Samsung Air Conditioner Error Code E103

E103 indicates an open or short circuit fault on the EVAP OUT sensor, which is the thermistor mounted at the outlet of the indoor evaporator coil. The control board monitors the resistance from this sensor and triggers the error when the reading falls outside acceptable limits. This can be caused by a loose connector, a failed thermistor, or damaged wiring.

Running the unit while E103 is active is not recommended. The EVAP OUT sensor helps the system prevent evaporator freeze-up and manage compressor cycling. Operating without a functioning sensor can cause the unit to ice over, short-cycle, or place unnecessary strain on the compressor over time.

A power reset may temporarily clear the E103 code if the fault was caused by a momentary signal glitch, but the error will return if the underlying problem is not resolved. If the sensor connector is loose or the thermistor has failed, the fault will reappear as soon as the unit runs through its startup diagnostics. A reset is useful for confirming whether the fault is intermittent, but it is not a substitute for proper diagnosis.

The first step is one most homeowners can handle: check that the sensor connector is firmly seated on the indoor PCB, which sometimes requires removing the front panel. If the connector is secure, testing the thermistor resistance requires a multimeter and some comfort working with electronics. Replacing the sensor is a straightforward repair, but if the indoor control board is the cause, professional service is recommended.

If the fix is simply reseating a loose connector, there is no parts cost. Replacing the EVAP OUT thermistor is generally an inexpensive repair, with sensor parts typically ranging from $15 to $50 depending on the model. If a technician is needed, expect labor costs on top of parts, with total repair estimates commonly ranging from $75 to $200.