Additional functions for single boiler systems with Vitotronic 200, type GW1B or Vitotronic 300, type GW2B
or GW4B
Plug
aVD
143
B
A
1 2 3
A
External heating program changeover/mixer "open"
B
External blocking/mixer "close"
A
and
B
are floating contacts.
External heating program changeover/mixer "open"
Closing contact
A
can change the manually selected heating pro-
gram or open the connected mixers.
In coding address "9A", the external function mixer "open" can be allo-
cated to the individual heating circuits.
In coding address "91", the external heating program changeover can
be allocated to the heating circuits.
Heating programs
Symbol
Explanation
9
Central heating OFF and DHW OFF
w
Central heating OFF and DHW ON
rw
Central heating ON and DHW ON
Subject to the setting of coding address "d5", the system can be
switched over from all three manually adjustable heating programs
9
,
w
and
rw
(contact open), to either
9
or
rw
(contact closed).
External blocking/mixer "close"
Closing contact
B
causes the burner to shut down or the mixer to be
closed.
In coding address "99" you select which heating circuits are affected
by the function external blocking or mixer "close".
Note
The frost protection of the relevant boiler or heating circuit is no longer
effective during the controlled shutdown or when the mixer "Closes",
The lower boiler water temperature or flow temperature will no longer
be maintained.
Plug
aVH
146
B
A
1 2 3
A
■ For GW1B and GW2B, external changeover of stepped/modu-
lating burner
■ For GW4B, external burner blocking
B
External demand
A
and
B
are floating contacts.
External demand
Closing contact
B
starts the burner of the boiler depending on load.
The boiler water temperature is limited via the maximum set boiler
water temperature or via the mechanical temperature controller.
The set value is selected in coding address "9b".
External changeover of multi stage/modulating burners
■ Contact
A
open:
Modulating operation
■ Contact
A
closed:
Two-stage operation
Set coding address "02" accordingly.
Additional functions for single boiler systems with Vitotronic 200, type GW1B or Vitotronic 300, type GW2B
or GW4B via EA1 extension
Connection of on-site control units for weather-compensated
mode to the extension EA1
External demand via 0 – 10 V input
Connection to the 0 – 10 V input on the
extension EA1
.
In conjunction with a two-stage or modulating burner.
Control units
(cont.)
Gas condensing boilers
VIESMANN
89
5822 449 GB
9