Explanation Of The Alarms; Overview Of Fault Messages; Priority 1 Faults (System Switches Off) - Viessmann PLC VITOCAL 350-HT PRO Service Instructions For Contractors

Explanation of the alarms

■ The system is no longer in standard mode. The fault
should be remedied without delay.
The central fault message terminal is activated.
■
■ Messaging via a communication facility (website or
Modbus) is possible.

Overview of fault messages

Priority 1 faults (system switches off)

Note
The following faults may cause consequential dam-
age.
All faults that are marked with an additional "!" should
be reported to Viessmann Service before they are
acknowledged.
Do not acknowledge faults more than once.
If a fault remains active or occurs more than once,
please contact your heating contractor or Viessmann
Service.
ID Fault message
1! "EEV control"
2 "Sensor fault, outlet, con-
denser"
3 "Sensor fault, casing"
4 "Sens.fault,high press."
5 "Ext. set val, temp maint."
6 "Sensor fault low press."
7 "Sens. fault, suctn gas t 1"
8 "Sens. fault, suctn gas t 2"
9 "PLC CPU"
10 "Casing temp too high"
11 "Condensation temp too
high"
12 "Evaporation temp too low"
13 "Em. stop act."
14 "High pressure shutdown"
15 "Low pressure shutdown"
16 "Primary flow rate too low"
Effects
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
The system switches off
Troubleshooting
Possible cause
Defective electronic expansion valve
control. Evaporator superheating was
below 2 K for an extended period of time
Faulty temperature sensor at condenser
outlet
Casing temperature sensor faulty
High pressure sensor faulty
External set value from higher ranking
system is outside the range
Low pressure sensor faulty
Suction gas temperature sensor down-
stream of evaporator is faulty
Suction gas temperature sensor down-
stream of IHE is faulty
SPS (PLC) internal fault
The casing temperature has exceeded
the alarm value
The condensation temperature has ex-
ceeded the alarm value
The evaporation temperature has excee-
ded the alarm value
The emergency stop button has been
operated
The high pressure application limit has
been exceeded
The low pressure application limit has
been undershot
The primary flow rate (heat source) is too
low
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