LG Air Conditioner Error Code E702

E702 indicates that the indoor unit's Electronic Expansion Valve has been detected in a closed or non-responsive state during the first detection cycle. The EEV controls refrigerant flow through the indoor coil, and when it fails to open on command the system logs this fault. This is classified as a first-detection event, meaning it is an early warning before the system escalates to a more critical fault state.

Pressing the reset key K3 is a required step after addressing the underlying cause, but pressing it without fixing the root problem will only temporarily clear the display. If the EEV wiring, coil, or valve issue has not been corrected, the error will return once the system attempts to operate again. Always resolve the physical fault before resetting.

Repair costs depend on which component has failed. If the issue is simply a loose wire or corroded connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing an EEV coil or the full EEV assembly will add parts and labor costs, generally bringing the total into the $200 to $600 range depending on the model and local labor rates.

Some steps, such as checking the EEV wire connections for looseness and inspecting terminals for visible rust, can be performed by a knowledgeable DIYer comfortable working inside the indoor unit. However, measuring coil resistance accurately requires a multimeter and some electrical knowledge. Any work involving refrigerant or the EEV assembly itself should be handled by a licensed HVAC technician.

Running the unit continuously with an E702 fault is not recommended. A closed EEV prevents proper refrigerant metering, which can lead to inefficient operation, potential compressor stress from refrigerant imbalance, and possible escalation to a more serious fault. The unit should be inspected and repaired before resuming normal use.