Viessmann VITODENS 111-W Installation And Service Instructions Manual page 56

Troubleshooting
Fault display
Displayed System characteris-
fault code tics
51 No DHW heating
58 No DHW heating
59 No DHW heating
A9 Control mode without
OpenTherm device
b0 Burner blocked
b8 Burner blocked
E3 Burner in a fault
state
E5 Burner blocked
F0 Burner blocked
F1 Burner in a fault
state
56
(cont.)
Cause
Short circuit, outlet
temperature sen-
sor
Lead break, cylin-
der temperature
sensor
Lead break, outlet
temperature sen-
sor
Communication er-
ror, OpenTherm
device
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
Measures
Check sensor (see
page 63).
Check sensor (see
page 62).
Check sensor (see
page 63).
Check connections and
lead; replace OpenTherm
device if required.
Check sensor (see
page 65).
Check sensor (see
page 65).
Check the temperature
limiter and connecting ca-
bles (see page 64).
Check the control unit,
and replace if required.
Check the ionisation elec-
trode and connecting ca-
bles.
Press "Reset" (see
page 58).
Replace control unit.
Check heating system fill
level. Check circulation
pump. Vent the system.
Press "Reset" (see
page 58).