4 red flashes / green OFF
System in low-pressure switch lockout
This code typically points to
- Low charge
- Evaporator airflow issue
- LPS opening >5 sec outside ignore windows
Next checks to confirm
- Verify refrigerant circuit and airflow
- Note LPS is ignored during first 2 minutes of compressor run
Escalation
Repeated soft lockouts escalate to hard lockout.
Reset behavior
Soft lockout logic.
Urgent
Fix now