Viessmann Vitoclima 300-S Service Instructions For Contractors page 27

Diagnosis
(cont.)
Fault
Compressor overheated;
insufficient output; equip-
ment enters fault state
and compressor switches
OFF without obvious rea-
son
No output, although all
components operate cor-
rectly
Condensate pan of the
internal device overflows
Water drips from the bot-
tom of the external unit
One or several indicators (LED) do not function correctly
Precondition: Normal heating and cooling output.
Check connection between the PCB
of the internal device and the dis-
play PCB (receiver PCB on duct
mounted devices).
Check display PCB or receiver PCB
and replace, if required
Check the PCB of the internal
device and replace, if required.
Possible cause
Electronic expansion
valve faulty
Controller or refrigerant
circuit faulty
Refrigerant leak; refrig-
erant circuit does not
function correctly
Internal device not level
(horizontally)
Condensate pan drain or
drain pipe blocked
Drain pipe incorrectly
routed
For cassette device:
Condensate pump does
not start
Condensate drain
blocked
Troubleshooting
Remedy
Check expansion valve
and replace, if required
Scan fault code (see
page 16)
Fix leak; fill system with
refrigerant
Level internal device
(horizontally)
Remove blockage
Route the drain pipe with
a slope of at least 2 %
Check sensors for con-
densate level, controller
and pump
Open external unit; re-
move blockage; clean the
bottom of the equipment
interior
27