Lennox LIUH018021T431E-1 Service Manual page 133

2.4.4.2 Compressor Speed Malfunction/ Zero Speed Protection / Synchronous Fault Protection
LED1(Green) off/LED2(Red) flash
LED1(Green) off/LED2(Red) flash
or LED1(Green) flash/LED2(Red) on
or LED1(Green) flash/LED2(Red) on
Is there at least one LED in
Is there at least one LED in
the compressor driven chip
the compressor driven chip
light?
light?
No
Check the signal wire between
Check the signal wire between
the compressor driven chip and
the compressor driven chip and
the compressor. Is it connected
the compressor. Is it connected
properly?
properly?
No
Reconnect and retry. Is the
Reconnect and retry. Is the
error still displayed?
error still displayed?
Yes
Replace the outdoor main
Replace the outdoor main
PCB. Is the system running
PCB. Is the system running
normally?
normally?
No
Replace the compressor
Replace the compressor
Electrical Control System
Yes
Yes
No
Yes
Problem is resolved
Problem is resolved
Troubleshooting
131