Viessmann VITOTRONIC 100 Installation And Service Instructions Manual page 117

Faults which are displayed at the programming unit
Fault
System
code
characteristics
Control mode
b1
Emissions test
b4
mode
Control mode
bC 5
Constant mode
bC 6
Boiler is regulated
b7
by control
thermostat
Control mode
bC 8
bf
Boiler cools down
c1
Control mode
c2
Cause
Communication
error
Programming unit
Internal electronics
fault
Invalid
hardware ID
Boiler coding card
faulty
Lead broken
Flue gas
temperature sensor
Incorrect LON
communication
module
External safety
device
Lead broken
KM BUS to solar
control unit
Troubleshooting
(cont.)
Remedy
Check connections
and replace
programming unit if
necessary (see page
128)
Check electronics
PCB.
Replace, if required
Set code "92:160"
Plug in boiler coding
card or replace it, if
faulty (see page 60)
Checking flue gas
temperature sensor
(see page 132).
Without flue gas
temperature sensor
Set code "1F : 0"
Replace
communication
module
(see page 128)
Connection
Check plug aBÖ and
external safety
equipment
(see page 84)
Check KM BUS cable
and solar control unit
Without solar control
unit, set code "54 : 0"
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