System Diagnosis
Low Pressure Switch Open. The low pressure switch is open (Cooling/Heat Pump).
Troubleshooting guide for the Lennox E-Codes system fault E223.
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 16 Lennox fault codes and asks the right questions to narrow it down.