Viessmann Vitocal 350-A Installation And Service Instructions Manual page 156

Troubleshooting
Control unit diagnostics
Position Code
10 1
2
Example:
Information index "0C : 0C 00 00 00"
Posi- Display
tion
1 "0"
2 "C"
— ":"
3 "0"
4 "C"
5 "0"
6 "0"
7 "0"
8 "0"
9 "0"
10 "0"
Temperature and pressure values
Most recent temperature and pressure values captured in primary and secondary
circuits.
156
(cont.)
Explanation
Maximum operating pressure (MOP) was reached; control type
(superheating/evaporation pressure control) in refrigerant cir-
cuit was adjusted.
Fault due to impermissible combination of refrigerant circuit
conditions. A serious EEV controller fault has occurred, as the
heat pump control unit only transfers permissible parameter
combinations to the EEV controller.
Codes Explanation (Tab. E)
(Tab. C)
0 —
4 High pressure sensor faulty, determined from a
plausibility check of values
8 Hot gas temperature sensor faulty, determined
from a plausibility check of values
— —
0 —
4 High pressure sensor faulty, reported directly from
EEV controller
8 Hot gas temperature sensor faulty, reported
directly from EEV controller
0 —
0 —
0 —
0 —
0 —
0 —