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

Fault messages on the display

f
Fault code System characteris-
on display tics
10 Constant mode
18 Constant mode
30 Burner switched off
38 Burner switched off
50 No DHW heating
58 No DHW heating
60 Burner switched off
68 Burner switched off
A9 Control mode without
Open Therm device
Faults are indicated by a flashing fault
code with fault symbol "U" on the dis-
2
play.
For fault code explanations see the fol-
lowing table.
■ Flashing fault symbol "U": To reset
■ Constantly displayed fault symbol "U":
Cause
Short circuit, out-
side temperature
sensor
Outside tempera-
ture sensor lead
broken
Short circuit, boiler
water temperature
sensor
Boiler water tem-
perature sensor
lead broken
Terminal box cylin-
der demand fault
Terminal box cylin-
der demand fault
Short circuit, return
temperature sen-
sor
Return tempera-
ture sensor lead
broken
Communication
fault Open Therm
device
press "U RESET" (see page 30) after
the fault has been remedied
Will automatically reset after the fault
is remedied
Measures
Check outside tempera-
ture sensor and lead (see
page 31).
Check outside tempera-
ture sensor and lead (see
page 31).
Check boiler water tem-
perature sensor (see
page 33).
Check boiler water tem-
perature sensor (see
page 33).
Check terminal box con-
nections and replace ter-
minal box if required.
Check terminal box con-
nections and replace ter-
minal box if required.
Check return temperature
sensor (see page 33).
Check return temperature
sensor (see page 33).
Check connections and
lead; replace Open Therm
device if required.
Troubleshooting
27