Viessmann VITOCAL 250-A - Page 158

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Measures
1. Check the number of additional CAN bus subscrib-
ers (e.g. slave heat pump and/or other Viessmann
appliances).
2. Disconnect the unsupported CAN bus subscriber
from the CAN bus system.
3. Check whether this disconnected CAN bus sub-
scriber can be connected to a main appliance in
another CAN bus system.
F.1009 Fault, heat pump electric compressor heating
F.1009
System characteristics
Refrigerant circuit off
Cause
Fault, oil sump heater
Measures
1. Check 6.3 A fuse on the VCMU refrigerant circuit
controller. Replace the fuse if necessary.
2. Check the function of the relay at X4.1/X4.2 on
the VCMU refrigerant circuit controller. If necessary,
replace VCMU refrigerant circuit controller.
3. Check the oil sump heater connections at X4.1 to
X4.2 on the VCMU refrigerant circuit controller:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
4. Check resistor R on the disconnected
plug X4.1/X4.2. If R < 1.256 kΩ or R > 1.388 kΩ,
replace oil sump heater.
F.1010 Water pressure sensor fault
F.1010
System characteristics
Refrigerant circuit off
Cause
Fault, water pressure sensor (heating water)
Measures
1. Check water pressure sensor including lead and
plug at X11.1 to X11.3 on EHCU electronics module
for damage.
2. Check voltage while system is operating (0 to 4 V).
If it deviates from the curve, replace pressure sen-
sor.
F.1011 Fault, high pressure sensor, refrigerant circuit
F.1011
System characteristics
Refrigerant circuit off
Cause
■
Fault, high pressure sensor
■
Further messages: A.82, A.93
Measures
1. Check the high pressure sensor and connec-
tions X14.1 to X14.3 on the VCMU refrigerant circuit
controller:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
2. Check voltage between X14.2/X14.3 in system
operation. If it deviates from the curve, replace the
high pressure sensor.
3. Replace VCMU refrigerant circuit controller.
Messages
Fault messages (cont.)
6218234
Diagnosis