Fault Codes - Viessmann VITOLADENS 300-W Installation And Service Instructions Manual

Troubleshooting

Fault codes

Displayed System characteris-
fault code tics
10 Regulates as if the
outside temperature
were 0 °C
18 Regulates as if the
outside 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
40 Mixer closes
44 Mixer closes
48 Mixer closes
4C Mixer closes
50 No DHW heating by
the boiler
96
Cause
Short circuit, out-
side temperature
sensor
Lead break, 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
Short circuit, flow
temperature sen-
sor, heating circuit
2 (with mixer)
Short circuit, flow
temperature sen-
sor, heating circuit
3 (with mixer)
Lead break, flow
temperature sen-
sor, heating circuit
2 (with mixer)
Lead break, flow
temperature sen-
sor, heating circuit
3 (with mixer)
Short circuit, cylin-
der temperature
sensor
Measures
Check outside tempera-
ture sensor (see
page 104)
Check outside tempera-
ture sensor (see
page 104)
Check low loss header
sensor (see page 105)
Check low loss header
sensor (see page 105).
If no low loss header sen-
sor is connected, set code
52:0
Check boiler water tem-
perature sensor (see
page 105)
Check boiler water tem-
perature sensor (see
page 105)
Check flow temperature
sensor (see page 111)
Check flow temperature
sensor (see page 111)
Check flow temperature
sensor (see page 111)
Check flow temperature
sensor (see page 111)
Check sensors (see
page 105)