Technical data

8. MALFUNCTIONS
8.1 Troubleshooting Chart – COMFOAIR 140
Fault/malfunction Symptom Display Check
Bypass rotates Bypass
Filter clogged FiltEr/A1 Filter
Bypass
A3 Intake air PTC thermistor
A4 Exhaust air PTC thermistor
None
Bypass does not
rotate
E3 Discharged air PTC thermistor
“Intake air” button
Fuse on pcb defective Voltage connected
Control pcb defective
All OFF
No voltage Failure of mains voltage
3-position switch
High air delivery
temperature in summer
Bypass remains
closed
Bypass Comfort
temperature
A3 Intake air PTC thermistor
A4 Exhaust air PTC thermistor
A5 Malfunction in outside
temperature PTC thermistor
A7 Malfunction in post-heater
temperature PTC thermistor
Bypass Low air delivery
temperature in winter
Bypass remains
open
E3 Discharged air PTC thermistor
Comfort temperature
E2 Fan defective
E2 Fan power pack defective
Control pcb
Fan not running
E3 PTC thermistor
Filter clogged
Valves clogged
Heat exchanger clogged by
soiling
Heat exchanger iced
- Deviation in PTC thermistor
- Control pcb
Fan soiled
Ducts clogged
Air intake fan speed reduced
due to frost risk
No or insufficient intake
air
Fan running
Air intake fan is switched off
due to extreme frost risk