Viessmann VITOTRONIC 100 Installation And Service Instructions Manual page 32

Heating system designs
System version 9
Codes must be set on every Vitotronic 100.
Required coding
01 : 2 Multi−boiler system with cascade control via LON BUS
01 : 3 Multi−boiler system with external cascade control via switching
contacts
02 : 2 Modulating burner operation
03 : 1 Oil fired operation (irreversible)
0C : 1 Constant return temperature control
Boiler circuit pump on plug sL
4d : 2
Automatic changeover
Connecting temperature sensor T1 to plug aJA
4A: 1
Possible applications
e.g. older heating systems and/or
systems in nurseries where
downstream heating circuits cannot
be controlled.
The cascade and cylinder control
must be provided by a higher control
unit.
Temperature sensor T1 closes the
three−way mixing valve in proportion
and therefore ensures boiler
protection if the required minimum
return temperature is not achieved.
*1
If required.
32
(cont.)
*1
*1
Note
Size the boiler circuit pumps for each
boiler so that their volume flow is at
least as large as the max. total
heating circuit volume flow.
Recommendation: 110 %