Viessmann VITOTRONIC 200 Service Instructions Manual page 162

Diagnosis
Refrigerant circuit
Message Meaning
code
56 Condenser frost risk
H
59 Electronic expansion
S
valve faulty
5D Insufficient hot gas super-
H
heating
5F Communication error for
S
the following temperature
sensors:
Reversible suction gas
■
temperature sensor
Secondary circuit flow
■
temperature sensor (up-
stream of instantaneous
heating water heater)
Liquid gas temperature
■
sensor
69 Calculation error, refriger-
S
ant circuit
6A Air intake temperature too
H
low
6B H Air intake temperature too
high
6C Secondary circuit flow
H
temperature too high
6D Central cooling:
H
Secondary circuit flow
temperature too low
6E Defrosting:
H
Secondary circuit flow
temperature too low
6F H Compressor speed below
min. speed for 90 s
162
(cont.)
Heat pump characteris-
tics
Compressor OFF
■
Refrigerant circuit rever-
■
sal OFF
Compressor OFF
Compressor OFF
Compressor OFF
Compressor OFF
Compressor does not start. No action required
Compressor does not start.
Compressor does not start. If necessary, check the set tempera-
Compressor does not start. Check parameter settings for cooling
Compressor does not start.
Compressor OFF
Measure
Check hydraulics in the secondary
■
circuit, e.g. whether all shut-off
valves are fully open.
Check secondary circuit flow rate.
■
Check flow and return temperature
■
sensor in the secondary circuit: See
"Controller and sensor PCB".
Check amount of refrigerant. Adjust
■
the amount of refrigerant if necessa-
ry.
Check temperature sensors in the
■
refrigerant circuit: See "EEV PCB
[4-3] / [4-4]".
Check plug at connection J7: See
■
"EEV PCB [4-3] / [4-4]".
Check stepper motor of electronic
■
expansion valve.
Check hot gas temperature sensor:
See message code "04".
As for "EF Modbus subscriber": See
"Message overview" for the heat pump
control unit.
No action required: Compressor starts
up again.
tures of all heat sources in the heating
system. Adjust the set temperatures if
necessary.
("71xx"), e.g. "Min. flow temperature
cooling 7103".
As for "AA Cancel defrost": See
■
"Message overview" for the heat
pump control unit.
Add more heat from secondary cir-
■
cuit, e.g. via additional heating water
buffer cylinder in the return.
Check refrigerant circuit controller soft-
ware version: See chapter "System in-
formation".