A8 Heating Circ. Pump Hc1 - Viessmann VITOTRONIC 200 Service Instructions Manual

Troubleshooting
Message overview
Cause
Secondary pump mechanical fault
■
Secondary pump electrical fault
■
Secondary pump run dry
■

A8 Heating circ. pump HC1

Temperature increase in heating circuit without mixer
A1/HC1.
Cause
No flow (circulation pump shut down).
A9 Heat pump
Compressor is switched off.
■
Central heating and DHW heating occurs with other
■
heat sources enabled for this purpose, e.g. an exter-
nal heat generator or instantaneous heating water
heater.
■ The operation with booster heaters depends on the
setting "Operating status after message A9, C9
701C".
Cause
Heat pump faulty
■
Safety high pressure switch has responded: See "C9
■
Refrigerant circ (SHD)".
One of the following events has occurred:
■
–
High pressure limit was exceeded 3 times within
60 min (Vitocal 100-S/111-S only).
–
Low pressure limit was undershot twice within
40 min (Vitocal 100-S/111-S only).
– Flow switch has responded 9 times.
– Compressor was switched off by the refrigerant cir-
cuit controller 9 times.
–
Defrosting process was terminated.
Note
The event counter is reset as soon as the compressor
has been operational continuously once for "Opti-
mum runtime compressor 500A".
Safety chain is interrupted for more than 24 h.
■
Event that leads to the compressor being switched off
■
is active for more than 24 h.
Primary/secondary circuit flow and return temperature
■
sensors are simultaneously faulty for more than 24 h.
92
(cont.)
Measure
Carry out mechanical check of secondary pump.
Measure the voltage at the following connections:
Vitocal 222-G:
■
Connections J5 and J17 on the EEV PCB: See "EEV
PCB [4-6] / [4-7]".
Vitocal 333-G:
■
Connections J5 and J20 on the EEV PCB: See "EEV
PCB [4-6] / [4-7]".
Other heat pumps:
■
Connection 211.2: See "Main PCB".
Replace the secondary pump if required.
Measure
Measure voltage at terminal 212.2 (see "main PCB")
and check pump mechanically; replace if necessary.
Measure
Calling up further heat pump messages: "Message
■
history"
Observe messages from the refrigerant circuit con-
■
troller: "Diagnosis" "Refrigerant circuit"
sage history"
Check flow rates.
■
Check safety high pressure switch.
■
Check flow and return temperature sensors in the pri-
■
mary/secondary circuit.
Note
After removing the fault, switch the appliance first off
and then on again.
"Mes-