Viessmann B1HF Installation And Service Instructions Manual page 71

Fault messages
(cont.)
Displayed fault System characteristics
code
102 No internet connection
103 Control mode
104 Depending on configuration
of EM-EA1 extension (DIO
electronics module)
142 Burner in a fault state
160 Burner in a fault state
161 Burner in a fault state
163 Burner in a fault state
182 No DHW heating
183 No DHW heating
184 Burner in a fault state
185 Burner in a fault state
Cause
Error with communication
module
Internal communication
error, programming unit
External fault message in-
put active
Communication restriction
on CAN bus. INR
Communication error,
CAN bus
HBMU heat management
unit data memory access
fault
Checksum error, data
memory access, HBMU
heat management unit
Short circuit, outlet tem-
perature sensor (if instal-
led)
Lead break, outlet temper-
ature sensor (if installed)
Short circuit, flow temper-
ature sensor/high limit
safety cut-out
Lead break, flow tempera-
ture sensor/high limit safe-
ty cut-out
Troubleshooting
Measures
Check cables and plug-in connec-
tions between heat management
unit and communication module.
Check cables and plug-in connec-
tions between heat management
unit and HMI programming unit.
Check connected external device.
Check the fan unit for correct func-
tion. For this, check the stepper
motor of the fan unit (reference run
with mains ON).
If the fault persists, check the plug-
in connections and cables of the
CAN bus.
Check further CAN bus subscrib-
ers. If fault occurs repeatedly, re-
place fan unit.
Check connection to CAN bus sub-
scribers (INR, HBMU).
Check connections to external
CAN bus subscribers.
Reset the appliance.
If the fault occurs repeatedly, re-
place the HBMU heat management
unit. See chapter "Replacing the
HBMU heat management unit".
Reset the appliance.
If the fault occurs repeatedly, re-
place the HBMU heat management
unit. See chapter "Replacing the
HBMU heat management unit".
Check outlet temperature sensor
(plug X7, cores 3 and 4). Measure
sensor input on HBMU heat man-
agement unit. Set value: 3.3 V
with sensor disconnected
Check outlet temperature sensor
(plug X7, cores 3 and 4).
Check the flow temperature sen-
sor/high limit safety cut-out.
Check sensor lead. Replace faulty
component if required.
Reset the appliance.
Check the flow temperature sen-
sor/high limit safety cut-out. Re-
place faulty component if required.
Reset the appliance.
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