Viessmann B1HF - Detailed Fault Causes and Resolution Steps

67
Displayed fault
code
System characteristics Cause Measures
7 No DHW heating. Lead break, cylinder tem-
perature sensor
■
Check DHW setting in the com-
missioning assistant and correct
if required.
■
Check the cylinder temperature
sensor (terminal 2).
■
Measure voltage at sensor input
on HBMU heat management
unit. Set value: 3.3 V– with sen-
sor disconnected.
Replace faulty component if re-
quired.
8 No DHW heating Short circuit, cylinder tem-
perature sensor
Check the cylinder temperature
sensor (terminal 2).
Replace faulty component if re-
quired.
11 No solar DHW heating or
central heating backup
Lead break, collector tem-
perature sensor
■
Check collector temperature sen-
sor.
■
Measure voltage at sensor input
on electronics module (ADIO).
Set value: 3.3 V– with sensor dis-
connected
12 No solar DHW heating Short circuit, collector
temperature sensor
■
Check collector temperature sen-
sor.
■
Measure voltage at sensor input
on electronics module (ADIO).
Set value: 3.3 V– with sensor dis-
connected
13 Controls as if the outside
temperature were 0 °C
Lead break, outside tem-
perature sensor
■
Check operating mode setting in
commissioning assistant and
remedy if required.
■
Check outside temperature sen-
sor and connection to sensor
(terminal 4).
■
Measure voltage at sensor input
on HBMU heat management
unit. Set value: 3.3 V– with sen-
sor disconnected.
Replace faulty component if re-
quired.
14 Controls as if the outside
temperature were 0 °C
Short circuit, outside tem-
perature sensor
Check outside temperature sensor
and connection to sensor (terminal
4). Replace faulty components if
necessary.
15 No solar DHW heating Lead break, solar cylinder
temperature sensor (bot-
tom)
Check cylinder temperature sen-
sor.
Measure voltage at sensor input on
ADIO electronics module. Set val-
ue: 3.3 V
–
with sensor disconnec-
ted
16 No solar DHW heating Short circuit, solar cylinder
temperature sensor (bot-
tom)
Check cylinder temperature sen-
sor.
Measure voltage at sensor input on
ADIO electronics module. Set val-
ue: 3.3 V
–
with sensor disconnec-
ted
Troubleshooting
Fault messages (cont.)
6167586
Diagnosis