Viessmann Vitocrossal 300 CA3 2.5 Installation And Service Instructions Manual page 82

Service
Operating the System
Boiler model 2.5 and 3.0
Legend
System and lead boiler section 1 control unit
A
Boiler section 2 control unit
B
Boiler model 3.5 to 6.0
Legend
System and lead boiler section 1 control unit
A
Boiler section 2 control unit
B
Boiler section 3 control unit (5.0 and 6.0 only)
C
82
(continued)
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
The control unit is pre-set, however several codings must
be set individually.
1. Activate the main switch and all network switches on
the control units.
2. Activate switch on the control unit. Start-up begins
automatically.
The following settings may be changed
"Language"
"Date and time"
"Temperature units"
"System layout"
"Elevation"
3. Confirm with OK, after which the prompt will appear:
"Do you want to make further changes".
IMPORTANT
With / , you can switch between codes.
After you have scrolled through all the codes,
a message appears to end operations.
IMPORTANT
Control unit A assumes the function of the boiler and
heating circuit control and of the system boiler section 1
control unit. Referred to below as Cascade control unit.
"Boiler section 1 + cascade" appears on the display.
The other control units assume the function of a lag boiler
control unit. Referred to as Boiler section 2/boiler section
3 control unit.