Daewoo Air Conditioner Error Code 1

Error code 1 on a Daewoo air conditioner indicates a fault in the room air thermistor circuit. The room air thermistor is a negative temperature coefficient (NTC) resistor that feeds real-time ambient temperature data to the control PCB. The unit's microcontroller uses this signal to regulate compressor operation, fan speed, and target temperature. When the control board detects a resistance value outside the expected range, whether from an open circuit (infinite resistance) or a short circuit (near-zero resistance), it flags error code 1 and typically suspends normal operation to prevent incorrect temperature-based decisions.

The fault can originate at several points in the circuit: the thermistor itself, the wiring harness connecting it to the board, the connector pins, or the solder joints on the control PCB. Open circuits are commonly caused by broken wiring or a disconnected connector, while short circuits can result from pinched or damaged insulation allowing conductors to contact each other or a ground. Corroded or backed-out connector pins are also a frequent culprit, especially in units exposed to high humidity.

Diagnosing this fault requires inspecting the thermistor connector for secure seating and pin condition, visually checking the connecting wire for damage along its full length, examining solder joints on the PCB for cold or cracked connections, and measuring the thermistor resistance with a multimeter. A properly functioning room air thermistor should read a predictable resistance value corresponding to the ambient temperature, consistent with standard NTC thermistor characteristics. A reading of zero or infinite ohms confirms component or wiring failure.