Diagnosis via fault table
Note
Initially check the equipment for loose connecting cables.
Fault
Possible cause
Remedy
Limited heating output
Extremely low outside
temperature, see
page 53
The standby LED of the
internal device does not
illuminate
No mains voltage (or too
low) at the PCB term-
inals (internal device)
Check power supply
PCB (internal device)
faulty
Replace PCB
The equipment cannot be
switched ON;
The ON/OFF LED of the
internal device does not
illuminate
Remote control batteries
dead
Replace batteries
Faulty connection be-
tween PCB (internal de-
vice) and
display PCB (receiver
PCB for duct mounted
devices)
Check connection
Display PCB (receiver
PCB for duct mounted
devices) faulty
Replace PCB
PCB (internal device)
faulty
Replace PCB
No air delivery at the in-
ternal device
Equipment in heating
mode and heat exchan-
ger not yet warm
Switch to cooling mode
and check
No/low voltage at the fan
connection of the PCB
Select high speed; if vol-
tage at the motor
< 130 V
–
: Replace PCB
Fan capacitor faulty
Replace capacitor
Fan motor faulty
Replace motor
Poor connection be-
tween impeller and fan
motor shaft
Tighten impeller
Diagnosis
(cont.)
25
Troubleshooting
5692
689
GB