Control Functions - Viessmann FB2B Installation And Service Instructions Manual

External extensions (accessories)
Function assignment
Select the function of output aBJ via
code 36 at the boiler control unit.

Control functions

External heating program changeover
The "External heating program change-
over" function is connected via extension
EA1. There are 3 inputs available at
extension EA1 (DE1 to DE3).
Heating program changeover
Input DE1
Input DE2
Input DE3
Assign the heating program changeover
function for the respective heating circuit
via code d8 at the boiler control unit:
Heating program changeover
Changeover via input DE1
Changeover via input DE2
Changeover via input DE3
You can select which direction the heat-
ing program changeover takes in coding
address "d5":
Heating program changeover
Changeover towards "Permanently reduced" or "Permanent
standby" mode (subject to the selected set value)
Changeover towards "Constant heating mode"
The duration of the heating program
changeover can be adjusted in coding
address "F2":
Function description
(cont.)
The function is selected via the following
codes:
Code
3A:1
3b:1
3C:1
Code
d8:1
d8:2
d8:3
Code
d5:0
d5:1
135