Daewoo Air Conditioner Error Code E4

The E4 error code on a Daewoo air conditioner indicates that the system has detected a refrigerant gas leak. When this fault is triggered, the unit does not shut down entirely. Instead, it enters a protective operating mode where it continues running while attempting to maintain a fixed temperature: 18°C in heating mode or 32°C in cooling mode. The ON lamp blinks in a single-blink repeating pattern to signal this condition to the technician or user. This behavior is a deliberate design choice to provide partial climate control while alerting the operator that the refrigerant circuit has been compromised.

Refrigerant leaks in split-system air conditioners most commonly originate at flare connections, brazed joints, or service valves in the refrigerant piping. Over time, vibration, improper installation torque on flare fittings, or corrosion can allow small amounts of refrigerant to escape. When charge levels drop below the threshold needed for normal operation, the system's sensors detect abnormal pressures or temperatures and flag the E4 condition. The indoor and outdoor unit interconnecting pipe joints are the first area to inspect.

Diagnosing this code requires a physical inspection of all refrigerant piping for signs of oil staining, which often accompanies a leak point. A leak detection tool or soapy water solution applied to fittings and joints can help locate the escape point. Once the leak is found and repaired, the system must be properly evacuated and recharged with the correct refrigerant type and quantity before normal operation can resume. Refrigerant handling requires certified technicians in most regions.