closed:
Signal for "Mixer closed"
2".
closed closed