Viessmann Vitodens 222-F B2TA series, Installation And Service Instructions Manual

Page: 124 / 196

124
Dis-
played
fault
code Const. Weath.-
comp. System char-
acteristics Cause Measures
50 X X No DHW heat-
ing Short circuit,
cylinder tem-
perature sen-
sor Check the cylinder
temperature sen-
sor (see
page 140)
51 X X No DHW heat-
ing Short circuit,
outlet temper-
ature sensor Check the outlet
temperature sen-
sor (see
page 142)
58 X X No DHW heat-
ing Lead break,
cylinder tem-
perature sen-
sor Check the cylinder
temperature sen-
sor (see
page 140)
59 X X No DHW heat-
ing Lead break,
outlet temper-
ature sensor Check the outlet
temperature sen-
sor (see
page 142)
A7 X Control mode
as per deliv-
ered condition Programming
unit faulty Replace program-
ming unit
A8 X Burner blocked
The venting
program is star-
ted automati-
cally (see
page 77) Air lock in the
internal circu-
lation pump
or minimum
flow rate not
achieved Vent the system if
the fault message
continues to be dis-
played
A9 X If a heating cir-
cuit with mixer
is connected,
the burner op-
erates at its
lower heating
output.
If only one
heating circuit
without mixer is
connected, the
burner is
blocked Internal circu-
lation pump
blocked Check the circula-
tion pump
Troubleshooting
Fault codes
(cont.)
5773 216 GB