Viessmann VITOTRONIC 200 Service Instructions Manual page 173

Refrigerant circuit
(cont.)
Message Meaning
code
0A Short circuit/lead break,
S
low pressure sensor
0B Short circuit/lead break,
S
secondary circuit flow
temperature sensor in the
appliance
0E Short circuit/lead break,
S
suction gas temperature
sensor
16 Parameter "Output com-
H
pressor stage 5030" not
set correctly
1E Controller PCB faulty
S
1F Parameter "Output com-
―
pressor stage 5030" not
set correctly
20 Condensing pressure too
H
high (control high pres-
sure)
21 Inadequate evaporation
H
pressure (low pressure
fault)
25 Operating point is outside
H
the application limits.
28 Max. high pressure
H
2F Min. required evaporation
H
pressure undershot
30 Secondary circuit return
H
temperature falls below
18 °C 4 times, one after
the other, prior to defrost-
ing.
39 Difference between flow
H
temperature in the appli-
ance and return tempera-
ture is larger than 12 K
prior to defrosting.
Heat pump characteris-
tics
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Both compressors OFF
Defrosting procedure does
not start.
Defrosting procedure does
not start.
Measure
Test voltage at the low pressure sen-
sor connection on the EEV PCB: See
"controller PCB and EEV PCB [6]".
0.5 V: 0 bar
■
4.5 V: Max. pressure, see sensor im-
■
print.
Check resistance value (NTC 10 k
at sensor connection on the controller
PCB: See "Controller PCB and EEV
PCB [6]".
Check resistance value (NTC 10 k
at sensor connection on the EEV PCB:
See "Controller PCB and EEV PCB
[6]".
Set "Output compressor stage
5030" according to the type plate.
Then switch off the heat pump control
unit. Wait 1 min. Then restart the heat
pump control unit.
Replace controller PCB.
Set "Output compressor stage
5030" according to the type plate.
Then switch off the heat pump control
unit. Wait 1 min. Then restart the heat
pump control unit.
As for "D4 Control high pressure":
See "Message overview" for the heat
pump control unit.
As for "D3 Low pressure": See "Mes-
sage overview" for the heat pump con-
trol unit.
Check the position of the operating
point: See "Compressor travel" and/or
"Compressor path".
Have a specialist check the com-
■
pressor parameters ("5xxx").
If necessary, reduce the set cylinder
■
temperature.
Check low pressure sensor: See
■
message code "0A".
Check refrigerant charge. Adjust if
■
necessary.
Reduce heat demand in the secon-
■
dary circuit, e.g. lower the set room
temperatures.
Reduce heat transfer in the secon-
■
dary circuit.
Reduce heat demand in the secon-
■
dary circuit, e.g. lower the set room
temperatures.
Reduce heat transfer in the secon-
■
dary circuit.
Diagnosis
)
Ω
)
Ω
173