Daewoo Air Conditioner Error Code 0 blinks (continuous ON blink)

The continuous ON blink pattern indicates the room temperature sensor has been detected as open or short circuited. The micom control board reads an input voltage either below 0.3V (open) or above 4.7V (short), both of which are outside the valid sensor range. As a result, the unit enters failsafe mode and fixes the room temperature target to 32°C during heating operation rather than responding to actual room conditions.

The unit will continue operating in failsafe mode, so it is not immediately dangerous. However, because the room temperature is fixed at 32°C in heating mode rather than being regulated by actual sensor feedback, the system cannot respond correctly to real room conditions. Running in this state for extended periods wastes energy and prevents accurate temperature control, so prompt repair is recommended.

A power reset will temporarily clear the fault indication, but the error will return immediately if the underlying sensor problem has not been corrected. Because the micom checks the sensor voltage at startup and during operation, any open or short circuit condition will trigger the failsafe mode again as soon as the unit restarts. The fault will only stay cleared after the defective sensor, wiring, or connector has been repaired or replaced.

A knowledgeable DIYer can check the sensor connector for corrosion or looseness and inspect the wiring harness for visible damage without specialized tools. Measuring voltage at the micom sensor input pin requires a multimeter and basic electrical knowledge. Replacing the room sensor itself is a straightforward part swap, but if the control board is the underlying cause, board replacement is more involved and may warrant a qualified technician.

If only the room temperature sensor needs replacement, parts typically range from around 10 to 40 dollars depending on the specific model. Professional labor for diagnosis and sensor replacement generally adds 60 to 150 dollars. If the control board requires replacement, total repair costs can range from 150 to 400 dollars or more depending on part availability and labor rates in your area.