Viessmann B2TF Installation And Service Instructions Manual page 83

Fault messages
(cont.)
Displayed fault System characteristics
code
F.92 Function of the relevant elec-
tronics module in emergency
mode
F.94 Function of the relevant elec-
tronics module in emergency
mode. No solar central heat-
ing backup.
F.100 Electronics modules connec-
ted to PlusBus not function-
ing
F.104 Depending on configuration
of EM-EA1 extension (DIO
electronics module)
F.142 Burner in a fault state
F.160 Burner in a fault state
F.161 Burner in a fault state
Cause
ADIO electronics module
communication error
SDIO electronics module
communication error
Voltage error PlusBus
External fault message in-
put active
Communication error,
CAN bus
Communication error,
CAN bus
BCU data memory access
error
Troubleshooting
Measures
Check setting in the commission-
■
ing assistant and correct if re-
quired.
Check connections and leads to
■
the ADIO electronics module.
Check PlusBus voltage level
■
(24 to 28 V).
Check subscriber number on ro-
■
tary switch S1 and correct if re-
quired.
Check setting in the commission-
■
ing assistant and correct if re-
quired.
Check connections and leads to
■
the SDIO electronics module.
Check PlusBus voltage level
■
(24 to 28 V).
Check whether the PlusBus power
supply on the HMU heat manage-
ment unit is OK: Remove all con-
nected PlusBus components and
reconnect one by one.
Check that there aren't more than
2 Vitotrol 200-E connected to the
HMU.
Check whether there is a short cir-
cuit at the PlusBus cable.
Check connected external device.
Check the fan unit for correct
■
function. For this, check the step-
per motor of the fan unit (refer-
ence run with mains ON).
If the fault still persists, visually
■
check the plug-in connections
and cables of the CAN bus.
Check further CAN bus subscrib-
■
ers.
If fault still persists, replace the fan
unit.
If "Connection error" is dis-
■
played, check the internal CAN
bus subscriber connections.
If only F.160 is displayed, check
■
the connections of the external
CAN bus subscribers.
Check the connecting cables for
■
secure seating and corrosion.
Reset the appliance.
Reset the appliance.
If fault recurs, replace BCU burner
control unit: See page 100.
83