Samsung Air Conditioner Error Code E190

The E190 error code on a Samsung air conditioner indicates a pipe test error related to the indoor unit evaporator inlet temperature sensor, designated EVA_IN. During a pipe test sequence, the system actively monitors temperature changes at the evaporator inlet to confirm refrigerant is flowing correctly through the intended indoor unit. The error triggers when either no measurable temperature difference is detected at EVA_IN, or when temperature changes are occurring in the wrong indoor unit's EVA_IN sensor. Both conditions indicate a mismatch or communication problem between the system's expectations and the actual refrigerant circuit behavior.

The most critical factor to investigate first is the indoor unit address configuration. In multi-split or VRF systems, each indoor unit is assigned a unique address so the outdoor unit and main controller can route commands and read sensor data from the correct unit. If the indoor unit's assigned address does not match the address set on the MCU (main control unit), the system will attempt to read temperature data from one unit while refrigerant is flowing through another. This creates the symptom of incorrect or absent temperature changes at the expected EVA_IN location. The MCU indoor unit setting switch must be inspected to confirm it matches the physical unit's address.

Secondary causes include a faulty EVA_IN temperature sensor that cannot register temperature changes even when refrigerant flow is present, refrigerant flow issues such as a restricted or closed service valve preventing adequate flow through the evaporator, or wiring faults causing sensor data to be misread or lost entirely. Resolving the address mismatch is always the recommended starting point before replacing any components.