Viessmann VITOCAL 300-A Installation And Service Instructions Manual page 127

Control unit diagnostics
6. "ÓH" for hours run by the heat
pump in a particular load
situation. See table
"Hours run according to
load classes"
Displays
Display Description
I (—) The last 4 digits designate the version of the hardware and soft-
ware of the heat pump module (example: 0000 0000 0000).
Tsh, Tc Tsh: Set temperature, overheating
(°C) Tc: Set condensation temperature
Pmop (bar) Max. operating pressure
Ts, Tc (°C) Ts: Actual suction temperature, overheating
Tc: Actual condensation temperature
Ps (bar) Actual suction pressure
Pc (bar) Actual condensation pressure
TI (°C) Actual LPG temperature
x (%) Set position of electronic expansion valve
P (%) Set compressor output
Err (—) Electronic expansion valve fault.
For explanations see the following table.
Faults at the electronic expansion valve
Display
Err 00: 01000000
Err 00: 02000000
Err 00: 04000000
Err 00: 08000000
Err 00: 10000000
Err 00: 20000000
Further temperatures, pressures and fault messages
Display Description
tpe Primary input heat pump 1
tpa Primary output heat pump 1
tse Secondary return heat pump 1 and 2
tsa Secondary flow for heat pump 1
P0 Evaporation pressure heat pump 1 and 2
(cont.)
Description
Suction pressure sensor faulty
Suction gas temperature sensor faulty
Condensation pressure sensor faulty
Condensation temperature sensor faulty
LPG temperature sensor faulty
Stepper motor electronic expansion valve (EEV)
faulty
Troubleshooting
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