Viessmann Vitoclima 300-S Service Instructions For Contractors page 23

Diagnosis
(cont.)
Fault Fault
code
07 No feedback external fan/com-
pressor
08 Processor fault external fan
09 External fan idle
10 Max. speed of the external fan
exceeded
11 Compressor processor fault
12 Compressor idle
13 Max. compressor speed ex-
ceeded
14 Excessive compressor power
consumption
15 DC undervoltage
16 DC overvoltage
17 AC undervoltage
18 No connection to the internal
device A
19 No connection to the internal
device B
20 No connection to the internal
*
device C
21 No connection to the internal
device D
*1
Not applicable to type OT307H.
1
Troubleshooting
Cause/Remedy
Check the connections of the ex-
ternal fan (voltage and velocity
sensor); check the fan motor;
check the compressor connec-
tion and motor
Overheating/overvoltage at the
external fan controller; air inlet
blocked; motor jumper incor-
rectly placed on the controller;
check external fan motor
Check external fan
Wind-influenced excess air inlet
on the suction side; if required, fit
wind break; electromagnetic
faults
Overheating/overvoltage at the
compressor speed controller; air
inlet blocked; check compressor
motor
Checking the compressor
Restart; if problem persists, re-
place controller
Checking the compressor
DC voltage below limit; replace
controller
Check mains voltage (max.
264 V~); if OK then replace con-
troller
Check mains voltage (min.
198 V~); if OK then replace con-
troller
Check the connecting cable be-
tween the internal device, the ex-
ternal unit and earth
23