D3 Low Pressure - Viessmann VITOTRONIC 200 Service Instructions Manual

Message overview
(cont.)

D3 Low pressure

Compressor stops.
Cause
Low pressure fault:
Heat pump faulty
■
Low pressure switch has responded.
■
Low pressure sensor has reported a fault.
■
Low pressure sensor faulty
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: Fan blocked or faulty
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Evaporator contaminated
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: Primary pump faulty
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D4 Control high pressure
Compressor stops.
Cause
High pressure fault:
Air in heating circuit
■
Secondary pump or heating circuit pump blocked
■
Condenser contaminated
■
High pressure sensor faulty
■
Measure
Clean the evaporator.
■
: Check fan.
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: Check pressure gauge, primary pump and shut-off
■
facilities.
Check low pressure switch/sensor at the following
■
connections:
–
Vitocal 100-S/111-S:
"LPP" connection on the main PCB: See "Main
PCB [7] / [7-1]".
– Vitocal 200-A/200-S/222-A/222-S:
Connection J10 on EEV PCB: See "EEV PCB
[4-3] / [4-4]".
–
Vitocal 200-A, type AWCI-AC 201.A:
Connection J4 on the EEV PCB: See "EEV PCB
[2]".
– Vitocal 222-G/333-G:
Connection J10 on EEV PCB: See "EEV PCB
[4-6] / [4-7]".
–
Vitocal 300-A, type AWO-AC 301.B:
Connection J10 on the EEV PCB: See "EEV PCB
[4]".
– Vitocal 300-A, type AWO 302.B:
Connections J4 and J7 on the controller PCB: See
"Controller PCB [6]".
Check cable and main PCB/EEV PCB. Replace PCB
■
if required. See "Main PCB [7] / [7-1]", "EEV PCB
[4-3] / [4-4]" or "EEV PCB [4-6] / [4-7]".
Have the heat pump checked by a refrigeration engi-
■
neer.
Measure
Vent heating circuit.
■
Check the system pressure.
■
Check secondary pump and heating circuit pumps.
■
Flush heating circuits.
■
Troubleshooting
99