Daewoo Air Conditioner Error Code 1 blink (ON lamp, 8s pattern)

This code indicates that the room temperature sensor circuit has been detected as open or short circuited by the indoor unit control board. The ON lamp blinks once in a repeating 8-second cycle to communicate this fault. The unit continues to run but operates with a fixed assumed room temperature of 32°C in cooling mode rather than using actual measured data. The sensor or its wiring needs to be inspected and tested.

The unit is designed to continue operating during this fault, so it will not shut down or create an immediate safety hazard. However, because cooling is based on a fixed 32°C reference rather than actual room temperature, the system cannot properly regulate output. Running it in this condition for extended periods is inefficient and may not maintain comfortable temperatures.

If only the room temperature sensor thermistor needs replacement, parts typically cost between $10 and $40 depending on the specific model, with professional labor adding $75 to $150 for the service call and repair. If the fault is traced to the control board, total repair costs can range from $150 to $350 or more. Cleaning a corroded connector is often a no-cost fix if done during routine maintenance.

A knowledgeable DIYer can check the sensor wiring connections and use a multimeter to test the thermistor resistance, which does not require accessing refrigerant lines or high-voltage components. If the thermistor has failed, replacing the room temperature sensor is a straightforward repair on most Daewoo indoor units. However, if the fault points to a control board issue, professional service is recommended.

A power reset may temporarily clear the fault display, but the code will return as soon as the control board re-reads the faulty sensor circuit. The underlying issue with the room temperature sensor or its wiring must be corrected before the fault will clear permanently. Repeated resets without repair do not resolve the problem.