System Diagnosis
Hard lockout active.
Troubleshooting guide for the American Standard AC and Heat Pump system fault Green LED (Intermittent Flash – 1 flash every 4 sec).
Pressure and temperature readings that stay out of range after airflow is verified.
Dirty coils or airflow restrictions can look like a charge problem until the air side is cleaned up.
ACLogics has guided diagnostics for 36 American Standard fault codes and asks the right questions to narrow it down.