Fault Display - Viessmann VITODENS 111-W Installation And Service Instructions Manual

Function sequence and possible faults
Yes
Burner in opera-
tion

Fault display

f
Displayed System characteris-
fault code tics
0C Burner blocked
10 Constant operation
18 Constant operation
30 Burner blocked
38 Burner blocked
50 No DHW heating
No
Stops below the set
boiler water tem-
perature and re-
starts immediately
2
Cause
Mains voltage too
low
Short circuit, out-
side temperature
sensor
Lead break, out-
side temperature
sensor
Short circuit, boiler
water temperature
sensor
Lead break, boiler
water temperature
sensor
Short circuit, cylin-
der temperature
sensor
(cont.)
Check the flue sys-
tem for tightness
(flue gas recircula-
tion); check the
gas flow pressure
Faults are indicated by a flashing fault
code with fault symbol "U" on the dis-
play.
For an explanation of the fault codes,
see the following table.
Measures
Check power supply.
Check the outside tem-
perature sensor and lead
(see page 59).
Check the outside tem-
perature sensor and lead
(see page 59).
Check boiler water tem-
perature sensor (see
page 61).
Check boiler water tem-
perature sensor (see
page 61).
Check sensor (see
page 62).
Troubleshooting
55