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

Troubleshooting
Function sequence and possible faults
Yes
Burner in opera-
tion

Fault display

Displayed System characteris-
fault code tics
10 Constant tempera-
ture mode
18 Constant tempera-
ture mode
30 Burner blocked
38 Burner blocked
50 No DHW heating
62
No
Stops below the set
boiler water tem-
perature and re-
starts immediately
f 2
(cont.)
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.
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
Check the flue sys-
tem for tightness
(flue gas recircula-
tion); check the
gas flow pressure
Measures
Check the outside tem-
perature sensor and lead
(see page 66).
Check the outside tem-
perature sensor and lead
(see page 66).
Check boiler water tem-
perature sensor (see
page 68).
Check boiler water tem-
perature sensor (see
page 68).
Check sensor (see
page 69).