Viessmann VITOTRONIC 100 Installation And Service Instructions Manual page 82

Installation
External hook−up in multi−boiler systems without LON
Adjustments on every control unit
Set code "01: 3".
The high limit safety cut−out settings
and other settings are subject to the
system equipment and the safety
equipment in accordance with
DIN 4751 2.
Enable boiler, butterfly valve
Contact closed:
The burner can be externally
switched. The butterfly valve opens.
Contact opened:
The butterfly valve is closed after
approx. 5 min. Burner stages cannot
be started externally.
82
Starting burner stage 1
Contact closed:
Burner stage 1 is started. The boiler
water temperature is limited by the
electronic maximum temperature
limiter, if it is set below that of
mechanical control thermostat "R".
Contact opened:
Burner stage 1 is shut down.
(cont.)