Viessmann VITODENS 200-W Installation And Service Instructions Manual page 96

Troubleshooting
Fault messages
(cont.)
Displayed fault System characteristics
code
19 Regulates as if the outside
temperature were 0 °C.
20 Regulates without flow tem-
perature sensor (low loss
header).
21 Control mode
Display fault in energy cock-
pit
22 Control mode
Display fault in energy cock-
pit
23 Control mode
Display fault in energy cock-
pit
24 Control mode
Display fault in energy cock-
pit
25 Control mode
Display fault in energy cock-
pit
26 Control mode
Display fault in energy cock-
pit
27 Control mode
Display fault in energy cock-
pit
28 Regulates without flow tem-
perature sensor (low loss
header).
2A Control mode
Display fault in energy cock-
pit
30 Burner blocked
38 Burner blocked
40 Mixer is being closed.
44 Mixer is being closed.
48 Mixer is being closed.
96
Cause
Communication interrup-
tion, outside temperature
sensor RF
Short circuit, system flow
temperature sensor
Sensor outside tolerance
range
Sensor outside tolerance
range
Incorrect commissioning
DHW circulation pump not
working
Transfer pump not work-
ing
DHW circulation pump
and transfer pump not
working
Incorrect commissioning
Lead break, system flow
temperature sensor
Solar circuit flow and re-
turn interchanged.
Short circuit, boiler water
temperature sensor
Lead break, boiler water
temperature sensor
Short circuit, flow temper-
ature sensor, heating cir-
cuit 2 (with mixer)
Short circuit, flow temper-
ature sensor, heating cir-
cuit 3 (with mixer)
Lead break, flow tempera-
ture sensor, heating circuit
2 (with mixer)
Measures
Check wireless connection. Place
outside temperature sensor RF
close to the boiler.
Forget outside temperature sensor,
then pair again (see separate
documents).
Replace outside temperature sen-
sor RF.
Check low loss header sensor (see
page 111).
Check sensors in the DHW cylin-
der and collectors.
Check sensors in the DHW cylin-
der and collectors.
Determine solar circuit flow rate
and enter value established.
Check setting of parameter 39
("General" group). If required, car-
ry out an actuator test.
Check setting of parameter 20
("Solar" group). If required, carry
out an actuator test.
Check settings of parameter 39
("General" group) and parameter
20 ("Solar" group). If required,
carry out an actuator test.
Determine solar circuit flow rate
and enter value established.
Check low loss header sensor (see
page 111)
If no low loss header sensor is
connected, set parameter 52:0.
Check solar circuit flow and return
and swap over if required.
Check boiler water temperature
sensor (see page 111)
Check boiler water temperature
sensor (see page 111)
Check flow temperature sensor
(see page 117).
Check flow temperature sensor
(see page 117).
Check flow temperature sensor
(see page 117).