Fault Messages On The Display - Viessmann VITODENS 100-W Installation And Service Instructions Manual

Function sequence and possible faults
Yes
Burner in opera-
tion

Fault messages on the display

f
Displayed System characteris-
fault code tics
10 Constant mode
18 Constant mode
30 Burner blocked
38 Burner blocked
50 No DHW heating
No
Stops below the set
boiler water tem-
perature and
restarts immedi-
ately
2
Cause
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 fault code explanations see the fol-
lowing table.
Measures
Check the outside tem-
perature sensor and lead
(see page 41).
Check the outside tem-
perature sensor and lead
(see page 41).
Check the boiler water
temperature sensor (see
page 43).
Check the boiler water
temperature sensor (see
page 43).
Check the sensor (see
page 44).
Troubleshooting
37