Viessmann VITODENS 200-W Installation And Service Instructions Manual page 116

Troubleshooting
Fault codes
(cont.)
Dis- Const.
played
fault
code
A7
b0 X
b1 X
b5 X
b7 X
b8 X
bA
bb
116
Weath.- System char-
comp. acteristics
X Control mode
as per deliv-
ered condition
X Burner blocked Short circuit,
X Control mode
as per deliv-
ered condition
X Control mode
as per deliv-
ered condition
X Burner blocked Boiler coding
X Burner blocked Lead break,
X Mixer regulates
to 20 °C flow
temperature.
X Mixer regulates
to 20 °C flow
temperature.
Cause Measures
Programming Replace program-
unit faulty ming unit
Check flue gas
flue gas tem- temperature sen-
perature sen- sor
sor
Communica- Check connections
tion fault, pro- and replace pro-
gramming gramming unit if re-
unit quired
Internal fault Replace the control
unit
Plug in boiler cod-
card faulty ing card or replace
if faulty
Check flue gas
flue gas tem- temperature sen-
perature sen- sor
sor
Communica- Check extension
tion error, ex- kit connections and
tension kit for code.
heating circuit 2
(with mixer)
Communica- Check extension
tion error, ex- kit connections and
tension kit for code.
heating circuit 3
(with mixer)