Viessmann Vitodens 222-F B2TA Installation And Service Instructions Manual page 103

"Heating circuit ..."/group 5
Parameter address
A5:...
3
4
5
6
7
to
15
Coding in the delivered condition
A6:36 Extended economy con-
trol disabled (only for
weather-compensated
control units)
A7:0 Only for heating circuit
with mixer:
Without mixer economy
function (only for weath-
er-compensated control
units)
(cont.)
With heating circuit pump logic function: Heating cir-
cuit pump "OFF"
AT > RT + 3 K
set
AT > RT + 2 K
set
AT > RT + 1 K
set
AT > RT
set
AT > RT – 1 K
set
AT > RT – 9 K
set
Possible change
A6:5
to
A6:35
A7:1
Code 2
Extended economy control
enabled, i.e. the burner and
heating circuit pump will
stop and the mixer will be
closed at a variable value,
adjustable between 5 and
35 °C plus 1 °C. The base
value is the adjusted out-
side temperature. This val-
ue is based on the actual
outside temperature and a
time constant, which takes
the cooling down of an
average building into con-
sideration
With mixer economy func-
tion (extended heating cir-
cuit pump logic):
Heating circuit pump also
"OFF":
■ If the mixer has been
closed for longer than
20 min.
Heating circuit pump
"ON":
■ If the mixer changes to
control function
■ If there is a risk of frost
103