LG Air Conditioner Error Code E190

E190 on an LG air conditioner indicates a pipe inspection fault where no temperature change was detected at the evaporator inlet (EVA IN) sensor during the system's self-check routine. It can also appear when temperature changes are being reported by an indoor unit configured with an incorrect address in a multi-zone installation. The error points to a problem with the EVA IN thermistor, refrigerant flow, wiring, or system addressing.

Continuing to operate the unit with E190 active is not recommended. The error indicates the system cannot confirm proper refrigerant flow or temperature behavior at the evaporator inlet, which could mask underlying issues like low refrigerant or a failing component. Running the system under these conditions risks further damage to the compressor or other components.

Repair costs depend on the root cause. Reconfiguring an address setting is typically inexpensive and may only involve a service call fee, generally in the range of $75 to $150. Replacing an EVA IN thermistor usually falls in the $100 to $250 range including parts and labor. Refrigerant recharge or PCB replacement will cost more, often between $200 and $600 or higher, depending on system size and local labor rates.

Some causes of E190, such as an incorrect indoor unit address setting, can be corrected without special tools if you are comfortable navigating the system's configuration menu. However, checking the EVA IN thermistor resistance, inspecting wiring connections, and assessing refrigerant charge all require technical knowledge and, in the case of refrigerant work, EPA certification. Most homeowners should contact a qualified HVAC technician for this repair.

A power reset may temporarily clear the error, but if the underlying cause, such as a faulty sensor, wiring fault, or incorrect address, has not been corrected, the E190 code will return once the system runs its pipe inspection routine again. A reset should be used as part of the diagnostic process, not as a fix on its own.