157
Measures
1. Check the following sensors and connections on
the VCMU refrigerant circuit controller:
■
Heating mode: Secondary circuit flow temperature
sensor at X15.3/X15.4
■
Cooling mode: Air intake temperature sensor
at X15.3/X15.4
■
Oil sump temperature sensor at X20.3/X20.4
■
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.
Check resistor R for NTC 10 k
Ω
on the disconnected
plug. Replace sensor if required.
2. Check 6.3 A fuse at X2.3A/X2.3B of VCMU refriger-
ant circuit controller. Replace the fuse if necessary.
Check relay contact at X4.1/X4.2 on VCMU refriger-
ant circuit controller for correct function.
3. Check the oil sump heater and connec-
tions X4.4A to X4.10A on the VCMU refrigerant cir-
cuit 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.
Check resistor R on disconnected plug. If
R < 1.256 kΩ or R > 1.388 kΩ, replace oil sump
heater.
F.1007 Heat pump locked
F.1007
System characteristics
Refrigerant circuit locked
!
Please note
Escaping refrigerant will cause environmental
pollution.
Do not unlock refrigerant circuit multiple times in
quick succession.
Cause
Cause of fault depends on other fault message with
which it is combined
Measures
1. Perform steps according to the other fault message:
F.864, F.881, F.984, F.985, F.1006, F.1074, F.1076,
F.1077, F.1078
2. Unlock refrigerant circuit via ViGuide.
F.1008 Number of supported devices on main control unit exceeded
F.1008
System characteristics
The most recently connected additional CAN bus sub-
scriber is not recognised by the (master) heat pump
(main appliance).
Cause
■
Max. number of 15 additional CAN bus subscribers
(e.g. slave heat pump and/or other Viessmann appli-
ances) has been exceeded.
■
Further messages: I.96, I.97, I.98
Messages
Fault messages (cont.)
6218234
Diagnosis
To Next Page