Daewoo Air Conditioner Error Code E4

The E4 code on a Daewoo air conditioner means the system has detected a refrigerant gas leak. Instead of shutting down, the unit enters a failsafe mode and continues operating at a fixed temperature: 18°C in heating mode or 32°C in cooling mode. The ON lamp blinks in a single repeating pattern to signal this fault. A qualified technician should inspect all refrigerant piping and joints to locate and repair the leak.

Modern residential air conditioners use refrigerants that are generally low in acute toxicity at typical leak volumes in a well-ventilated space. However, refrigerant displaces oxygen in enclosed areas and can pose an asphyxiation risk in very confined spaces with a significant leak. You should ventilate the area, avoid open flames near the unit if you suspect a substantial leak, and have the system inspected promptly.

Repair costs vary depending on where the leak is located and how much refrigerant has been lost. A simple flare fitting tightening and recharge is typically less expensive, often in the range of $150 to $350. Repairs involving coil replacement or extensive pipe work can range from $400 to $900 or more depending on parts and labor rates in your area. Getting a diagnostic inspection first will give you a clearer cost estimate.

Locating a leak by visually inspecting pipe joints for oily residue is something a knowledgeable DIYer can do. However, repairing a refrigerant leak and recharging the system with refrigerant requires certified equipment and is regulated in most countries, so that portion of the repair must be handled by a licensed technician. Attempting to simply add refrigerant without finding and fixing the leak will only result in the E4 code returning.

Resetting the unit may temporarily clear the E4 display, but the code will return as long as the refrigerant leak condition persists. The unit's sensors will continue detecting the abnormal pressure or temperature caused by low refrigerant charge and re-trigger the fault. The only way to permanently clear E4 is to repair the leak and restore the correct refrigerant charge.