Display shows “dEF” or “DEFROST”; unit pauses heating and fan may stop while compressor continues intermittently.

Safety first: Keep clear of moving fan blades and high‑voltage components.

• Observe operation: In cool or damp weather, frost on the evaporator coil is normal. The unit will periodically enter defrost (dEF) to melt ice. No action is needed if it resumes heating afterward.
• Check airflow: Ensure nothing blocks the top discharge or side air inlets. Restricted airflow can cause excessive icing.
• Inspect coil: If the coil is heavily iced and the unit stays in dEF for long periods, shut power off and allow ice to melt completely. Then clean the coil and restart.
• Sensor check: If dEF appears constantly in mild weather, the defrost or coil sensor may be faulty. Have a technician test and replace the sensor or control board as needed.