Fault Codes - Viessmann VITODENS 242-F Installation And Service Instructions Manual

Fault codes

Displayed System characteris-
fault code tics
0F Control mode
10 Controls as if the out-
side temperature
were 0 °C
18 Controls as if the out-
side temperature
were 0 °C
19 Controls as if the out-
side temperature
were 0 °C
20 Regulates without
flow temperature
sensor (low loss
header)
28 Regulates without
flow temperature
sensor (low loss
header)
30 Burner blocked
38 Burner blocked
Cause
Service
"0F" is only dis-
played in the fault
history
Short circuit, out-
side temperature
sensor
Lead break, out-
side temperature
sensor
Communication er-
ror, wireless out-
side temperature
sensor
Short circuit, sys-
tem flow tempera-
ture sensor
Lead break, sys-
tem flow tempera-
ture sensor
Short circuit, boiler
water temperature
sensor
Lead break, boiler
water temperature
sensor
Troubleshooting
Measures
Service required
Note
After servicing, select
code "24:0".
Check outside tempera-
ture sensor (see
page 139)
Check outside tempera-
ture sensor (see
page 139)
Check wireless connec-
tion (place wireless out-
side temperature sensor
close to the wireless base
station). Log off outside
temperature sensor then
log on again. Replace if
required (see "Wireless
base station" installation
and service instructions).
Check low loss header
sensor (see page 140)
Check low loss header
sensor (see page 140)
If no low loss header sen-
sor is connected, set code
52:0
Check boiler water tem-
perature sensor (see
page 140)
Check boiler water tem-
perature sensor (see
page 140)
125