Viessmann VITOTRONIC 200 Service Instructions Manual page 150

Diagnosis
Refrigerant circuit
Message Meaning
code
1A Safety chain interrupted,
S
compressor blocked
20 Condensing pressure too
H
high (control high pres-
sure)
21 Inadequate evaporation
H
pressure (low pressure
fault)
26 Max. defrost time excee-
H
ded
27 Compression ratio too
H
high
28 Max. high pressure
H
2A Inverter power consump-
H
tion too high
2B Max. suction gas pressure
H
exceeded
2C Min. pressure differential
H
between high and low
pressure side has not
been reached.
2D Compression ratio too low Compressor OFF
H
2E Min. required high pres-
H
sure undershot
150
(cont.)
Heat pump characteris-
tics
Compressor OFF
Compressor OFF
Compressor OFF
Defrost is terminated early.
Compressor OFF
Compressor OFF
Compressor OFF
Compressor OFF
Compressor OFF
Compressor OFF
Measure
Check safety chain: See connection
■
and wiring diagram.
Check plug for compressor control
■
on the EEV PCB: See "EEV PCB
[2]".
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 setting of "Evaporator tem-
■
perature for defrost end 5010".
Restore factory settings if necessary.
Check function of 4-way diverter
■
valve: See "Actuator test".
If fault persists, notify a specialist.
■
Check high and low pressure sen-
■
sors: See message codes "05" and
"0A".
If the pressure sensors are OK but the
fault persists:
Check the position of the operating
■
point: See "Compressor travel"
and/or "Compressor path".
If necessary, reduce the set cylinder
■
temperature.
Have a specialist check the com-
■
pressor parameters ("5xxx").
If necessary, reduce the set cylinder
■
temperature.
Test coil resistance at compressor. Re-
sistance on all windings must be simi-
lar ( 10 %). For m use a suitable
± Ω
measuring device.
Check refrigerant charge. Adjust if
■
necessary.
If fault persists, notify a specialist.
■
Check high and low pressure sen-
■
sors: See message codes "05" and
"0A".
If the pressure sensors are OK but the
fault persists:
Check inverter power connections.
■
Check whether the compressor is
■
still running at a constant speed af-
ter starting: See "Refrigerant circuit
controller [2]". Replace compressor
if necessary.
Check high pressure sensor: See
■
message code "05".
Check refrigerant charge. Adjust if
■
necessary.