Viessmann Vitotronic 200 Installation And Service Instructions For Contractors page 28

Electrical connections
External functions
External operating program changeover
Preselected operating program
(Contact open)
Central heating off / DHW
heating off
Central heating off / DHW
heating on
Central heating on / DHW
heating on
External blocking
!
Please note
Live contacts lead to short circuits or phase fail-
ure.
The external connection must be potential-
free.
Function
Control unit Vitotronic control unit
Connection Plug
1
A
B
Contact
Closed The boiler is blocked.
■
Shut-off devices are closed.
Note
There is no frost protection for the heating system.
Open The boiler is enabled.
■
Parameter Set parameter "07" in the "General" group. Set "42" (DE1), "43" (DE2) or "44" (DE3) in
28
(cont.)
Parameter
"1F:0" in the "Heating cir-
cuit..." group
(Factory setting)
"1F:1" in the "Heating cir-
cuit..." group
"1F:1" in the "Heating cir-
cuit..." group
.2/ .3
aVD aVD
A
2 3
143
B
Floating contact
Plug aVD of the control unit
Switched operating program
(Contact closed)
Continuous operation with reduced room
temperature / DHW heating off
Continuous operation with standard room
temperature, DHW heating in accordance
with coding address "0A" in the "DHW"
group
Continuous operation with standard room
temperature, DHW heating in accordance
with coding address "0A" in the "DHW"
group
External blocking
EA1 extension
DE1, DE2 or DE3
DE1
DE2
A A A
Floating contact
A
EA1 extension
B
the "General" group to 3 or 4.
B
DE3