Viessmann Vitoligno 300-P Service Instructions For Contractors page 78

Troubleshooting
Fault display
Fault codes
Fault code System characteris-
on the dis- tics
play
0F Control mode
10 Regulates as if the
outside temperature
were 0 °C
18 Regulates as if the
outside temperature
were 0 °C
20 Mixer closes
28 Mixer closes
30 Burner blocked
38 Burner blocked
39 Burner blocked
3A Emergency mode,
i.e. the secondary air
damper is put into a
fixed position and will
no longer be regula-
ted
40 Mixer closes
78
(cont.)
Cause
Maintenance
Short circuit, out-
side temperature
sensor
Lead break, out-
side temperature
sensor
Short circuit, flow
temperature sen-
sor, heating cir-
cuit 1
Break, flow tem-
perature sensor,
heating circuit 1
Boiler water tem-
perature sensor
faulty
Boiler water tem-
perature sensor
faulty
Flame temperature
sensor faulty
Break, Lambda
probe
Short circuit, flow
temperature sen-
sor, heating cir-
cuit 2
Measures
Service the appliance.
After servicing, set coding
address "24:0"
Check the outside tem-
perature sensor (see
page 87)
Check the outside tem-
perature sensor (see
page 87)
Check the flow tempera-
ture sensor (see
page 88)
Check the flow tempera-
ture sensor (see
page 88)
Check the boiler water
temperature sensor (see
page 85)
Check the boiler water
temperature sensor (see
page 85)
Check wiring and replace
flame temperature sen-
sor, if required
Check wiring and replace
Lambda probe, if
required
Check the flow tempera-
ture sensor (see
page 88)