Viessmann VITOCAL 300 - What to Do If...; Troubleshooting Guide

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What to do if ...
Troubleshooting guide
Any fault in the heat pump will be shown in the display field, when the flap is
closed. In addition the control unit indicates, what you should do in case of
various types of fault.
For heat pumps with two compressor stages:
The control unit starts the second compressor stage if the first compressor
stage drops out. This provides you with heating until you can arrange a
repair.
What to do if ...
Cause Remedy
... A0 or A1 is displayed No fault/external control
... the display appears
dark
Power failure/
mains supply has failed/
incorrect phase
sequence
The heat pump starts up
automatically, as soon
as the power is restored
or the fault is remedied
Fuse dropped out/blown Notify your local
specialist
... A3 is displayed Type BW:
Brine pressure too low
or
Type WW:
Flow switch activated
Notify your local
specialist
... A4 is displayed No faults: Off−period
imposed by your local
electricity supplier
... A5 or A6 is displayed Safety switch activated Notify your local
specialist
... A7 is displayed Type AW:
Ventilation duct clogged
Check and clean the
ventilation duct
Type BW:
Primary circuit leaks,
primary pump faulty
or
Type WW:
Intermediate circuit
leaks, intermediate
circuit pump faulty
Check pressure gauge
and primary pump;
notify your local
specialist
5592 415GB