Viessmann VITODENS 100-W Installation And Service Instructions Manual page 40

Troubleshooting
Fault messages on the display
Displayed System characteris-
fault code tics
b0 Burner blocked
b8 Burner blocked
E3 Burner in a fault
state
E5 Burner blocked
F0 Burner blocked
F1 Burner in a fault
state
F2 Burner in a fault
state
F3 Burner in a fault
state
40
(cont.)
Cause
Short circuit, flue
gas temperature
sensor
Lead break, flue
gas temperature
sensor
Fault in safety
chain.
Internal fault
Internal fault
Max. flue gas tem-
perature exceeded
The temperature
limiter has respon-
ded
Flame signal is
already present at
burner start
Measures
Check the sensor (see
page 47).
Check the sensor (see
page 47).
Check the temperature
limiter and connecting
leads (see page 45).
Check the control unit,
and replace if required.
Check the ionisation elec-
trode and connecting
cables.
Press "Reset" (see
page 42).
Replace control unit.
Check heating system fill
level. Check circulation
pump. Vent the system.
Press "Reset" (see
page 42).
Check heating system fill
level. Check circulation
pump. Vent the system.
Check the temperature
limiter and connecting
leads (see page 45).
Press "Reset" (see
page 42).
Check ionisation elec-
trode and connecting
cable.
Press "Reset" (see
page 42).